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R-1051 - 07/14/2009 - HISTORIC GATEWAY CORRIDOR - Resolutions Supporting Documents1 • , V 0 AGENDA ITEM Regular Board of Trustees Meeting of July 14, 2009 SUBJECT: Graue Mill Dam FROM: David Niemeyer, Village Manager BUDGET SOURCE/BUDGET IMPACT: ITEM 10,B, I) : :ri RECOMMENDED MOTION: That the Village Board approve Resolution R -1051, A Resolution In Opposition To Proposed Changes To The Graue Mill Dam In The Village Of Oak Brook, Illinois. Background /History: The DuPage River Salt Creek Workgroup (DRSCW) is proposing to recommend to the DuPage County Forest Preserve modifications to or removal of the Graue Mill Dam. Because of the historical significance and the gain of only minimal improvements in water quality, fish population and habitat quality on Salt Creek, the Village Board and interested residents have expressed opposition to this. Recommendation: That the Village Board approve this Resolution. Last saved by administiator J \ALL D0CS\2a- MEM0S- B0T \Graue Mill doc Last printed 7/9/2009 3 16 PM RESOLUTION 2009 -HGC -R -1051 A RESOLUTION IN OPPOSITION TO PROPOSED CHANGES TO THE GRAUE MILL DAM IN THE VILLAGE OF OAK BROOK, ILLINOIS WHEREAS, the Forest Preserve District of DuPage County (Forest Preserve) owns and maintains the Graue Mill Dam which is located in the Historic Graue Mill Gateway Corridor in the corporate limits of the Village of Oak Brook, Illinois, and WHEREAS, the Graue Mill is listed in the National Register of Historic Landmarks, as well as serving as part of the Underground Railroad for slaves traveling North to escape bondage, and WHEREAS, the Village President signed a Proclamation on September 10, 2002 celebrating the 150th Anniversary of Graue Mill and Museum, and WHEREAS, the DuPage River Salt Creek Workgroup (DRSCW) is proposing to forward recommendations to the Forest Preserve which would compromise, and perhaps destroy, the historical integrity and scenic beauty of the dam at the Graue Mill ; and WHEREAS, the recommendations of the DRSCW do not include a recommendation that would preserve the present dam structure, and WHEREAS, if executed, the recommended alterations would provide only minimal improvements in water quality, increase in fish population and quality of habitat on Salt Creek, and WHEREAS, the Village President and Board of Trustees find that the interests of the Village of Oak Brook would not be best served by the removal or modification of the Graue Mill Dam NOW, THEREFORE, BE IT RESOLVED by the President and Board of Trustees of the Village of Oak Brook, DuPage and Cook Counties, Illinois, as follows - Section 1 That the Village President and Board of Trustees for the Village of Oak Brook hereby express their collective opposition to any action to restore the free and unimpeded flow of the water through Salt Creek by removing and /or modifying the Graue Mill Dam and direct the Village's representative on the DRSCW to vote against these recommendations and the forwarding of same to the Illinois Environmental Protection Agency Section 2 That the Village Manager communicate to other governmental entities of the DRSCW the Village Board's decision and reasons for same and request their support of the Village's position Section 3 All resolutions or parts of resolutions in conflict with this resolution are hereby repealed to the extent of the conflict. Section 4 This resolution shall be in full force and effect from and after its passage, approval and publication as required by law APPROVED THIS 14th day of July, 2009. John W Craig Village President PASSED THIS 14t" day of July, 2009 Ayes Nays. Absent ATTEST Charlotte K Pruss Village Clerk Resolution 2009 -HGC -R -1051 Resolution Opposing Removal or Modification of Graue Mill Dam Page 2 of 2 J AGENDA ITEM Regular Board of Trustees Meeting of May 19, 2009 SUBJECT: Salt Creek/Graue Mill Dam — IEPA Water Quality Item Total Maximum Daily Loads (TMDLs) FROM: Dale L. Durfey, Jr., P.E., Village Engineer BUDGET SOURCE/BUDGET IMPACT: N.A. RECOMMENDED MOTION: Staff is seeking Board input. Background/History: In 2000, the Illinois Environmental Protection Agency (IEPA), in response to pressure from the USEPA, began a process of measuring the water quality of the surface waters of the State, and what water quality impairments still needed to be addressed. The IEPA analysis of Salt Creek (and the East Branch and West Branch of the DuPage River) was finally published in 2004 and reported that all three rivers were "impaired" and did not meet water quality standards as stipulated under the Federal Clean Water Act. The final IEPA report intimated that future effluent limits would be forthcoming to which both sanitary sewer treatment plants and municipal storm sewer systems would have to comply. The final report established initial Total Maximum Daily Loads (TMDLs), defined as the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards. In response to this report, many agencies within DuPage County (and several outside DuPage but along the rivers) met and formed the DuPage River Salt Creek Workgroup to work with IEPA to find the best way to address the remaining impairments and bring the rivers into compliance with the Clean Water Act goals (Attachment 1 is the current membership). The Workgroup has been collecting and analyzing data for over 3 years. Various public meetings /workshops have been held and brochures /public information items created to inform Last saved by administrator J: \WORDDOC \TMDL P &BT 5 -19 -09 agenda doc Last printed 5/14/2009 11:30 AM CA the public and gather comments (e.g., Attachment 2 is a March 2006 newsletter dealing with dissolved oxygen on Salt Creek and East Branch DuPage River and mentions a 2nd public workshop held on March 9, 2006 at College of DuPage). The Workgroup's website is www.drscw.org which contains information and reports. As of March 2009, no specific plans for Salt Creek have been approved for implementation, only concepts have been identified and discussed. The lake impoundment upstream of the Graue Mill dam has been identified as a significant area of degradation. Two meetings were held in March at the Oak Brook Village Hall in an attempt to inform the public about the impairments and possible alternatives. The collection and analyzing of data will continue as will the dissemination of information to the public. The following members of the DuPage River Salt Creek Workgroup will present a brief history of the water quality issues and the draft "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek" report to the Village Board on Tuesday, May 19, 2009: 1. Stephen McCracken, an employee of the Conservation Foundation 2. Dennis Streicher, Director of Water and Wastewater, City of Elmhurst, and currently President of the Workgroup 3. Tom Richardson, chairman of the Salt Creek Watershed Committee and Oak Brook resident After the presentation, the presenters will answer questions. The Workgroup will be reviewing the "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek" report at its June 24th meeting and voting to approve it. The Workgroup will be sending a draft report to IEPA by the end of May and then must send the final report to IEPA after June 24th since IEPA funded the study through a grant. The Workgroup will be adding recommendations to the report with the goal of apprising the IEPA of recommended mitigation options dealing with the dissolved oxygen impairment. Staff is looking for direction from the Village Board regarding how it should vote regarding approval of the report at the June 24th meeting. Recommendation: That the Board provide direction to staff regarding how it should vote regarding approval of the report at the Workgroup's June 24th meeting. Last saved by administrator J: \WORDDOC \TMDL P &BT 5 -19 -09 agenda doc Last printed 5/14/2009 11.30 AM DuPage River /Salt Creek Workgroup 2007 -8 Dues Paid by Agency Dues Paid by Agency Members May 1 2008 Agency Members Primary Cont, Primary Cont,. Primary Contact Title 2tone e-mail Secondary Contacl Secondary Contac Addison Village of Addison J. Mitchell Patterson Public Works Superin (630) 279 -2140 mpatterson @addison- il.org Gregory Brunst Arlington Heights Village of Arlington Hj Dennis Bowe Superintendent of Util (847) 368 -5800 dbowe @vah.com Scott Shirley Aurora Barrington Bartlett Batavia Bensenville Village of Bensenville Paul Quinn Director of Public Woi (630) 350 -3435 pquinn @bensenville.il us Berkeley Bloomingdale Village of Bloommgd. Michael Marchi Director of Village Ser (630) 671 -5691 marchim @vil.bloomingdale.il.us Robert Maguire Bolingbrook Village of Bolingbrool Wade Jacobi Assistant to the Direc (630) 226 -8872 wjacobi @bolingbrook.com Michael Drey Broadview Brookfield Carol Stream Village of Carol Strea James Knudsen Village Engineer (630) 871 -6220 JKNUDSEN @carolstream org Bill Cleveland Clarendon Hills Darien Deer Park Downers Grove Village of Downers G Michael Millette Assistant Director of F (630) 434 -5494 mmillette @downers.us Naneil Newlon Downers Grove SD Downers Grove Sani Nick Menninga General Manager nmenninga @dgsd org Larry Cox DuPage County DuPage County Kevin Buoy Operations Manager (630) 985 -7400 KBuoy @dupageco.org Tony Charlton Elk Grove Village Elk Grove Village Thomas Cech Director of Public Woi (847) 734 -8043 tcech @elkgrove.org Vito Sammarco Elmhurst City of Elmhurst Dennis Streicher Director (630) 530 -3046 dennis.strelcher @elmhurst.org Wayne Pochert Franklin Park Glenbard WW Autho Glenbard Wastewate Erik Lanphier Wastewater Manager (630) 790 -1901 elanphier@gbww.org David Goodalis Glen Ellyn Village of Glen Ellyn Joe Caracci Public Works Director (630) 469 -6756 jcaracci @glenellyn.org Bob Minix Glendale Heights Village of Glendale H Guy Marino Superintendent (630) 260 -6040 gmarino @glendaleheights org Rick Dime Hanover Park Village of Hanover Ps Howard Killan Director of Public Woi (630) 372 -4441 hkillan @hanoverparkillinois.org Larry Stahl Hillside Hinsdale Village of Hinsdale Dan Deeter Village Engineer (630) 789 -7039 ddeeter @villageofhinsdale org All Diaz Hoffman Estates Village of Hoffman E! Kenneth Han Director of Public Woi (847) 490 -6800 Ken Hari @HoffmanEstates.org Haileng Xiao Inverness Itasca Village of Itasca Fred Maier Nature Center Directc (630) 228 -5652 fmaier @itasca com Glen Sullivan Lisle Village of Lisle Ray Peterson Public Works Director (630) 271 -4171 rpeterson @villageoflisle org Mary Lou Kalsted Lombard Village of Lombard David Gorman Acting Director of Put (630) 620 -5765 gormand @villageoflombard org Paul Kuehnlenz Maywood Melrose Park MWRDGC Metropolitan Water F Manju Sharma Manju.sharma @mwrd.org Naperville City of Naperville Erskine Klyce City Engineer (630) 420 -6103 klycee @naperville it us Dave Van Vooren Northlake City of Northlake Dale Roberts Superintendent of Pul (708) 562 -0940 suptpw @comcast.net Liz Biddle Oak Brook Village of Oak Brook Dale Durfey Village Engineer (630) 368 -5130 ddurfey @oak - brook.org David Niemeyer Oakbrook Terrace City of Oakbrook Ter Paul Bourke Stormwater Admirnstr (847) 823 -0500 pbourke @cbbel com Craig Ward Palatine Rolling Meadows Roselle City of Roselle Michael Higgins Village Engineer (630) 980 -2020 mhiggins @roselle il.us John LaRocca Salt Creek SD Salt Creek Sanitary C Fred Dale Manager (630) 832 -3664 freddale @sbcglobal net Schaumburg Village of Schaumbw Robert Covey Development Review (847) 9234736 rcovey @ci schaumburg.il us Martha Dooley St Charles South Barrington Stone Park Streamwood Villa Park Village of Villa Park Rick Cermark Superintendent (630) 834 -8505 nckc @invillapark com Vydas Juskelis Warrenville Wayne West Chicago City of West Chicagc Greg Koch Assitant Director of P (630) 293 -2255 gkoch @westchicago.org Rob Flatter Westchester Western Springs Westmont Village of Westmont Stephen May Director of Public Woi (630) 981 -6271 smay @westmont.il.gov Nonel Nonega Wheaton City of Wheaton Paul Redman Director of Engineeri (630) 260 -2069 predman @wheaton.il us Michael Jankovic Wheaton SD Wheaton Sanitary Di Stephen Maney Executive Director (630) 668 -1515 maney@wsd.dst.il.us Sue Baert Winfield Wood Dale City of Wood Dale Brad Kittilson Wastewater Supervis (63 0) 787 -3782 bkittilson @wooddale com Woodridge Village of Woodridge Zill Khan Village Engineer (630) 7194755 zkhan @vil woodndge il.us Totals A 00.11 j'rA Stream Dissolvedo en � _ Improvement Feasibility XYg Study Salt Creek and East Branch of the Du General Project Description: The goal of this Stream Dissolved Oxygen Improvement Feasibility Study is to determine the feasibility and benefits of the removal or modification of dams, and of the construction and operation of in- stream aeration projects on improving dissolved oxygen in Salt Creek and the East Branch of the DuPage River. This study will identify specific projects that will help meet the Total Maximum Daily Loadings (TMDLs) goals for dissolved oxygen (DO) within the project area. The DuPage River / Salt Creek Work Group (DRSCW) is most interested in projects that will address the biological impairment in a holistic manner considering all benefits and costs to the ecosystem and surrounding community. This is the second newsletter created as part of this Feasibility Study. This newsletter focuses on the progress to date, including the Existing Stream Characteristics, Screening for Dams, Screening for Stream Aeration Technologies, and Water Quality Modeling. MCHENRY LAKE Mi _ n chiga-_ � r Salt Creek Watershed _ _ KANE 7 COOK East Branch DuPage River Watershed DUPAGE rl r , KENDALL Project Area Map Existing Stream Characteristics: Before evaluating alternatives for improving the DO on both the East Branch of the DuPage River and Salt Creek, it is important to understand the existing stream characteristics. Factors such as stream depth, plant canopy cover, sediment accumulation, stream bank erosion, riparian zone composition, wetlands, stream slope, and bank E C E 9.2 V.1-AGE OF OAX BROOK March _2006 East Branch DuPage River heights are all important during the development of alternative projects and the evaluation process. To aid in the understanding of the existing stream conditions, reconnaissance of both rivers was completed in October and November 2005. The field data was compiled into a GIS database. This database includes hyperlinks to project photographs, channel information forms (including channel cross sections), and habitat evaluation sheets. Both Salt Creek and the East Branch of the DuPage River are highly disturbed urban streams. All of the following characteristics contribute to the low DO concentrations: 6 Low channel gradients and elevation changes. 4. Channelization— ditching, dredging and straightening of channels - is extensive on both streams. Y Floodplains for the tributary streams and main channels have been developed, filled in and /or separated from the waterways, C Tributary drainage areas have a significant percentage of impervious areas, and stormwater runoff is directed into pipes that discharge directly into these waterways. Contributions from point sources, including municipal wastewater treatment plant effluents, are significant on both streams. e Plant canopy cover is generally limited due to adjacent development, resulting in higher summer stream temperatures and establishment of rooted vegetation. Artificial impoundments (dams, weirs, etc.) that limit rates of flow and allow accumulation of sediments and higher water temperatures. Screening for Stream Aeration Technologies: Numerous aeration technologies have been developed and utilized to increase DO concentrations in water. The study team evaluated this variety of available aeration technologies and identified a group of technologies that would be feasible for implementation in Salt Creek and the East Branch of the DuPage River. There are three major categories of technologies as follows. Air -Based Alternatives are designed to expose as much water volume as possible to the atmosphere in order to increase oxygen in the water. As water is exposed to the atmosphere, oxygen dissolves in the water. High - Purity Oxygen Alternatives are based on contacting the water column with a concentrated and pressurized source of oxygen. Specialized liquid oxygen vessels store the oxygen under pressure and utilize onsite vaporization to convert liquid oxygen to gaseous oxygen. Side - Stream Alternatives involve directing a portion of the total river flow off to the side and utilizing either air -based or high purity oxygen based technologies. The amount of water redirected is site dependent but typically ranges from 5% to 40% of the total flow. Critical categories for evaluating these technologies included the ability to increase DO to the state standard of 5.0 mg /L, navigation impacts and efficiency of transfer at shallow depths. Other criteria included the ability to increase DO concentration above saturation, construction complexity and costs, operation and maintenance issues, public concerns, and environmental impacts. In total, eight different categories were utilized to score each aeration technology. The following technologies represent the strongest candidates for enhancing DO given the conditions present in Salt Creek and the East Branch of the DuPage River: Air -Based Alternatives — fine bubble tubing. High- Purity Oxygen Alternatives — oxygen diffusers, U -tube aerators, aeration cones, low -head oxygenators, and sealed columns. Side - Stream Alternatives — side stream elevated pool aeration, pressure columns, side stream channel, and bubbleless aeration. In addition to the highest ranking technologies, there are several technologies that are moderate candidates for enhancing DO. These alternatives may be applicable only if very specific site and operational conditions are met. These conditions VC �1 nNC bumr Tuamr. RIVER amlg Fine bubble tubing example Typical liquid oxygen tanks include such things as space or elevation change or the need to apply alternatives in pools above dams. The alternatives most suitable for meeting the project objectives will be more closely evaluated on a site - specific basis in the next phase of the project. Side Stream Elevated Pool Aeration Examples Screening for Dams: Although a myriad of options exist for any given dam site, the three options being investigated for this study are: Complete Removal involves the removal of the entire dam structure. The picture on the left shows the Old Oak Brook Dam in its current condition, and the picture on the right shows how the stream would look if complete removal were to occur. Removal with Constructed Riffles involves removal of the entire dam structure followed by the construction of riffles to maintain a given upstream pool elevation. Partial 'Removal or Bridging involves constructing a ramp of large rocks up to the downstream face of the dam. Common variations may include partially lowering the dam crest to decrease the difference in vertical elevation or notching the crest to concentrate flow in the center of the channel. These options are being driven by the primary design objective of improving DO concentrations in the stream. A secondary design objective is to re- establish biological connectivity, mainly in the form of animal passage, at each dam site. Issues common to all dam modifications include permitting, reservoir sediment, and flood impacts. The permitting process for any of the three dam options will include federal, state and county requirements and. approvals. Next, reservoir sediments are typically the largest factor governing dam removal, because of the potential for contaminated sediments and movement to downstream areas. Finally, quantifying the flood impact of any modification to a dam is of utmost importance. Complete Removal Scenario - Old Oak Brook Dam Current and Future 'i L 1 ST FEW SV, i Sj PJ77N �. - -y- PLAN VIEW RIFFLE 51 FROM' CREST 20:1 Q SLOPE , BACNSLOPE SED PROFILE VIEW "T Removal with Constructed Riffles Dam Oak Meadows Dam Old Oak Brook Dam Fullersburg Woods Dam Churchill Woods Dam Prentiss Creek Dam Partial Removal or Bridging Removal Removal with Riffles Yes Yes Yes Yes Yes No Yes Yes Yes No Summary of Qualitative Screening of Dam Options The project may cause a positive or negative change in the floodplain boundary on adjacent properties. When comparing the three dam options, there are advantages and disadvantages of each when looking at specific locations. The project team Bridging - - - -- - Yes - - - -.- - ; -- Yes Yes No Yes conducted an initial qualitative analysis or screening of these options,, summarized in the above table. Additional quantitative evaluations will be conducted in the next step of the project to determine the water quality benefits and flood impacts associated with each of the "yes" alternatives. Water Quality Modeling: Since the TMDL reports were completed in October 2004,, the DRSCW has been working to better understand the causes of degraded water quality and, in particular, to find ways to improve DO concentrations in Salt Creek and the East Branch of the DuPage River. The main purpose of water quality modeling is to identify locations where low DO is expected or observed and quantitatively evaluate the effects of alternative projects (dam modifications and stream aeration) to potentially improve DO. The QUAL2E modeling tool used in the previous TMDL analysis has been updated with the current upgraded version of the same model called QUAL2K for this Feasibility Study. Simulations for both streams using the new model have returned results for dissolved oxygen and other water quality constituents consistent with the original model, as shown in the graph below. The QUAL2K model was then utilized to simulate actual conditions during the summer of 2005, representing critical conditions for low DO. Model parameters were established to represent the current physical and biochemical characteristics of Salt Creek and East Branch as determined from field investigations conducted as part of this study. Typical input data to this model includes water quality data, physical characteristics of the streams, chemical and biological reaction rates, light and heat information, and point source flow and water quality data. This modeling effort is still underway. 0 e 6 E6 2 Salt Cnwk Main Stem DD Comparison of QUAL2E K QUAL2K 32 30 26 26 24 22 20 16 16 14 12 10 a 5 t 2 0 615 bawd aMr MO.. -DUN1K -QUM2E r60Nr06) Public Workshop: The second public workshop is being held to continue the interaction between the stakeholders and the Feasibility Study team. The study team will provide an up- date .on this Feasibility Study at two different times as stated below. Presentations during this meeting will focus on water quality modeling, screening of dam modifications, and screening of stream aeration technologies. The public will be invited to identify their primary issues and concerns associated with this study. This meeting will be held as follows: Location Date College of DuPage March 9, 2006 Building K, Room 161 4:30 PM TO 6:30 PM 425 Fawell Blvd. OR Glen Ellyn, IL 60137 7:00 PM TO 9:00 PM Parking in Lots B &A For more information on the Feasibility Study or this meeting, please contact: Stephen McCracken T The Conservation Foundation 10 S 404 Knoch Knolls Road Naperville, IL 60565 1 Ph: (630) 768 7427 tlt \M Itt AIK/\ 11 ".l)tlltt\ Fax: (630) 428 4599 smccracken @theconservationfoundation.org Angela Dinkla HDR 8550 W Bryn Mawr Ave, Suite 900 Chicago, IL 60631 Ph: (773) 380 7946 Fax: (773) 380 7979 Angela.Dinkla @hdrinc.com Project Website: http : / /www.saitcreekeastbranch.com 401- K4f f, 911 AGENDA ITEM Regular Board of Trustees Meeting of June 9, 2009 SUBJECT: Salt Creek/Graue Mill Dam — IEPA Water Quality Item Total Maximum Daily Loads (TMDLs) x FROM: Dale L. Durfey, Jr., P.E., Village Engineer I. BUDGET SOURCE/BUDGET IMPACT: N.A. RECOMMENDED MOTION: Staff is seeking Board input. Background/History: At the Board meeting of May 19, 2009, Dennis Streicher and Stephen McCracken presented a brief history of the water quality issues on Salt Creek and the draft "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek" report. During discussion, additional information was requested and the issue was continued. The additional information is as follows: 1. The question of decreased property values. (Attachment 1) The Workgroup provided the attached paper entitled "Does Small Dam Removal Affect Local Property Values ?" dated July 2006 which concludes ". . . residential property located in the vicinity of a free - flowing stream is more valuable than identical property in the vicinity of a small impoundment, and that shoreline frontage along small impoundments confers no increase in residential property value compared to frontage along free - flowing streams." 2. The position of the Forest Preserve District which owns the property of the Graue Mill and Dam. (Attachment 2) Last saved by administrator J: \WORDDOC \TMDL P &BT 6 -9 -09 doc Last printed 6/5/2009 9:59 AM The attached letter from Ross Hill, Project Engineer, Forest Preserve District of DuPage County states "... Board of Commissioners has not taken any official stance with respect to possible modifications that have been suggested to the Graue Mill Dam" and "... any future consideration of dam modifications will require thorough deliberation and evaluation by our Commissioners... this issue is not yet ready to be brought to that decision - making level, and likely won't be brought to our Commissioners for serious discussions and consideration until the other three dam modification projects have been completed." 3. What permits would be needed. It appears that an Army Corps of Engineers permit, an IEPA permit, and an IDNR permit would be required. I have discussed with the Village Attorney if a Village of Oak Brook permit would be required, since the applicant would be the Forest Preserve District, another governmental body. The Village Attorney is reviewing the question but did state that the Village could not deny said permit if the application met the Village's Code requirements. 4. Better pictures showing the Mill. (Attachment 3) I'm told that the simulated pictures were not easily created but were first put together by their consultant in the first round of public meetings. The Workgroup has supplied the attached 2 pages of images (bridging and partial breach) that they do have. 5. Additional information on fish species. (Attachment 4) Information on fish species and Index of Biotic Integrity (IBI) scores are attached relating to testing on several dates above and below the dam. IBI scores indicate the diversity of species; higher numbers are better than lower. This is also discussed in section 2.9 of the "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek ". As part of Attachment 4 is a picture of a large northern pike caught on Salt Creek much closer to its confluence with the DesPlaines River. 6. A draft of the "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek ". (Attachment 5) The Workgroup will be reviewing the "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek" report at its June 24th meeting and voting to approve it. The Workgroup will be sending the final report to IEPA after June 24th since IEPA funded the study through a grant. The Workgroup will be adding recommendations to the report with the goal of apprising the IEPA of recommended mitigation options dealing with the dissolved oxygen impairment. Last saved by administrator J \WORDDOC \TMDL UBT 6 -9 -09 doc Last printed 6/5/2009 9 59 AM Staff is looking for direction from the Village Board regarding how it should vote regarding approval of the report at the Workgroup's June 24th meeting. The Village Board can: • Vote to support the report • Vote to be against the report • Take no position In any event, Oak Brook's position is advisory only. I understand that citizens may also want to speak at this meeting. Recommendation: That the Board provide direction to staff regarding how it should vote regarding approval of the report at the Workgroup's June 24th meeting. Last saved by administrator J: \WORDDOC \TMDL P &BT 6 -9 -09 doc Last printed 6/5/2009 9.59 AM University of Wisconsin - Madison Department of Agricultural &Applied Economics Staff Paper No. 501 July 2006 Does Small Dam Removal Affect Local Property Values? An Empirical Analysis A Bill Provencher, Helen Sarakinos and Tanya Meyer AGRICULTURAL & APPLIED ECONOMICS STAFF PAPER SERIES MAY 2 0 20-09 . F,r:E 0;- C,'' BFi,Gi( r1j, DEPART:`,' Copyright © 2006 Bill Provencher, Helen Sarakinos & Tanya Meyer. All rights reserved. Readers may make verbatim copies of this document for non - commercial purposes by any means, provided that this copyright notice appears on all such copies. Does Small Dam Removal Affect Local Property Values? An Empirical Analysis Bill Provencher Professor Department of Agricultural and Applied Economics University of Wisconsin — Madison Helen Sarakinos River Alliance of Wisconsin Tanya Meyer Department of Urban and Regional Planning University of Wisconsin — Madison July 2006 Abstract This paper uses hedonic analysis to examine the impact of small dam removal on property values in South - central Wiscosin. Data on residential property sales were obtained for three categories of sites: those where a dam is intact, those where a dam was recently removed, and those where the stream has been free - flowing for at least 20 years. The primary conclusions that emerge from the data are that residential property located in the vicinity of a free - flowing stream is more valuable than identical property in the vicinity of a small impoundment, and that shoreline frontage along small impoundments confers no increase in residential property value compared to frontage along free - flowing streams. I. Introduction It is estimated that more than 400 dams have been removed from US streams and rivers since the 1920s, with the majority of removals taking place after 1970 (Pohl, 2003). The decision to keep and repair a dam or to remove the structure and restore river habitat is necessarily a complex one that involves engineering, environmental, economic and social considerations. These decisions are frequently contentious, confounded not just by technical concerns but by social ones as well. A growing body of literature examines in detail many of the issues concerning dam removal (River Alliance of Wisconsin and Trout Unlimited, 2000; Gaylord Nelson Institute for Environmental Studies, 2001; American Rivers, 2002; H. John Heinz III Center, 2002; H. John Heinz III Center, 2003). One of the most vexing issues concerning dam removal is the impact on local property values. Frequently, property owners who view their property as "lake" frontage rather than river frontage fear that the valde of their property will decline with the loss of the dam and its associated impoundment (Born et al., 1998). To date, there has been no formal study of the effect of dam removal on local property values, and only a couple of informal examinations of this issue (Sarakinos and Johnson, 2003; Graber et al. 2001). The most common method for determining the effect on residential property values of a public project such as dam removal is hedonic analysis, which conceives of a residential property as a set of attributes including structural attributes such as square footage and number of bathrooms, and neighborhood characteristics such as crime rates and school quality. In the current context, the presence /absence of a dam, and the distance between a property and the impoundment, are hypothesized to be among the neighborhood attributes affecting property values. Hedonic analysis applies statistical techniques to market data to determine the relative contribution to property values of the various property attributes. This is the approach taken in the study of small dam removal presented here. The analysis includes market sales data over the period 1993 -2002 for three types of sites in south - central Wisconsin: those where a small dam remains intact, those where a small dam was recently removed, and those where a river or stream has been free - flowing for more than 20 years. Including all three types of sites allows us to separately identify the relative effect on property values of an intact small dam /impoundment. II. Data and Estimated Models Data Hedonic analysis of residential property requires that all properties used in the analysis are from a single residential market (see, for instance, Haab and McConnell, pg. 253). Defining the geographic boundaries of a housing market is of course a subjective matter. In our study we focus on the "Madison" housing market, defined as that portion of south - central Wisconsin within commuting distance of Madison, Wisconsin. The Madison market has seen a relatively large number of small dams removed since 1990. Figure 1 presents the locations of the fourteen sites in south - central Wisconsin used in the study. They are located in five counties and for our purposes are grouped into three categories: 1) six sites had dams removed during 1995 -2000 (hereafter called "removed" sites, 2) four had intact a a E m CO E (D 0 > 0 E N c0 i ti W CL o C co 0 o sm Cl) cn kkwi LL �Mlr EVIP a a E m CO E (D 0 > 0 E N c0 i ti W CL o C co 0 o sm Cl) cn kkwi LL dams during the study period ( "intact" sites), and 3) four have free - flowing river sections passing through the municipality ( "free- flowing" sites). Free - flowing sites have either never had a dam, or if they did, the dam was removed at least 20 years ago. Table 1 contains a brief overview of the study sites. All sites are comprised predominantly of year -round residential properties rather than vacation homes. All are located in small municipalities. Six of the sites can be categorized as former mill towns, in the sense that a commercial /industrial district developed along the millpond formed by the dam, with the older residential district typically '/4 -mile or more away from the river. At the remaining four removed /intact sites the waterfront is dominated by residential, rather than commercial /industrial, properties. Virtually all of the sites have open space or park lands along some portion of the waterfront. The village of Baraboo has three sites in the study; an upriver free - flowing site, and two downstream removed sites. Table 2 provides stream and impoundment characteristics. All existing and former impoundments in the study can be categorized as small, given their range of surface areas (8 to 194 acres), and range of maximum depths (5 to 15 feet). In none of the impoundments is the water especially clear in midsummer; secchi depths range from 1.5 to 2.4 feet. The two largest impoundments, Belleville and Marshall, are both intact dam sites. The unit of observation in the study is a single- family residential property within '/4 mile of a study site water body. For removed and intact sites, observations are within a '/4 mile of the existing or former impoundment, or within '/4 mile of the first mile of stream below the dam. For free - flowing sites, observations are within '/4 mile of a two -mile stretch of the stream. Observations were limited to parcels of one acre or less, to minimize the confounding effects in the hedonic analysis of future development potential. The single- market requirement of hedonic analysis is temporal as well as spatial; a house sold in 1950 is not in the same market as one sold in 2000. Yet as with any statistical analysis, the more observations the better, and this consideration advocates for stretching the time frame of the analysis. Moreover, there is considerable information to be gained form collecting observations before and after dam removal at removed sites. The time frame in our study is 1993 -2002, which provided us with both adequate sales data and good temporal bracketing of dam removal at removed sites (see Table 1 for dam removal dates). To accommodate temporal shifts in the residential property market over the study period, we included annual dummy variables in the hedonic analysis. To avoid conflating the immediate effect of dam removal with the longer -term changes in property values associated with the evolution of the riparian zone to a free - flowing stream, observations at removed sites were collected only for the 5 -year period centered on the year the dam was removed. So, for instance, data at the Token Creek site were collected only for the period 1997 -2001. In total, 773 observations were used in the analysis, of which 116 were frontage parcels and 657 were nonfrontage parcels. Table 3 provides a breakdown of the observations for each study site. The most obvious weakness of the data is the lack of frontage observations at removed sites. As discussed shortly, this impacted the hedonic analysis we were able to conduct. All variables used in the estimation are for the year of sale. The data were typically found through Geographic Information Systems (GIS), GIS webviewer applications, hard copy maps, deeds, and tax rolls. The set of observations includes only "arm's length" transactions (sales between unrelated parties). Many waterfront sales were not admissible because they were either family exchanges (non -arm's length sales), or the grantee was the village or town. 1 Table 1. Overview of Study Sites Site No. Dam Name Site Type Removal Date Municipality Population 2 County 1 Rockdale Removed Dam June 2000 Rockdale 214 Dane 2 Token Creek Removed Dam Dec 1999 N/A' N/A Dane 3 Oak Street Removed Dam Dec 2000 Baraboo 10,711 Sauk 4 Waterworks Removed Dam Dec 1998 Baraboo 10,711 Sauk 5 LaValle Removed Dam Oct 2000 LaValle 326 Sauk 6 Hebron Removed Dam Aug 1996 Hebron 4 243 Jefferson 7 Belleville Intact Dam N/A Belleville 1,908 Dane 8 Marshall Intact Dam N/A Marshall 3,432 Dane 9 Ball Park Intact Dam N/A Waterloo 3,259 Jefferson 10 Udeys Intact Dam N/A Columbus 4,479 Columbia & Creek 3 Oak Street Dodge 11 Black Earth Freeflowing Stream 1957 Black Earth 1,320 Dane 12 Island Woolen Freeflowing Stream 1972 Baraboo 10,711 Sauk Mill 13 Reedsburg Freeflowing Stream 1973 Reedsburg 7,827 Sauk Dam 14 N/A Freeflowing Stream N/A DeForest 7,368 Dane ' Source: Wisconsin Department of Natural Resources Dams Safety Program Database 01/2006 2 Source: U.S. Census Bureau, Census 2000 3 Cluster of residences located within Towns of Burke and Windsor 4 Per Census 2000, Hebron designated as a statistical entity comprising a densely settled concentration of population that is not within an incorporated place, but is locally identified by a name. Table 2. River and Impoundment Characteristics Site Dam Name Impound Impound Impoundment Secchi Stream Waters Mean Monthly No. ment ment Max Depth 1 Depth 2 hed Discharge Surface Normal (ft) (ft) Basin (Min -Max) Area 1 Storage (cfs) (acres) (acre -ft) 1 Rockdale 104 170 5 2.2 Koshkonog Lower Rock 45.3-1693 Creek 2 Token 23 50 6 2.3 Token Lower Rock 18.5-32.8 4 Creek Creek 3 Oak Street 16 60 7 N/A Baraboo Lower 248-798 5 1 In this latter case the parcel became tax - exempt, and so court records no longer included data on the value of improvements; such data were necessary for our analysis). 1 Table 3. Observations Tally Site No. River Wisconsin Site Type 4 Waterworks 47 190 12 N/A Baraboo Lower 248 - 798 5 Rockdale River Wisconsin 2 5 LaValle 21 60 6 2.2 Baraboo Lower 248-798 5 Token Creek River Wisconsin 27 6 Hebron 28 100 15 2.5 Bark River Lower Rock 649-144 6 7 Belleville 112 260 7 1.5 Sugar River Sugar- 85-222 7 4 Waterworks Pecatonica Removed Dam 8 Marshall 194 320 15 2.4 Maunesha Upper Rock N/A LaValle River Removed Dam 0 9 Ball Park 8 15 5 2.4 Maunesha Upper Rock N/A Bark River River 0 2 10 Udeys 26 90 10 N/A Crawfish Upper Rock 18-105 8 Intact Dam River 56 67 11 Black Earth N/A N/A N/A N/A Black Earth Lower 293-47.6 9 39 Creek Wisconsin 9 12 Island N/A N/A N/A N/A Baraboo Lower 248-798 5 Woolen Mill River Wisconsin Udeys 13 Reedsburg N/A N/A N/A N/A Baraboo Lower 248-798 5 Dam River Wisconsin Black Earth Creek 14 N/A N/A N/A N/A N/A Yahara Lower Rock 159-37.6 10 River 1 Source: Wisconsin Department of Natural Resources Dams Safety Program Database 01/2006 2 Source: University of Wisconsin- Madison, Environmental Remote Sensing Center, www.landsat.org • 3 Source: nearest inactive USGS Gaging Station 05427507, Koshkonong Creek, near Rockdale, WI (period of record 11/01/76-10/21/82) 4 Source: nearest inactive USGS Gaging Station 05427800, Token Creek near Madison, WI (period of record: 07/28/64- 12/31 /80) 5 Source: nearest active USGS Gaging Station 05405000, Baraboo, WI s Source: nearest USGS active Gaging Station 05426250, Rome, WI ' Estimated flows at Hwy 69 Bridge in Belleville, WI based on data from active USGS gaging station 05436500 Source. "Definite Project Report with Integrated Environmental Assessment. Public Review Draft ", Army Corps of Engineers, June 2003 8 Source: Inspection and Evaluation Study (Final): Udey Dam, Mead & Hunt, September 2005 9 Source: nearest active USGS Gaging Station 05406500, Black Earth, WI 10 Source: nearest active USGS Gaging Station 05427718, Windsor, WI Table 3. Observations Tally Site No. Dam Name Stream Site Type Frontage Observati ons Nonfront age Observa tions Total Observa tions 1 Rockdale Koshkonog Creek Removed Dam 2 14 16 2 Token Creek Token Creek Removed Dam 0 27 27 3 Oak Street Baraboo River Removed Dam 4 42 46 4 Waterworks Baraboo River Removed Dam 0 42 42 5 LaValle Baraboo River Removed Dam 0 41 41 6 Hebron Bark River Removed Dam 0 2 2 7 Belleville Sugar River Intact Dam 11 56 67 8 Marshall Maunesha River Intact Dam 39 113 152 9 Ball Park Maunesha River Intact Dam 5 56 61 10 Udeys Crawfish River Intact Dam 12 62 74 11 Black Earth Black Earth Creek Freeflowing Stream 0 56 56 12 Island Woolen Mill Baraboo River Freeflowing Stream 11 52 63 13 Reedsburg Dam Baraboo River Freeflowing Stream 2 29 31 14 N/A Yahara River Freeflowing Stream 30 65 95 Total Observations Used in Analysis 116 657 773 Form of the Hedonic Price Function The underlying premise of the hedonic price function is that a residential property is a collection of attributes, each with an implicit price. Rosen (l 974) is the classic reference, and Freeman (1993) provides a good discussion. The dependent variable in the hedonic model is the sale price of the property. Following Papenfus and Provencher (2006), we do not include features of the residential structure, such as square footage and the number of bedrooms, as explanatory variables, but instead include as an explanatory variable the assessed value of improvements to the land as a proxy for the value of the residential structure and other improvements. The underlying perspective of this approach is that assessors accurately judge the value of improvements, up to a factor of proportionality to be estimated in the model. As explicitly assumed in tax assessments, we treat the market value of residential property as the sum of the value of land and improvements. Letting f (x) denote a parcel's land value, where x is a vector of parcel characteristics, and letting IMPROVE denote the assessed value of improvements on the parcel at the time of sale, we have the hedonic form, P = f (x) +a- IMPROVE +E (1) where a is the factor of proportionality to be estimated, and E is a random component accounting for unobserved variability in residential property prices. In preliminary estimation, we tried several forms for the land value function f (x) ; all of them gave qualitatively similar results. A simple linear form is problematic, as it assumes that the marginal value of an increase in a property characteristic is constant and unrelated to the values of other characteristics, though quadratic and interaction terms can be added to capture important nonlinearities. An alternative model is one in which f (x) takes an exponential form, (f (x) = e, x ). We report results for two models, one where f (x) is linear and the other where it is exponential. Brief Discussion of Variables Affecting Property Values Table 4 provides definitions for the vector x used in estimation. Table 5 provides means and standard deviations for a selected set of these variables. Here we discuss the variables that bear immediately on the question of the effect of dam removal on residential property prices. Dummy variables distinguish the state of sites at the time of a property sale. FREEFLOW takes a value of 1 if a site is a free - flowing site, and 0 otherwise. INTACT takes a value of l if a dam was intact at the site at the time of sale, and 0 otherwise. Clearly, all observations at intact sites take a value of 1 for this variable, and importantly, so too do observations at removed sites if the sale took place before the dam was removed (recall that the set of observations at removed sites includes sales made both before and after dam removal). This leaves a third category of observations —those made at removed sites in the two years following dam removal —that serves as a baseline reference category in the estimation of the hedonic price function. We include two variables used to capture the effect of shoreline frontage across all sites (FRONTDUM, LNFRONT), and two dummy variables to examine the particular effect of frontage in the presence of a dam: INTACT -FRONT applies to the subset of INTACT properties with shoreline frontage, and INTACTUP applies to the subset of such properties with shoreline frontage upstream from the dam.2 Note that we do not include a dummy variable analogous to INTACT for shoreline frontage at free - flowing sites. If we included such a variable, the baseline for comparison among shoreline properties would be shoreline properties sold after removal of a dam, yet we have only six such properties in our sample —far too few to provide a reliable point of comparison.3 Consequently, the coefficients on INTACT -FRONT and INTACTUP are effectively the premiums fetched by shoreline frontage in the presence of an intact dam compared to shoreline frontage along a free - flowing stream. Table 4. Variables Used in the Hedonic Models Variable Definition PRICE Sale price in 2005 dollars C Intercept term H2ODIST Distance from the property to the water body, in feet FRONTDUM Dummy variable taking a value of 1 if the property has water frontage LNFRONT Natural Log of frontage, in feet DISTMSN Distance from the site to Madison, in miles DISTMKE Distance from the site to Milwaukee, in miles LNLOTSIZE Natural log of the lot (parcel) size, in acres INTACT Dummy variable taking a value of 1 if the site had an intact dam at the time of sale INTACT -FRONT Interaction between FRONTDUM and INTACT INTACTUP Dummy interaction between INTACT -FRONT and a dummy variable taking a value of 1 if the property is located upstream of the dam FREEFLOW Dummy variable taking a value of 1 if the site is a free - flowing site (see text) TSALE Year of sale index, with 1992 =0, 1993 =1, etc. IMPROVE Assessed value of the improvement in the year of sale, in 2005 dollars Table 5. Descriptive Statistics for Selected Variables Variable Mean Standard Deviation PRICE 112,247 59,093 H2ODIST 642.1 463.5 FRONTDUM 0.1500 .3574 FRONT (conditional on >0) 114.9 50.60 DISTMSN 29.14 15.63 DISTMKE 93.16 2571 LOTSIZE 0.3251 01857 2 Recall that the sample includes sales downstream of the dam. 3 By comparison, our sample includes 65 frontage properties where the dam is intact at the time of sale, and 45 frontage properties at free - flowing sites. INTACT 0.5783 0.4942 IMPROVE 69,399 46,218 III. Estimation results Estimation results are presented in Table 6. The first model is linear in parameters, and the second model, which hereafter we refer to as the exponential model, is separable in land and improvements, with the value of land captured by an exponential term, as described previously. We initially focus on results for the linear model, and then turn to the question of whether results from the exponential model are substantially different than those from the linear model. Linear Model The coefficient on IMPROVE is the factor of proportionality that corrects for systematic bias in assessments of residential structures (Equation (1)). When this factor equals 1, the assessment accurately captures the value of improvements, on average. A value greater than 1 indicates a systematic underassessment, and a value less than I indicates a systematic overassessment. Estimation results indicate that on average structural improvements are over - assessed by about 22 %, though this does not imply that the property itself is over - assessed (the land may be typically under - assessed). The coefficient on TSALE indicates that each year the value of land in the study increased by $1947 on average. Distance to Madison reduces the value of property at the rate of $823 per mile, and distance to Milwaukee reduces the value of property at a rate of $233 per mile. Together, these results indicate that all else equal, a property that lies 30 miles outside of Madison, but directly towards Milwaukee, has a value $17,700 less than an identical property in Madison, while a property that lies 30 miles outside of Madison, and directly away from Milwaukee, has a value $31,680 less than an identical property in Madison. The coefficient on LNLOTSIZE indicates that increasing lot size from '/4 acre to '/2 acre increases the value of a property by $12,580. The positive sign on H2ODIST, and the nonsignificance of FRONTDUM and LNFRONT, conflict with the intuition of most observers that a location on or near a body of water confers a price premium. Yet the literature is actually mixed on the effect of distance to water on household welfare. Consistent with intuition is the analysis of Stumborg et al. (2001), who find that distance to a large lake (Lake Mendota in Madison, Wisconsin) has a negative effect on household willingness to pay for reductions of phosphorus loading of the lake, presumably because households closest to the lake value improvements to the lake most highly. Moore et al. (2006) find a similar result for Green Bay, Wisconsin. In a hedonic examination of property values in the vicinity of Lake Austin, a 1600 acre reservoir on the Colorado River in Austin, Texas, Lansford and Jones (1995) also find that distance to the reservoir has a negative effect on property values. By contrast, Chattapodhyay et al. (2005) find that property values rise with distance from Waukegon Harbor, a Superfund site on Lake Michigan. Perhaps the most interesting results related to the current study are those obtained by Mahan et al. (2000). The authors find that the effect of the distance of a residence to a wetland depends on the wetland type (open vs. forest vs. scrub -shrub vs. emergent) and shape (linear, such as along a stream, vs. a polygonic "areal" shape). The authors find, for instance, that property values fall with distance to an areal open wetland, but rise with distance to a linear open wetland. Bin (2005) finds that proximity to an open wetland has a positive effect on property value, while proximity to three other types of wetlands —the same types used in Mahan et al —has a negative effect on property values. In light of the available literature, there are two plausible explanations for the results concerning H2ODIST, FRONTDUM, and LNFRONT. The first is that these results simply reflect the dominance of negative effects associated with proximity to the types of water bodies in our study. Such effects include the risk of flood damage, perennial damage issues such as water seepage into basements, mosquito infestations on impoundments, foul odors associated with algae blooms and decaying vegetation, and so on, as well as effects arising from legal restrictions on the use of land near waterways, some of which are imposed to mitigate the above - mentioned negative effects, such as rules concerning housing construction on flood plains, or rules to reduce eutrophication of an impoundment. It is worth emphasizing that many of the reservoirs formed by impoundments at the study sites are quite small and shallow (Table 2). An alternative explanation is that the model is misspecified. In particular, because the commercial district is adjacent to the waterway at a number of the study sites —many of the impoundments were originally created in the service of a mill, and historically these mills anchored a village's commerce —the effects on property value of H2ODIST, FRONTDUM, and LNFRONT are confounded by their collinearity with the distance between the residence and the commercial district, a relationship that we do not include in the model. One might expect that the greater the distance between a residential property and the village's commercial district, the higher the property price, at least in the range of the distances covered by our data (all properties are within a quarter -mile of the waterway). If this is the case, the positive sign on H2ODIST, and the nonsignificance of FRONTDUM and LNFRONT, may reflect the confounding influence of proximity to the commercial district. To explore this possibility, we developed a dummy variable for those sites where the commercial district was clearly not along the waterway, and then re- estimated the models (linear and exponential) with interactions between the dummy variable and the variables H2ODIST, FRONTDUM, and LNFRONT.4 In neither of these amended models were the interactions statistically significant, either alone or as a group, lending some measure of support to the conclusion that the results reported in Table 3 are "real ". At the very least, the results raise doubts that the value of shoreline property along small impoundments and streams in the study area is much higher than neighboring property. The result for the variable INTACT indicates that a property within a quarter mile of an impoundment is no more valuable than a similar property at a site where a dam was recently removed. By comparison, the statistically significant coefficient on FREEFLOW, along with the nonsignificance of INTACT, indicates that a property within a quarter mile of a free - flowing river is worth roughly $13,700 more than a similar property at a site of a recently removed or current impoundment. 4 The sites identified as having no (or very little) commercial property along the waterway were Black Earth, Deforest, Island Woolen, Marshall, and Token Creek. Finally, the coefficients on INTACT -FRONT and INTACTUP are not statistically significant, indicating that holding frontage at an impoundment confers no price premium relative to holding frontage along a free - flowing river. Exponential Model The exponential model generates results qualitatively similar to those found for the linear model. The coefficient on IMPROVE is nearly identical to that in the linear model. The coefficient on LNLOTSIZE has the expected sign, and indicates that increasing a lot from '/4 acre to %2 acre increases the land value of property (that is, the value of the property net the value of the structure) by about 16 %. At the estimated median land value in the sample ($35,900), this is an increase of $5744. The coefficient on TSALE indicates that residential land values rise at 3.9% per year after inflation ($1400 at the median price). As in the linear model, H2ODIST has a positive effect on property prices. In this model, increasing the distance to shoreline from >0 (just off the shore) to 1/8 mile increases the value of land by 10.8 %, or $3880 at the sample median land price. The biggest difference between this model and the linear model is the statistically significant effect of frontage on land price, as indicated by the statistical significance of the coefficients on FRONTDUM and LNLOTSIZE, though the practical effect of frontage would appear to be generally small, and counterintuitive at the margin. A property with a median amount of frontage (118 feet) is 3.9% more valuable than a similar property without any frontage ($1390 at the median land price). Yet in the range of the data the predicted marginal effect of frontage is actually negative; the model predicts that properties with 81 feet of frontage (the 25th percentile of frontage properties) are 12.3% more valuable than properties without frontage, while properties with 136 feet of frontage (the 75th percentile of frontage properties) are only 0.9% more valuable. As with the linear model, this model provides evidence that a free - flowing river adds value to a nearby property (a property within '/4 mile) compared to the baseline (that is, a property sold after removal of a nearby dam). The median property is worth $13,900 more at a FREEFLOW site. On the other hand —and again, as with the linear model —the model provides no statistical evidence that residential property in the vicinity of an existing impoundment adds value to a property compared to the baseline scenario (INTACT is not statistically significant). Nor is there statistical evidence that frontage property in the vicinity of a small dam is more valuable than frontage property on a free - flowing river (INTACT -FRONT and INTACTUP are not statistically significant, either together or individually). Table 6. Estimation Results Variable Linear Model Exponential Model Coefficient Standard Coefficient Estimate Standard Error Estimate Error C 104,750. ** 10,140. 11.774 ** 0.2103 H2ODIST 8.5776 ** 3.176 1.5567 .10 -4 * 0.773010 "4 FRONTDUM 39,024. 36,890. 1.0303 ** 0.36164 LNFRONT - 7188.1 7435. - .20798+ .07474 DISTMSN - 822.77 ** 113.6 - 2.0106.10 -2 0.3449.10-2 DISTMKE - 232.89 ** 75.37 - 4.3767.10-3 1.82610-3 LNLOTSIZE 18,151 ** 2979. .31718 ** 0.04782 INTACT - 1043.0 3419. 4.580710-2 9.379.10-2 INTACT -FRONT - 5620.4 12,840. 4.4254.10 -2 30.1210-2 INTACTUP - 400.92 10,980. - 5.4786.10 "2 30.2710-2 FREEFLOW 13,733. ** 4194. 0.32696 ** 0.09635 TSALE 1947.0 ** 606.0 3.9378-1 0-2 0.8469.10-2 IMPROVE 0.78650 ** 0.05283 0.78724 ** 0.03056 * Signifcant at .05 level; ** Significant at .01 level IV. Discussion The general conclusion that emerges from the data is that shoreline frontage along small impoundments confers no noticeable increase in residential property price compared to frontage along free - flowing rivers, and that residential property located in the vicinity of a free - flowing river is more valuable than identical property located in the vicinity of an impoundment. Moreover, although the analysis is cross - sectional, the results are consistent with the conclusion that removing a dam does little harm to property values in the short run (2 years in the study), and serves to increase property values in the long run, as the stream and associated riparian zone matures to a "natural" free - flowing state, or is managed as a desirable open space. Some caution is necessary in interpreting the results. The conclusion that free - flowing rivers confer a price premium on residential property compared to impounded waters is likely due to the small size of the impoundments at our study sites. The conclusion should not be extended to large impoundments where such activities as fishing, boating, and swimming are especially attractive. Still, the study results are consistent with other available evidence concerning the restoration of trout streams in Wisconsin. An informal study by Wagner (2001) found that after dam removal riparian property values either remained unchanged, or dropped temporarily and rebounded within two years. Sarakinos and Johnson (2003) report that when the Ward Dam was removed from the Prairie River in Merrill, WI, three homes that were put up for sale before the removal received their pre - removal asking price, with two of the homes purchased by buyers eager to have frontage on a restored trout stream. We focused attention on a relatively small geographic region because hedonic analysis requires analysis of a single housing market. Nonetheless, we would argue that the general nature of these results apply broadly. To argue otherwise is to argue either or both of two points, one on the demand -side, the other on the supply -side. The demand -side argument is that in other regions the population is more likely to prefer small impoundments over free - flowing rivers, which, given population mobility, implies that individuals choose their regional location based at least partly on this preference ordering. This seems unlikely. The supply -side argument is that the relative abundance of housing in the vicinity of free - flowing rivers compared to housing in the vicinity of impoundments is greater in other regions than in the study area. This would serve to make housing in the vicinity of an impoundment a relatively scarce and thus more valuable commodity. It is important to keep in mind that economic values generated from hedonic analysis reflect only those benefits and costs that are capitalized in land values. Some of the economic value (both positive and negative) associated with dam removal is not capitalized. For instance, the benefits to nonresidents who visit an impoundment for fishing and swimming will not be reflected in local land values. Similarly, the benefits to nonresidents associated with restoring a stream, such as improved trout fishing, will not be captured in a hedonic analysis. Estimating such values requires an alternative technique, such as contingent valuation. An important question that the analysis does not completely illuminate is the effect of dam removal on shoreline properties. If these properties retain their frontage, then the results indicate that at least in the long run (after the waterway gains the appearance of a "free- flowing" stream) there is no frontage - specific significant chan e in property price, except for the increase associated with the expansion of the lot size. If these properties lose their frontage as the impoundment waters recede to the original contours of the stream, then the relevant issue is what occupies the land formerly submerged in water. A typical outcome is that a riverside public "greenbelt" replaces the impoundment. Studies generally indicate that open space increases the housing values of adjacent properties, though the effect ultimately depends on the exact nature of the open space; it appears that open space dedicated to nature preservation and "passive experiences" such as hiking and bird - watching is most likely to have a significant positive impact on the value of bordering properties.6 This being the case, and given the results of the current study, the available evidence is that properties that lose their frontage on impoundments would increase in value as their frontage converts to "frontage" on a riverside greenbelt, so long as the greenbelt is dedicated to preserving the natural features of the riparian zone. 5 There is, as discussed previously, a general increase in property price that accrues to all properties, nonfrontage and frontage alike. 6 Correl et al. (1978) found that properties rose with proximity to greenbelts in Boulder, Colorado, though it bears mention that the authors did not include a dummy variable to account for sharing a property boundary with the greenbelt. Do and Grudnitski (1995) find that homes abutting a golf course experience an increase in sale price of 7.6 %. Lutenhiser and Netusil (2001) find that properties in Portland, Oregon "adjacent" to open space (within 200 feet) were more valuable than those further away, with this price effect being greatest for golf courses and natural area parks (those parks designed to preserve natural habitat and provide resource -based activities, such as walking and bird - watching), and smallest for urban parks (those parks managed primarily for "nonnatural" recreation, such as ball fields and tennis courts). 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Staff paper, Department of Agricultural and Applied Economics, University of Wisconsin, 2006. Pohl, Molly M. "American dam removal census: Available data and data needs ". Dam Removal Research: Status and Prospects. William L. Graf (editor). Washington, DC: The H. John Heinz III Center for Science, Economics and the Environment. Proceedings of The Heinz Center's Dam Removal Research Workshop, October 23 -23, 2002. 2003. River Alliance of Wisconsin and Trout Unlimited. "Dam removal: A citizen's guide to restoring rivers ". Madison, WI. 2000. Rosen, S. " Hedonic prices and implicit markets: product differentiation in perfect competition ", Journal of Political Economy, 82(l), 1974: 34 -55. Sarakinos, Helen and S.E. Johnson. "Social perspectives on dam removal ". Dam Removal Research: Status and Prospects. William L. Graf (editor). Washington, DC: The H. John Heinz III Center for Science, Economics and the Environment. Proceedings of The Heinz Center's Dam Removal Research Workshop, October 23 -23, 2002. 2003. Stumborg, Basil E, Kenneth A. Baerenklau, and Richard C. Bishop. "Nonpoint Source Pollution and Present Values: A Contingent Valuation Study of Lake Mendota ". Review of Agricultural Economics, v. 23 (1), 2001: 120 -32. Wagner, Carmen. "Fiscal impacts of dam removals ". Unpublished paper prepared for Urban and Regional Planning 751: Introduction to Financial Planning. University of Wisconsin - Madison. May 2001. Weicher, J.C., and R.H. Zerbst. "The externalities of neighborhood parks: an empirical investigation ". Land Economics 49(1), 1973: 99 -105. May 28, 2009 Mr. Dale L. Durfey, Jr., P.E. Village Engineer Village of Oak Brook 1200 Oak Brook Road Oak Brook, EL 60523 ;�� I`r;��' it s -f JUN i V;LL "GF OF 0 'D., 0K Ef1GIi:ELRiNG DEP, %1"TM,INT RE: SALT CREEK WATER QUALITY STUDIES AND GRADE MILL DAM FULLERSBURG WOODS PROJECT FILE Z- 123 -006 Dear Dale: Thank you for your telephone call regarding the "Stream Dissolved Oxygen Improvement Feasibility Study for Salt Creek," which is currently being prepared by the DuPage River Salt Creek Workgroup. I am aware that the Workgroup made a pair of presentations regarding this study to the general public at the Oak Brook Village Hall on March 18"' and March 31", and I was able to attend the latter meeting. Please be aware that the Forest Preserve District's Board of Commissioners has not taken any official stance' with respect to possible modifications that have been suggested to the Graue Mill Dam at Fullersburg Woods. You may be aware that the District has several other dam modification projects that are currently in various- stages of design, permitting and partial completion, including McDowell Grove Dam and Warrenville Grove Dam on the West Branch of the DuPage River, and Churchill Woods Lagoon Dam on the East Branch of the DuPage River. It will likely be several years down the road before these three other dam removal projects are complete, and we can see demonstrable results with respect to the anticipated benefits to water quality and aquatic habitat. Given the acknowledged historic significance of the Graue Mill Dam, and the importance of the dam to iT'iaily 'oval is SldeiitS and histOlit: �Jlesei-Vationists /as evidenced by the opiiliUrls expressed at the recent public meetings in March), any future consideration of dam modifications will require thorough deliberation and evaluation by our Commissioners. From the staff perspective, this issue is not yet ready to be brought to that decision - making level, and likely won't brought to our Commissioners for serious discussions and consideration until the other three dam modification projects have been completed. If you have any questions or need any additional information at this time, please do not hesitate to contact me directly by telephone at (630) 933 -7244. Since ly, Ross A. Hill, P.E. ` Project Engineer = 0912004RAH.doc ` Mailing Address: P.O. Box 5000 - Wheaton, IL 60189 -5000 - www.dupageforest.com k Yi (� tov r . • =_=4k ^°r" mi�A ,•4li j� 4r'fiJ y l i ( '•.ao3 > R }) I i ! t j, it IV,' V x r •R�, (.y� s7% s ��y'{ ' zj �•"t1 I�•♦ � r 3 �1` i�� b �a q i Av.�,v t £� t J ' t •' 1 r I r • R9a r 14 4 - 4 t U X-1 771, '4r 10- CL V H C4 M- 0) V V *a • • • CD E E E C) 13 0 Fish Species and IBI score details. Salt Creek River Miles (RM) S -12.5 iRed — Above darn` 41, Q7 V : tt-too - svil i;', fail. R kv, tr Dot sm v coy, F seat hod"I'-w i V : tt-too - svil i;', fail. R kv, Not t� too 1• iii I Ton IV CA 8C 95 -850 - Salt Creek; Date: 08-03 RM__ 11.00 'point Common name 5 Black crape e 85 Bluegill'' 57 Bluntnose minnow, 16 Black_ stri a to minnow 'b Carp; 1 Carp x Goldfish hybrid 8 Golden shiner 33 Green sunfish Il Gizzard shad 13 Largemouth bass 86 Orangespotted sun I Yellow bullhead �l Yellow perch 313 Total individuals Metric Score Metric description 11 2 Native fish species 2 2 Native minnow species 0 0 Native sucker species 5 5 Native sunfish species 0 0 Benthic invertivore species' 0 0 Intolerant species 0.000 0 Prop specialist benthic inv_erti_v_ores' 0.613 5 Prop geneneralist feeders 0.000 0 Prop mineral- substrate spayners 0.455 4 Prop tolerant species�� 18 Of SC 95 -850 -Salt Creek; Date: 09-29-2007, RM _ l l .00 Count Common name I8 Black crappie; 70_ Bluegill' 11 Bluntnose minnowL_ 19 Blackstripe topminnow 17 Carp 2 Carp x Goldfish hybrid 11 Golden shine 7 Green sunfish 21 20 Gizzard shad Largemouth bass 33 4rangespotted sunfish 1 Unidentified Sunfish hybri 17 Spotfin shiner 11 White sucker, 242 Total individuals Metric Score Metric descri ption 12 2 Native fish species 3 2 Dative minnow species 1 1 Native sucker species 5 6 Native sunfish species, D 0 Benthic invertivore species D 0 Intolerant species; D.000 0 Prop specialist benthic invertivores D.649 5 Prop geneneralist feeders`, D.000 0 Prop mineral-substrate_ spawners D.417 4 Prop tolerant species( 20 IBIS SC 95 -850 - Salt Creek; Date _08 -04 -2007; RM:___ 12.50 Count Common name 2 Black crappie 110 Bluegill 23 Bluntnose minnow �4 Blackstripe topmmnow 11 Carp,-� _ - -- 1 Carp x Goldfish hybrid -- 11 Green sunfish - 5 Gizzard shad 18 Largemouth bass '8 Drangespotted sunfish 2 Unidentified Sunfish hybrid 2 White sucker 2 Yellow bullhead 89 Total individuals 'Metric Score Metric description M_r-_.,..- 10 __2� Native-fish species t I Native minnow species l I Native sucker species > 5 Native sunfish species; 1 0 Benthic invertivore species 4 0 Intolerant species ).000 0 Prop specialist benthic invertivores ).730 4 Pr(ip gen €neralist feeders ).000 0 Prop mineral- substrate spawners, ).500 4 Prop_tolerant species` 0 17 IBI, SC 95 -850 - Salt Creek; Date: 09 -30 -2007; RM: 12.50; Count Common name Black bullhead 0 Bluegill! 5 Bluntnose minnow 9 Blackstripe topminnow, Bigmouth shiner; -- 7 Carp: Carp x Goldfish hybrid Green sunfish, Gizzard shad Largemouth bass �� 7 Orangespotted sunfish Unidentified Sunfish hybrid Spotfin shiner] White suckeri Yellow bullhead Yellow bass) 19 Total _ individu - uteals Metric Score Metric description, 13 3 Native fish speciesL. 3 2 Native minnow. species; 1 1 Native sucker species 4 4 Native sunfish species 1 1 Benthic invertivore spec).esl 0 0 Intolerant species 0.000 0 Prop specialist benthic invertivores 0.605 5 Prop geneneralist feeders' 0.000 0 Prop mineral- substrate spawners, 0.385 4 Prop tolerant speciesj 20 IBIS Notes; High IBIs are desirable. Intolerant species, benthic invertivores and mineral substrate spawners are totally absent from the stations above the dam. Specie diversity declines and generalist/tolerant species become dominate. These are clear indicators of serious water quality and habitat impairment. Certain species, spotted sucker, channel catfish and northern pike are only found in the watershed, downstream of the dam. C' a •, �� wl � t J ��i ,, j .. S•tz t, ` r k }I' s �^ , {7i.. '(1Sr�'" ` y= h'•o fi .e Cam"` r`� * lie l �� cr 3 DuPAGE RIVER/SALT CREEK WORK GROUP STREAM DISSOLVED OXYGEN IMPROVEMENT FEASIBILITY STUDY FOR SALT CREEK Prepared by: DRAFT FINAL REPORT JUNE 2009 HDR Engineering, Inc. 8550 W. Bryn Mawr Ave., Suite 900 Chicago, IL 60603 Job No. 31566 In Association With: All A&Vhhhh' inter-fluve., inc. DO Improvement Feasibility Study Salt Creek 1.0 Project Background and Goals 1 PROJECT BACKGROUND AND GOALS The 2000 National Water Quality Inventory 305(b) Report listed dissolved oxygen as one of the causes of impairment on lower Salt Creek. In October 2004, the Illinois Environmental Protection Agency (Illinois EPA) completed a Total Maximum Daily Loads (TMDL) Study for Salt Creek that developed load allocations for BOD5, ammonia nitrogen, and volatile suspended solids (CH2MHill, 2004). This report concluded that a 56 percent reduction in BODE and a 38 percent reduction in ammonia would be necessary to achieve the dissolved oxygen (DO) standards, or if one dam was removed a 34 percent reduction in BOD5 and 38 percent reduction in ammonia would be necessary. There are three dams on Salt Creek identified in the report, the Oak Meadows Golf Course dam, the Old Oak Brook dam, and the Graue Mill Dam located in the Fullersburg Woods Forest Preserve in Oak Brook. These dams are depicted on Figure 1 -1. The impact of these dams on the DO level in 2004 was not well understood. Data on ambient DO levels as well as critical factors such as sediment oxygen demand (SOD), an important factor in DO levels at low flow /warm conditions, were limited. Since the publication of the 2004 TMDL Report, a group of communities, publicly owned treatment works (POTWs), and environmental organizations (the DRSCW) was formed to better understand the causes of degraded water quality and, in particular, to find ways to improve DO levels in Salt Creek. The focus of the DRSCW was to develop a sound database of water quality through monitoring, including the use of continuous DO probes, in conjunction with developing a calibrated water quality (DO) model from which a number of alternatives for enhancing stream D. O. levels could be evaluated. 1.1 Project Goal The goal of this study is to identify the areas along Salt Creek where low DO occurs during the warmer, low flow periods, followed by the development of a calibrated DO model from which a number of alternatives are developed for addressing the low DO areas. These alternatives include the removal or modification of dams and the construction and operation of in- stream aeration projects to achieve the water quality standard for dissolved oxygen. In conjunction with this study, the DRSCW has also collected excellent biological data (fish, benthic, and habitat) which can be used along with the water quality monitoring data to address biological impairment in a holistic manner. This study will identify: 1. Those reaches where the lowest DO levels occur during low flow -warm weather. 2. Identify the primary cause(s) of the low DO based on water quality monitoring, sediment oxygen demand (SOD) measurements, and modeling. 3. Potential dam sites where complete removal, `bridging,' or some other modification would improve minimum DO levels. 4. Potential sites where stream aeration equipment would provide an opportunity to raise minimum DO levels. 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N1�7 CtAA�arrtto�ing.ite„K� ;•` a ",' / ft�►rt d` � �,.. 'Rd • r - s ° ,» ','ka ,�p•�„�° .�. 'iF.'w'v id= %x'�'' .i'.,; -4' x. � ^�� , x. ,�•� "e' 1 -y� \ .� '4A'`i'E, u ti ' . .-,'r" S+ J�'N IQ i.*.�,.:6 l w , lrV',r " a l gair ti ��g li��v+ag��a: . F�a \i\¢ .,« J �Y- f �" "r ,. r, � ''.: `:°. av a o-a t4'i� � .=t ,r:, ` .m; 5 � `" . € `C'� Hr.f,%',, ` �" • i*aa. � ,f. ' c;$: t , }, ,O£'P l ' w£ <0�' w.1, waters hek ur rigs 'r ry„ E .. t• w4� ,0t1:9 2.I, DRSCW 1 -2 - June 2009 DO Improvement Feasibility Study Salt Creek 1.0 Project Background and Goals 5. Permitting authorities, required permits, and regulatory issues 6. Environmental impact on water quality and stream habitat, in addition to secondary impacts and other community issues such as adjacent land use. 7. Financial impacts, including project capital costs (including sediment removal and disposal costs), operation and maintenance needs, and other costs associated with stream improvement projects. 8. Dam owners and nearby landowners affected by stream improvement projects, along with their interest in accommodating such a project, and a description of the impacts of stream improvement projects. 9. Adjacent associated construction needed as part of stream improvement projects (e.g., upstream and downstream stream bank improvements that would be necessary due to altered water levels, adjacent equipment, electrical feed, equipment access for maintenance). 10. Potential sources of funding for projects, including federal, state, local and private entities. 11. Other aspects of stream improvement projects that may impact the feasibility of such a project. 1.2 Water Quality Standards On January 24, 2008, the Illinois Pollution Control Board adopted revised DO water quality standards. These standards are presented in Table 1 -1. Table 1- 1 -11PCB DO Standards �,� ,.- � • _ :_�: ' ^' �- '� � w - • - _ t,� -� �:•Minimum�DO:�: Standard '� ° >rS <'-- ,�;�s�,'•_,:s�. �.�, ��`, es-..` "a��t`. ,'3� p�,��, eye•, �s`� - -� ,? .7�ak..U,S,,�„ .: ,> i; ",� E .. ?` .'t�"` < -4a. •- 4`�dr tr,�t•�r"m"rz' -.�7, _v'' „<�: "Y.x 1Vleasureanent:Iaterval ' y� -.-' °' 't say ' f:.`. -3�s Z.,N.:,_�•a'.._.t4b:`%at'f,<s `.,.,.R.:u� "v. »a5'.',.ett �ul,u �k� .b'.s.:xa.:�i'.::,u7it «::.`.�� •'� '�Y»`v7>''ta� : ..•.pH i i••m: -i �.`. - ",,F °,=b.iy.,3 =,4 -C°'2 �'j �'°' (f` `e;. � e �� -; " ,�•.• March ., 1Jul:` �;,,i,� , k�S: c;;.,v:.. ,'yi,'�,;�'e�° -� b;',.yr• L,,u lam• st'. =`1F Vbi'�4a,+�, �/.^`w'2'S� Mai i4'tiv .' ` �,r +. ♦e bi:..n �.. 9 ji,;i :� -`� f ,C'�!�' ,d{ ,�k gu .. \j+t)`�4.',n. 'u� �`z �.s , ky'rt. `At (•... L� �N 2Jl� b' i - x •- .S'�_ � , u`?C'i . `. „� �•' j�- fv� +�� •` s,',?, „ - '` -. ..�'t �•H e-. a.. �' ..9`,.:r.<;,:k„_. °»..,�,.i.,,;. 'c.:,.��..:�:. -.•, c-'••--, �,•,• „•,T- };�y- ""��- +-- a-'*•,x--s,'m ,- ,•e- ;ree•�."^._ ..�.:.�.. -�.,• e ^" ".,"^•N":'"- =±y;,_'^?;'; -t ;''r�� „--n•. �'r r;;"`�,�r, -, �•r•�,i."i��?rr�aa she:,; ��!'�” y` ;'s'';�s.: .`` •�. 1; r = ,r .��F.� �;?+�: '".�"��+ttN ae,.,.,1� �, �,rh� '�. "' I�e,r•.,� ,k � ";Y,',��'�,' " -' f 4 . , re°` '`rxa'" i• v�,^ :t y eS' ' lri '�v 4' , K ° xrmJ` F•'r`- r >ti+:,4 „{• ;33 time�� ':�s��•j:" �' p 3� "5 'm(��l��:,;�t" ��, _;,; � x� t$ �� ;4� "� ��,��;5 :•,O.�m� //j�� 3,: ky Y�;v`.�, y�. a. ;�'+ fit„' ' t,+• J , �.a a tom' t '' ��; � ' r`,. ,; r5' �•i' • r,. f. "•."l += y,`,�,v �... , q'� _ i Y '-x' ",.Y a CJ, s r4 ,e Y; w�xw:. ~ =•2'a Y't : ��'^`;n' ..` N a rolks :�:�;, �• - t F,is:K fN;'ySK =ss ` :;: =s" •.i o..�... _�:..:4:::;_ 1 Z21, ::.. 5"; Ilk -- r' -.•- -t - -'"-�' c- ,R-��"'} ^^•*,•m- r.rr„•.._ �,5.. - �.�.,a, da�%saveraEe, . _ '. :.4.`0 `".� v r.,. kry t f Y V•,1 _-4' a't'.,��r, x; e.fr �• ,' _q�3, 'y. >9o`o'µ'i �. ,�.. �'� °r3�'tir�u';y�s_v ATV% 'iP. -,�:5 t_`L' =�'s” z;lzsx.ry = P'�} „” "aKi:aF ' - 1; iit° :3�h��e;ay41,•:o;i+,,.'.� =`l'.r '°,�,yrY+'4, �c-- ti:`..,' '�� •F5,_ �:,�.,a .- ...:.a:...�'�`"..r �.a.3�:.�i.. ._- ....h•� -�. C.x.e..F.>S h..w. _..�_.:'.'v, _Y._.�....:..- ;:•3a.%a °,a�.'«: -.k »ii _ .1 G,_.+:. al. �:' r.- :�.,.....:L^.Seu..tn��.e._..., � 4...'.° >'i:,, -: ..i� -- '—� --i '•'�' ' --, -r -S F , ,, �.,,h: c ,.-- 'day :average; �, i w• v. S f5 in A , �;r, • i ?ri .y ?, n ' S',� «< .•v -':�?{ { _ „t 3.,t'9 0 „• 1'� .Y, •.,�;!; °.° f.'..,;y�• l,. `+,�, R „k a. ,n' '"''t :� ao..;.ti. " ".�,'v u. �_,'�,_. 4 n �'k `t'�,a. "xy k' a� ..z.,:'._".'.•' „•��"a1� r.,..: u',�.�- ,.;:..K...t ..ik:°.• x�:�.?.i ....:.3e.3'`o£z�� .._�3...:.i��a..�.� -1 C"W:.�'`L:..•sa,anse_'s�..�_.., -§.fin • c :'_�(��.,R�-- ;ain�ti.,3' "- a.d.G, c_"- --`-`s -.. :,• •F34- .'v'?T"_c leis ;; — IYTMZ. �• z;'r"s'r},rn`S, %w.Y •i'�s,'^'_'G , -- ...•.".� ..p.W,.! C_ ..._ -_ __� .. -sT.;i,9ro'.%" -' 3 "yt�._^,�' °ir -�, -' iT ':1'l. t`.i G -.. ,,. ,o-'7a',. {y� h`Y•�C "„��ti' "}', `�,n .q� � , � i,�1�� 5 16 hrwm�any�`24= hr.,pertod` Minimum DO levels occur in Salt Creek during prolonged hot, dry periods. As the water temperature rises, the daily minimum DO values become lower. From a practical perspective, any solution must address prolonged hot, dry periods that can occur in June and July. Based on in- stream monitoring, the minimum DO standard of 5.0 mg/L will be more difficult to achieve than the 6.0 mg/L weekly mean, as photosynthesis will increase DO levels during the daylight hours well above 6.0 mg/L. Therefore, for the purposes of this report, achieving the minimum DO standard of 5.0 mg/L in June and July will be the basis for evaluating alternative approaches of dissolved oxygen improvements in Salt Creek. DRSCW 1 -3 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions 2 EXISTING CONDITIONS Before evaluating alternatives for improving the DO in Salt Creek, it is important to understand the existing stream characteristics. Factors such as stream depth, canopy cover, sediment accumulation, stream bank erosion, riparian zone composition, wetlands, stream slope, and bank heights are all important during the alternative development and evaluation process. In addition, SOD measurements have been completed and continuous DO probes have been installed at strategic locations along Salt Creek to better understand the DO profile under low flow -warm conditions. 2.1 Geomorphic Assessments Natural streams are in constant dynamic equilibrium. Although imperceptible over years or decades, a stream in equilibrium moves within its floodplain both laterally and vertically over long time periods. A channel can be in balance with the hydrologic and sediment influences or can be in rapid transition as a result of changes in the watershed or within the stream corridor. Urban river systems are often in various states of disequilibrium. The development of Chicago area watersheds has significantly increased the intensity of land use. The impact of urbanization on stream systems is well documented and includes changes in the hydrology, water quality, sediment supply, and ecology. Other impacts include isolation from and reduction of available floodplain capacity and installation of road crossings and other lateral and vertical controls. Hence, urbanization can significantly increase stream instability, as shown in Table 2 -1. Table 2 -I - Impacts of Urbanization on Channel Stability r y -- �„ �?r :'�csa; F Vii'` -=rx`" .*a• - f.a ,. «' >*' .�<aF: „• .� i�- r,.�.'v i; ^,° ` ".s';R _ `-�€�,'r 11 z. �, .I+• �;,`ya• �.��TM;a� r �`r �kProbable�!Cause� � � prµ �. �..i.x��,L��.F' � '1`W..ms�.w„ea,�: ita.:_.>....�s. -. v.>�.wr.v�.�:4e.- ,...__,__�_. _ �.; .,...... •-.... -...,� ��..._? ..m.. adsea, rat •s�,��r.Y;.� �;;r �"- �'y'�` '�` �� `;�.s �.�; `fiw rst� ;�; t°a'�`��°c 'ice _^,• :�i'c�n. �;` �i�.?�... �%= Rernovaljofriparran egetation 'and£; >instream 'X,'j•+'t x za,* Yw..,q ^,�.a4. ��'y.' >f` debri n` L M. woody t=om'. � � Change iri. " eotechnical- aloadin . ; a bAlteration of baseflow; s �vel ; q(� ` {t �:��, 1' ,fi.7�p^ ��, ,' a�,i9.' ��a. ,.m`� yvi �<., " t. - ra+'`t; z::� ., •.e,x' 4. ;v,Y,t.«"- -�, R =2a 'Y., z. l+d:s"ra; t r ^x' .N.;R..a ac...., characteristicsof tth`ebanksa _aa,leVelsandtuntn ; ofsaturation' r= .,�na.:,., _. Aa=. ,�gltaa_. r� ,. �� :. "'s- '* >e..s.r� v �' � I -.. �x.= 4:` s'.'',` z±',''• iti^'@` Foe�L_ w'§a�;x��n "'c`m`,,,s`.-''''t�,s av �1',t> #`v a Y',�`+ -' �• = ?Z.�''';'�'^`' � :t, . orestat� g 5 �.. •f�Change��m�npanan�mana ement��:4- �� •3�`�� Def � on�and��turf ass.�chan es. 'ffi�i&Kvxitig„3.z�•_a..•k"�: � '�'.w'�kw ��:a taw+ x. ?r1�: 93:. v:; da. o-t* J: r54TZ�ro➢'v« a�. a.. a.. a1E2Y�. aR?'$ tvxac�: Lnra. �+ �Yx .•.]*.sek,4,.asi.aRits.'xs.. ��-uk iX.'• c�.�''�a '2-S^ y, - �`f'�Yit' �3t�� r. �Increasein4streamtem eratures� °� . r w a• ��t_n__�.z. p x a ".Loss} of'canopy cover F '� DRSCW 2 -1 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions From a geomorphic perspective, Salt Creek is a disturbed system, with channel features typical of those found in large, fully built -out metropolitan areas. When the area was developed, small tributary streams were either put into pipes and buried or were confined to narrow, straightened ditches. Floodplains for these headwater channels, as well as the main channel, have been filled in or separated from waterways by large berms that concentrate flood flows into deeper narrower channels. Floodplain and drainage surfaces have been covered by pavement and storm water is now directed into storm sewers that discharge directly into creeks. Where rainfall once seeped into soils and traveled as groundwater into channels, storm water is now diverted into artificial waterways and enters the stream as runoff at a higher rate of flow. These processes lower base flows and increase flood flows, making Salt Creek a "flashy" stream, particularly in its upper reaches. 2.1.1 Channel Evolution Schumm (1984) describes the evolution of stream channels (Figure 2 -1) that adjust geometry in response to changes in the watershed. In essence, if a channel needs to adjust its cross sectional area, it must move through the evolution stages described below until it reaches a new, stable geometry. The Schumm system classifies streams by their place along a continuum of channel changes toward the more stable geometry. This process is common in urban systems where channels are continually adjusting in response to increasing water input, decreasing sediment load, and often significant physical alteration (channel straightening, floodplain width reduction, etc.). It is useful to describe the stages in Figure 2 -1 to understand the process. Stage I represents a stable channel configuration. As sediment load decreases and flood magnitude increase, the channel begins to erode (incise) into its bed (Stage II). The incision process is followed by lateral bank erosion as the bank heights (h) exceed a critical height (hc) and collapse into the channel. Stage IV occurs when the bed begins to aggrade (deposit) and the channel banks are approximately equal to the critical stable height. The bank height will continue to decrease until a bankfull condition is achieved that is consistent with the new bankfull discharge. A new incipient floodplain will develop and vegetate as part of the final (larger) stable geometry (Stage V). DRSCW 2 -2 June 2009 DO Improvement Feasibility Study Salt Creek I h < hr D h>h, ID h>h, 2.0 Existing Conditions 17 h -%a h, f• h MUD SAND AI._ DRAPES COUPLETS V h < h, NOTE:he- cr tcal bank hoight PRIMARY 1 NICKPOINT V TOP BANK PLUNGE POOL DIRECTION OF FLOW SECONDARY AGGRAOATIONAL ZONE NICKPOINTS BED PRECURSOR NICKPOINT OVERSTEEPENED ZONE Figure 2 -1- Channel Evolution Model 2.1.2 Bank Erosion Bank erosion is part of the natural processes within a stable stream and is balanced by deposition of sediment on floodplains and bars. Erosion provides the needed bed material, allows recruitment of large woody debris, and encourages channel variability. However, `excess' bank failure associated with unstable riverine systems and massive failures that threaten existing infrastructure can cause unacceptable environmental impacts and consequences to private and public resources. Bank failure can generally be attributed to 3 basic processes (Thorne et al., 1997): subarial wasting, hydraulic scour, and mass failure. Subarial wasting is not considered to be the major driving force for Midwestern urban streambank instability and is not discussed further here. DRSCW 2 -3 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions The common result of urbanization is a significant increase in bank erosion due to hydraulic scour of the channel bed and toe of the bank. When changes in land use result in increased water velocity, streams begin to erode their bed and banks beyond the point of equilibrium. Excess hydraulic scour generally can be addressed in two ways, either by reducing channel velocity and thereby reducing erosive force, or by armoring the channel to resist the erosive force. Reduction of channel velocity can be accomplished either by increasing the area of the channel, increasing the capacity of the channel and/or floodplain, decreasing flow rates, or modifying slope through the use of grade controls. Following incision, as noted in the Schumm model above, hydraulic scour combined with mass failure can lead to extreme bank erosion. Mass failure of the streambank is often the result of increased hydraulic scour, and/or change in riparian vegetation management associated with urbanization. There are numerous bank failure mechanisms due to various loading and resistant conditions, including differences in soil characteristics and vegetative reinforcement. Streambank soils can vary both vertically and horizontally, and can generally be classified as cohesive, non - cohesive, and composite (banks with layers of soil that have significantly different characteristics). Each of these types of streambanks presents different engineering challenges and different solutions. The equilibrium processes of scouring and deposition of soil layers within an alluvial valley can provide significant variability in the soil conditions within the valley. Hence, the type of bank material can change significantly along a stream length as the stream passes through different depositional eras. The ditching, dredging and straightening of channels is termed channelization. The result of these hydrologic changes in Salt Creek has resulted in dramatic geomorphic changes. Channelization is perhaps the most common form of channel disturbance throughout Salt Creek, and its effects vary. Where wide ditches have been excavated, shear stress on the banks is relatively' low, and banks are stable. Because these reaches lack sufficient energy to transport sediment through the reach, many of these over - widened stretches have aggradation problems, whereby fines such as silt and sand are deposited. Just above Butterfield Road is an extreme example of this over - widening. Channelization increases the effective slope of a stream by allowing water to travel a shorter distance, increasing velocities resulting in incision. The newly created steeper slope is unstable given the hydraulic conditions, and begins to headcut upstream until a lower slope is achieved. This often results in deep incision upstream and aggradation downstream. Common measures to address mass failure of streambanks include decreasing the load by reducing bank height, reducing bank slope, improving drainage or planting stabilizing vegetation (to reduce pore pressure), and/or increasing the resistance to failure by geosynthetic reinforcement or revegetation. 2.1.3 Sediment Transport Understanding sediment transport characteristics of a stream is very important in understanding the stream stability and characteristics. Alluvial _streams within urbanizing watersheds frequently experience rapid channel enlargement. Channel response to urbanization has been described by Leopold, et al (1964), Hammer (1972), and numerous others. During the initial wave of construction, sediment loads reaching the stream from the watershed may be elevated 10 to 100 times compared to pre - construction loads, with the attendant destabilization and sometimes DRSCW 2 -4 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Fxisting Conditions flooding damages. Typically, high sediment yields during the construction phase are followed by reduced yields once infrastructure and storm sewer systems are fully built (Kondolf and Keller, 1991). However, as the fraction of the watershed covered by impervious materials increases, watershed hydrology shifts dramatically. Flow peaks become sharper, higher, and more frequent, while the sediment loads reaching the channel changes. In the absence of bed control (e.g. bedrock outcrops in natural channels or hardened stream crossings in urbanized areas), channels typically respond by incising. When bank heights exceed a critical threshold for geotechnical stability, mass failure ensues and explosive channel widening occurs. Sediment supply changes such as local and upstream bank failure, upstream modifications etc., and transport capacity changes (channel widening, meander cutoffs, construction of additional crossings, etc.) can make a reach aggrading, in equilibrium, and degrading over time. Sediment transport continuity describes the ability of a stream reach to transport the sediment that it receives from upstream sources. A stream reach is considered to be in equilibrium if it can transport the sediment it receives within the reach and from upstream sources to downstream reaches. A reach is considered to be degrading if its transport capacity exceeds the sediment supply (and hence the river will erode its bank and bed) and aggrading if the supply exceeds the transport capacity (leading to deposition). 2.2 Stream Characterization In general, Salt Creek can be characterized as an urban stream with low gradients and extensive channelization. Canopy cover in the assessed stretches is variable due to development, channelization activities, and widening of the stream bed. The loss of canopy cover results in higher summer stream temperatures and in some areas of Salt Creek, the establishment of excessive rooted vegetation. Flow during low flow periods is dominated by effluent from the wastewater treatment plants along Salt Creek. The slope of Salt Creek in the critical stretches is relatively flat, with many reaches having a drop of less than 1 foot per 1,000 feet. The steepest drop occurs between River kilometer 28 and 26.9 (below Route 83 and above the over - widened section at Butterfield Road), where a drop of 1.2 m occurs over a 3,000 -foot reach. Slope is critical as the stream velocity is influenced by the slope, and stream re- aeration is influenced by the velocity. In stretches where re- aeration is low (due to flat terrain), maintaining minimum dissolved oxygen levels becomes more difficult. The headwaters of Salt Creek have incised in steps, with road crossings sometimes serving as grade controls, preventing further incision. Road crossings, whether bridges or culverts, can often be the cause of incision. In some cases, however, rock is placed under bridges to prevent scour of bridge pilings or abutments, and these rock riffles often act as grade control, preventing downstream headcuts from migrating further upstream. Salt Creek from Algonquin Road upstream shows a stepped incision pattern, with the deepest incision being found upstream of Plum Grove Road. In some areas, the channel has incised more than 1 m, and subsequent widening has created extremely large channel cross - sections. Landowners have experimented with various bank stabilization treatments including timber cribs, rock riprap, concrete rubble, and sheet piling. All of these methods are hard engineering and prevent the channel from DRSCW 2 -5 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions assuming a stable cross - section. Thus the erosional energy of the stream is translated downstream to other properties. The many road crossings and dams on Salt Creek act to impound both low flow and high flows, potentially increasing flooding. The dam at river mile (RM) 29.5 (river kilometer 47.5) floods over 2.5 miles of channel (4.0 km) of channel, drowns the floodplain and backs water upstream for 3.5 miles (5.6 km), virtually eliminating any lotic habitat that may have existed. The dams on Salt Creek have also reduced the rivers sediment transport ability by capturing sediment behind the dams. This creates a secondary situation downstream, whereby sediment - starved water erodes bed and banks and streams become armored, over - widened, and incised. F000dplain encroachment and development is a major impact to Salt Creek, especially upstream of RM 10.7 (river kilometer 17.1). This is typical of most urban streams, where parkland and natural openspace is preserved in the downstream reaches and the headwaters are fully developed. This is the reverse of what is required for streams to function geomorphically and ecologically. Because the headwaters are where hydrology and sediment transport originate, development of these areas degrades the stream in its headwaters. Residential development has the biggest impact on Salt Creek's headwaters and continues to confine the channel down to RM 22.0(river kilometer 35.2). Downstream of Interstate Highway 290 (RM 22.9 km 36.6), the floodplain is occupied by numerous detention basins. Between RM 20 and 30 (kilometer 32 and 48), there are 11 such large detention ponds adjacent to the stream channel. All of these encroachments limit the ability of the stream to meander. If a restored stream is to be allowed to function geomorphically, it must be allowed to meander across its floodplain. This requires space, and the limits of meandering must be established. In most cases, however, the stream is bordered by infrastructure and is then hard armored to prevent meandering. The riparian area of Salt Creek is largely wooded, but varies in width from 0 feet to 1,000 feet. As with most urban rivers, stream banks and riparian areas in residential or light industrial neighborhoods are often armored and most trees are removed. The Forest Preserve system has retained the floodplain forest community in many reaches. Eight major parks and golf courses along Salt Creek represent a significant impact to the riparian corridor, as they have removed most if not all of the riparian trees from the stream banks. Often these reaches are accompanied by hard armoring, either by A jacks or riprap. Hard armoring of stream banks is prevalent along Salt Creek and presents a major impact to the aquatic ecology and geomorphology of the stream. Hard armoring is sometimes required to protect infrastructure such as roads and buildings from eminent risk of failure due to eroding banks. However, much of the hard armoring encountered was in the form of riprap or A jacks. A jacks can also prevent the movement of amphibians and other aquatic species. Animals, such as turtles and frogs, depend on banks for upland access, reproduction, and breeding. A jacks prevent any such use of banks. Installation of these practices was observed upstream of constricting road crossings and dams, on the inside of meander bands, and along banks that were not eroding, in some cases with a bank full height of less than 3 ft (1 m). A jacks have also been installed in long reaches of forest preserve land where no infrastructure is present. Observation of stable reaches throughout Salt Creek point to the importance of woody vegetation for stability and both artificially and naturally stable reaches repeatedly show that small diameter material such as cobble and gravel are often adequate to provide toe stability. DRSCW 2-6 June 2009 DO Improvement Feasibility Study Salt Creek 2. D Existing Conditions Invasive species such as buckthorn and garlic mustard have taken over many sections of floodplain forest and can influence the geomorphology of the system by increasing floodplain roughness. Normally, floodplain forests have little understory vegetation and flood flows can pass freely between large trees. Buckthorn and garlic mustard add significantly to floodplain roughness, basically filling in the spaces between trees. Eventually, this increased growth may force more water down the narrow channel width. The lower reaches of Salt Creek, below the Graue Mill Dam where the stream is allowed to meander slightly, resemble more natural stream channels with regular riffle -pool sequences, large woody debris inputs, depositional bars and scour at meander bends. 2.3 Flow Data The total drainage area in the Salt Creek Basin is approximately 147 square miles (380 km2), extending through Cook and DuPage Counties. The creek originates in northern Cook County as the outlet for Busse Lake within the Village of Inverness, flows south into DuPage County through Oak Brook, and turns east and flows into Cook County, discharging into the Des Plaines River in Lyons, IL. The total stream length is approximately 45 miles (72 km). There are two main tributaries on the lower portion of Salt Creek', Spring Brook and Addison Creeks. In the segment from Spring Brook Creek to the rivers mouth, there are seven sewage treatment plants, and the MWRDGC John Egan Water Reclamation Plant is located upstream. From a DO perspective, the industrial dischargers were not deemed to be contributing deoxygenating waste to Salt Creek. These point source discharges are presented in Table 2 -2, and the locations were included in Figure 1 -1. Table 2 -2 — Municipal Wastewater Treatment Plant Discharges >iw" °,t�a'f� }'Y'f' "� �y .�i. F �M11 �.t �`F-c $�.I'�t �'f. `u` {F.t`, x ?,�+�'�'x'4�'FAa {A`i��■� /'i� M�� :.�,�� `� 40�'' i. .c, .l t" -`d^, ryc fF`x ,.W ze` r�Yr3' `F ? '' �', •'- {,r, x"i�, `^�.1%'�4�'' ".ibc S 1 nv't ver` , civy�r�''`k,,,;v, „.m`'�'�%' -' from moutli. . • s � .r..,.._: ;4s`: < —�,', anmw "- �c- :�'"`Tre'« a; °� >-. s,"_ 5 a; "csa 5 uc,�K, s ", ' "T El'inhursta Wa'stevvater,.A; t. < r. x _ 8:1 Treatment -Plant' {`` �[ "'""",r ^��,^'.,;.'T:.; " "�t�'�,- rg- ,�- ,n� -y..`^ _' •� ^^n';f�� 5}, <x"'�n ,^,F�.A��;�t�'.r�'�$'s,�,z `x- .��w,��,r� } �� ` >� �� , - � Treatment ;Pl'ant v � ..�, � ,�, � � ��, . ��.. , ..� r,; ;.�•,: 3P4`` 1V at er--,•,,"',.�„`��;:x'*•r. .- '��Vi�11aPark "Wet �Weh-�� •�:, � : F., :��.1'� y g�,�_ , ; ,_� �3� dy, Treatment ,r�; -r , r,"'a cr�•ng-i ? '?' i:.`Li �`� nn `i f c;74.. ;f' ' ^-` wr. nk o S.outh� AJAdd �.k.`.<, , aSt?:._` S. aar... '...,.��::;.�{i,:i.�'1#ai.,::l� r�.`1..�... ..�-tik ._..�.?:�';. ...:.%z�'�, i� .ti ,. :.Y.�.:._ ,<�F :.•^ :v'�ti�ex�.: `��iC`.z'� �.... -.,., f z,.•., a-�.s..._.•y.w..v.._,.,..- - ,.., --.. �..r� �._ .,....,-- -�-.,- a- �...* -r 4--� '.`4e `„,�4 3 �•� s` �� ..� --_ � _ ,� :` .��s ,�AddiscinxNcirth -:'STP �W'� ^ <,.v, WoodDaleSouth: =STP:�:`:<<'x:, �40:5�=.y'- :`'x'..�, a<'t1e xa�"..'. �Y., �� ".a8= ,"��.`�,S�;w`�.:.�:.� {�'� .:.'�;a v.'%k..�;::.. :,..:aa.- :.- a".��`:4, i�- ..'s.rC. eS"..:_.a...<i��as..��c''n ati �.ti:�.s�.i�Y,i:. .;. �� `�.,6"�+.� ^wxF3`:...;.?.�.ro•�r. hx .x. .a.A`7�'r'"' a"Y *:'':r.•rrty zl � "r _Itasca, STP, k I�TVRDGC: _ — Via* . . r "F, w.. *,',-� YJohieEgan [x�}{ r >. :'`cti;:�:�ri rf'; ',.':.�� ,C .{ ^k�_,�. .... .-. .Y r,'�-- F' -a��1 ::.F %y5`�.r �1'tx�♦ ,��`��ev �4�T.. /�. 4�'�'; �r� M; b�Y{ ;Water`Reclamati,on_.Plant 1 Lower portion here is understood as the portion south of the Busse Woods Dam in Schaumburg DRSCW 2 -7 June 2009 DO Improvement'Feasibility Study Salt Creek 2.0 Existing Conditions Selected published flows for Salt Creek are listed in Table 2 -3. Table 2 -3 - Published River Flows - �- �-ir;-n�-- ^-:.-r'+^=1� -�t4� X_. �:__'"_' �`_•'-...- �------ _`._..._._K_._- ,«..r,_ -�-. -: -`-s. -fib; �.�{ qua-_ S'�r'= ^ry,?�b��,3o�r:'wti: _ -i. k 7 =Da 1.0 ='Year 00"', ,. .a -u' r'7 5 g� -,lL ` •5 s" b• a r. ;,, C` �'��.`�� 1" ` :tow'Flow; °cfs : Q °e" Flow,,'cfs �i' - -- ��:. ^` - ,� ��. ::..: _.�- _- _= �_._�F I : i, -�_�,3 � a � ` � •'t' ,: b, }�-.'.�� __ -< -s : taw - - _ -- �= Above Elmh urst� J �.:... i`..= .�-i.. - �F �� Below°Elmhurst .;a��,t �t:. °,� ;,r«, '�45sa�.�:��;� �,.u= A;��f � ti Q 4 • 'k "74 , =s'' 15�,. 1 i�'T�'^ �5" � . •Tt.. ..` �'.. .S4' \, i }�ux".�� ~ �• ki +m ,�`i .�:s�.�! � S ' y F n .••,. ` {� ( "'•o U''J FK�d`3: `'� "'tt'�C'? � q. i �n „M,'' ='_$i �,; ;s•:, "'_--_- -�"° i` _„ ,i.-� g-s " --"*-' �-- r,'-- ^-- .�—.^---- r- ';,..- -�..�, r� t t . "s�.-: _ {" `--- tiY.,- i-,�:Y �;' 4F'Se Western,S riri, D. ,tl 1�0 ,' '3a` 1 '`V ca't• " `�t Ate<• � i' s x�,`'. �* �S: ^9. -:e'' F n, ^air ��r. `y�`axla� "7.. C.F�'us aw`a`<'s� ' �.�.`'..`.. ,i fi`.� - �. .i..`�.cs' 'F' x*' �,s:P..:' b.tge - n- .';.- r-,_•__..,- --raa�-*c-- +'^r.�. . `�b� '' y' ia4'rz.t �ti-e-.•'s- -rX. i. 'T: , 11. fi r t :'"• `r'; j "�. .rAbove`'AddisontCreek�r' ,., .a" t, ;� �; �� ":� � ; 3.6.5 �, � �� ,�.84��,,z :. ;r,,:..tt ., �'4`• F ` �. �, ay 1 �.� .r,.,l � M�a; "� 1 ^ \sit x -q; Y�; :t.J�`_'�'�' `�• i�: ui ,� y.�., ��..,' • r"' -' :S+ ti �.ak� ^�'. �, c�r` ,d � � `'a A� '^ 3 � �"�s h.;.`3.1n! `w.Si_w4 , >�� :1�� •� �� Via," _...�g:..y,':''..� .tea,. ...:�.•�. •- :.'�':�- °'��i�. 1��.�.%,,..: - :..c.:...t._».u�..w�.��..: ;��:.a.tr.l �,:u�`�'bn_......'.`�`F :s�:�,,....3,:°,'S k-G��a � s,--••' 3"•--••--,... r +;- :-r- ��^..•_- r,..- x"'- ro'� - -; 1 i °--•,. _ - n --. ^-n tones- "'[-�''°' �. ;Entenn Des tPlaines , { ;; X37 , :N,;,, , ,,�. s.' �/� _kl l_:....,`.,. ^ � c,-- ...«.. �. _. _...�. _. � ,..�,n.....,.._.�I"i_<i;� --_.xa :s�._. S '� � L....,:a..�,...� ,�...... _..-� ... _..... �' ,._m.z. i�a:�i�r�.�� =.�:,. .. _i'�1 '. � ?a _ _ • f T� ' Combined Sewer Overflows (CSOs) and Sanitary Sewer Overflows (SSOs) contribute to lower DO levels at low flow conditions through historic deposition, which was measured as part of the 2006 and 2007 SOD studies (HDR, 2006 and HDR, 20070. The wet weather DO impacts of these utilities are not included as part of this study. Reach Descriptions In the 2006 303(d) List, two segments of Salt Creek were listed as DO impaired, Segment GL -03 and GL -19. Segment GL -03 starts where Spring Brook Creek enters at RM 28.3 (River km 45.3), just north of Irving Park Road, and Segment GL -19 is the final 3.1 miles (5.0 kilometers) of Salt Creek from the junction with Addison Creek to the Des Plaines River. The final stretch of Salt Creek has low DO levels attributed to the poor water quality from Addison Creek. The Illinois EPA Qualitative Stream Habitat Assessment Procedure (SHAD) was utilized to describe each stream segment based on the observations collected during the reconnaissance. The SHAP index includes factors for bottom substrate, deposition, substrate stability, canopy cover, pool substrate characterization, pool quality, pool variability, canopy cover, bank vegetation, top of bank land use, flow- related refugia, channel alteration, channel sinuosity, width/depth ratio, and hydrologic diversity. Based on the subjective evaluation for the aforementioned factors, a SNAP score is determined. These values correspond to the ratings shown in Table 2 -4. DRSCW 2 -8 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Table 2 -4 - SHAP Ratings .ns w Rating;ti:yts;SHAP,,Score b =, Excell'ei7t° " k• �� ` • >; ' ' : T' F "�. �w.ii��.�i;l ?..i_i �'��`.t w• "vi "R�''�..,'YSr ... ��...:....��.�.. ��t 4;5,x, �� H-�;�• 141 "v�� 1.00•,��r�s.�t c...,� e.:.."_:k ;._c:,�d.�a:,t.:h. :;,', s`�'.3,= _9...iras__�.�. L�`"�q.�.t...•o:.`... ..�i. y:i �.- ��..�•;...,n; ."^ _iP`�.""i' �^iv-- ;^= �'�".i .'i'7..mcTM e ?irz` �•,, sa;} �: ;+ � a "•, "' ,.l}, a, :,.�'� `iii• "I �Poor�u�_ - -,$ Channelization, lack of canopy cover, effluent dominated low -flows, and other factors all contribute to the vegetative growth and subsequent lower early morning DO levels. A reconnaissance of Salt Creek was completed on October 13, 2005, during a period of low -flow conditions, from the Addison North Wastewater Treatment Plant (RM 22.6, River km 36.2) to Graue Mill (RM 17. 1, River km 27.4). Figures 2.1 to 2.8 in Appendix A present a description of the findings. A description of each segment is provided below: Addison N WWTP (RM 22 6, River km 36.2-) to Addison S WWTP (RM 20.9, River km 33.4) This 1.7 mile (2.7 km) stretch has a SHAP score of 60, or fair aquatic habitat. Water depth ranged from 0.6 to 2 ft (0.2 m to 0.6 m), with predominantly a silty -sand substrate until below Lake Street (RM 21.7, River km 34.7) where the depth increased to 3.0 to 3.3 ft (1.0 to 1.1 m). The substrate in this pool area is predominantly silt. A concrete "curb" dam is present at RM 22.1 (River km 3 5.4), just upstream of Lake Street, and log jams are backing up flow at Lake Street. Wildlife observed in this stretch included great blue heron, mallards, king fisher, and beaver. Good floodplain habitat existed through much of the reach with shallow bank heights and moderate stream bank erosion. The creek has some meanders in this stretch. North of Lake Street, the riparian zones were wooded with fair to good canopy cover. Addison South WWTP (RM 20 .9, River km 33.4) to North Avenue 19.5, River km 31.2) This 1.4 mile (2.2 km) stretch has water depths ranging from 0.3 ft (0.1 m) where stream bottoms vary from firm clay to silty sand, to pools up to 4.9 ft (1.5 m) deep with firm clay bottoms. Immediately below the Addison South WWTP the water depth was 1 ft (0.3 m), with a gravel bottom. A log jam in this location had an accumulation of floating duckweed. Stream banks were approximately 4.9ft (1.5 m) high with virtually no adjoining wetland areas. Just above North Avenue, soft sediment, 6 inches in depth (15 cm) was present on the inside of the bend, decreasing to 2 inches (5 cm) of soft sediment in the center. Canopy cover in this stretch was relatively good. The SHAP score improved in this stretch to 96; however, still in the "fair" habitat range. This stretch had fair canopy cover, several riffle run complexes and undeveloped riparian zones. This DRSCW _ 2 -9 June 2009 DD Improvement Feasibility Study Salt Creek 2.0 Existing Conditions stretch was relatively unchannelized and had good stream sinuosity and habitat diversity. Salt Creek passes through the Cricket Creek Forest Preserve north of North Avenue. North Avenue (RM 19 .5, River km 31.2) to Route 83 (RM 182 1 River km 29.0) This 1.4 mile (2.2 km) reach includes some long channelized segments and passes between a former active quarry currently used by DuPage County for flood control and an asphalt plant. A turbid discharge was present adjacent to the asphalt plant. Below the railroad bridge (RM 18.9, River km 30.2) to Illinois Route 83 there is a good series riffles and the drop in elevation is more pronounced than the remainder of the creek. There is an oxbow cutoff just above St. Charles Road (RM 18.3, River km 29.3). South of North Avenue the water depth starts out between 2 and 2.9 ft (0.6 and 0.9 m), with up to 3.9 inches (10 cm) of soft sediment, diminishing to 1 inch (2.5 cm) of soft sediment in the channelized section without canopy adjacent to the quarry. The SHAD score in this reach declined to 91, still in the "fair" habitat range. Wildlife observed included great blue heron, king fisher, mallards, and beaver. Instream habitat was fair north and south of the gravel operation. Although the stream was more channelized than the previous stretch, habitat diversity and canopy cover were good, outside of the stretch adjacent to the quarry. Illinois Route 83 (RM 18 1, River km 29.0-) to Illinois Route 56 (RM 16, 1, River km 25.9) The riffles continue below Illinois Route 83 in 1ft to 2 ft (0.3 to 0.6 m) of water over a gravel substrate. A large storm water outfall is present at RM 17.9 (River km 28.6) and two WWTP outfalls (Salt Creek and Elmhurst) are present at RM 17.8 and 17.9 (River km 28.5 and 28.6), respectively. Water depth generally continues between 1 ft to 2 ft (0.3 and 0.6 m) with a firm bottom. An additional riffle exists at approximately River km 27.5 and a double sheet pile dam exists at RM 16.9 (River km 27.0) by Jackson Street. Salt Creek narrows above this dam. Below the dam, water depth increases to an average 2.9 ft (0.9 m) with 1 inch (2.5 cm) of sandy silt sediment over stiff' clay. Evidence of beaver and muskrat activity is present below this dam for the next 0.5 miles (0.8 km). Salt Creek above Illinois Route 56 (Butterfield Road) opens into a long, wide area, 0.9 to 2 ft (0.3 to 0.6 m) in depth with virtually no canopy cover. The stream velocity is negligible and rooted vegetation has taken hold in the bottom. High levels of aquatic vegetation are generally considered detrimental to overall DO level, as respiration at night depletes the DO. Sediment depths are 2.9 to 3.9 inches (7.5 to 10 cm) along both shorelines. Closer toward Illinois Route 567 the vegetation in the stream begins to subside and stream bank heights increase to 10.2 to 15.1 ft (3.1 m on the west bank and 4.6 m) on the east bank. The SHAP score for this stretch, 78, remains in the "fair" range for habitat. The habitat diversity (riffle /run/pool), canopy cover and instream habitat are good in the northern half of this stretch. The southern portion is more channelized with poor canopy cover and poorly vegetated riparian zones. DRSCW 2 -10 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Illinois Route 56 RM 16.1 River km 25.9). to Interstate Route 88 RM 143 (River km 23.0) This 1.8 mile (2.9 km) stretch is through developed property in Oak Brook. Below Illinois Route 56, the wide stream run continues, ranging in depth from 0.9 to 2 ft (0.3 to 0.6 m) with a silty gravel substrate. The canopy improves below Illinois Route 38 (RM 15.7 miles (River km 25.3), and the creek narrows, and deepens to 2.6 to 3.3 ft (0.8 to 1.0 m). Velocities noticeably increase and the substrate changes to cobbles and sand. Stream bank stabilization has been installed below Illinois Route 38 but further downstream serious bank erosion exists. Salt Creek turns east at RM 15(River km 24.2), and the water depth deepens to 6 to 7.3 ft (1.8 to 2.2 m). This pool is heavily channelized and has a sand and gravel substrate. As Salt Creek approaches Interstate Route 88 it becomes shallower (1.2 m). The SHAP for this segment declines to 69, still in the "fair" habitat range. Similar to the last stretch, stream habitat quality is greater on the north end. Below Illinois Route 38, the stream has fair canopy cover and wooded riparian zones providing filtration. Near Interstate Route 88, the instream habitat decreases as Salt Creek becomes a large pool with little habitat diversity. Interstate Route 88 (RM 14.3 River, km 22.9) to Graue Mill Dam (RM 10.7 River, km 17.1) This 3.6 mile (5.8 km) stretch has water depth varying from 1.0 to 5.9 ft (0.3 to 1.8 m). The northern part of this section flows through two golf courses. Between Interstate Route 88 and Cermak Road, Salt Creek is 2.6 ft (0.8 m) deep with a mud bottom 2 to 5.9 ft (0.6 to 1.8 m) deep with gravel substrates. As Salt Creek enters the golf course, it deepens from 2.9 to 5.9 ft (0.9 to 1.8 m) in depth and the banks are lined with caged rocks. The bottom is generally firm. The stream then enters the Fullersburg Woods Forest Preserve south of 31st Street. The Old Oak Brook Dam is located below 31st Street at RM 12.5 (River km 20.0). This section has soft sediment to the north and hard clay to the east/south. Serious bank erosion was noted south of 31 st Street RM 12.3 (River km 19.7). The last 1.6 miles (2.4 km) of this portion of Salt Creek is a long pool with clay bottoms upstream transitioning to softer sediments downstream near the Graue Mill Dam (RM 107, or 17.1 km). The last 330 ft (100 m) of this segment had 1 ft (0.3 m) of sediment under 4.9 ft (1.5 m) of water. The SHAD for this segment was 55, indicating poor habitat quality. The section had poor habitat diversity, scattered canopy and was mostly deep pools. However, areas with good riparian zones were present south of Butler National Golf Course and within the forest preserves. It should be noted that the only instream wetlands were noted at the south end of this section. Below the Graue Mill Dam, a DO impairment has not been identified until the final 3.1 miles (5 km), where Addison Creek joins Salt Creek. 2.4 Habitat Summary The SHAP scores and the habitat conditions for each segment are summarized in Table 2 -5. DRSCW - 2 -11 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Table 2 -5 - SHAP Scores �'`'''�•zy?T,".�'a'r'; ",•„%A"- ^ "°- r.�- r ^-r•^; -^�.z s { " ice; .. a °., �`:F_ w = V , " s' u '� : clyi x. ^ 5• , < � i a c_£ ` ; : '¢°'�t M*= �'3,�`FT'Sx ". a,- �- +Tr't 'w,. - ._.y....- r- •�y,�s � -- �:- '„".,� ,rtc","".r. S =. ' v. - .+, -' e+,'' ,V ; ra cy A)s� t Yw vE " s :"` fl . " :, + s J " 4`•��.: }. '.!k. ' FY ., • "`e3s::`L .i t. •�` F„ , .sr `'.:i5',E:..}+.s- . a L <°� F.,fin t •.L: ,,'M ?0 m i� , .m H;4 }i� ' ts^v.i,'e: n � ;: * ,.�. d, ', r i ` H ^'`a- b` o. iA 'ta<t.ig�Wn,� YF ••fir"5�,t7y'd^h4Y „. F$, _ C ' -7,r F, �Asess nfi _ ' : s rY`y,Y F�,7d J x t y x ,'¢•., - ,,, jai Wo `” x3. ,; , <4T, Q ,,,�, .,t 1, . c: ?r's �" ,'.T�,p �:�_ 'na k' '' !•� nxi ro ' °Fl,.ry,aP L "F' �y,�� •4._ � ~" ^ "R ,g:"' : , x °s� '=r .t =, T. �'"x^ ,, , tin,; Sal a 7��e_S•;. 1 wi � -_ S'� -�''� 7 �;�' ,p�. � �:7�:: ..�'.- :,�:..Streaan Reach, .� � .�,��., >r ,�•,, ,�� , ,� .�'r co 'w °re�,�� ^,' ," �,. :�., _.E .,� �.� _•:,. "� .�,. -„ .� ��SHA'Pa:�r "S'r ;n,hr`�. t', ,r g^, Q'a.•.. ;�, �. �'d T�.r.uti$..; '•'P� e,,i� };M' , {: �z,o `i �'"x ��'y,.Y` =iF' �\'�'i+```�,,. _ J• c,r,�3`,yK^sr< 4.xF-;5�,^ y$r,s. .,p 4.o,x "•o4C5 �`.a��_sc .. �;rd�, - •- •-- =. -_„rr - '-ate -- :.1 _ Addisb= ;�n65 sl ` N ,=; R� .•V 1V�l I . =r 2 2 1.:j T0 ti 9-n '��R•',,y =-Ri-v cr:<- .-rz-,r-; u; ^^m- — : :.3r�3 ",x - 4 ;. "P.�ddis *S'" - n^ -,_:,.:;. : "" z.h.� � , ^- ;°.- i ,� �•,,".; �, � qex,'_ '= $4- Z4 4 ;Moderate ste am km 36.2 RM 22: c �,._ �,b'� LS`.aa. .'•._.,.,.:;�wa,..at.?i'.._..s. _ ., .. ....:...2]:ku.'',.'.L -.`_i "_i ,.'- ...',.�'...'...w...�....�_. .ii.wt..e<._._.,.a. {_nu�:u: ':.:.i.. �_•.aM.iS�•z... h,.f._, J.L U �. .�_..n.u.��,..,_Y$.si ia..- ,:.+a,1nY...> __ Addson'-SouthVWTP,'tia North Avenue.;" -F. t; t ` f ,z r _ : Uncicyeloped K.t.y t9o. :air Y sE _ IR M: 20.9 -RM I9.5 River km 33..4 3.1' 2, ... a'LL �' - r ,..n arian zones <K` _ 7...r _ate .- cT,__� r, fr s -,s- �s - : -- 7-Z7 --_. -r,-- ~__ ,. .,y _ __ _5 i -1 „ �'�l.N' 'd°'Y:- .:.'�"ry:::`- ' o. "?.L , t :.'i r _ r'i _ °£' -Y _' - _ _.. i i•' - U�,;k.�, y'. � P r- �"� �U z+ # -� ;• °; ^;` North °Avenue "to'A uie `' r - 91(Fair) Charirielized RM 195° y °`I8:1:;:River.km 31.2:-' 4y J f - ``- "�s'd,n.�_Si "� f L«''��,,..n�`=,•� -�~u€+ �s_-},,... -.''__ °:4,' �ca�. .T' °'•xr.:.,..,>'�s..»..� -'_,,. — — �'---^�"-�r- •�r'+°+�. - __.,._ ____�- "..- ,z-- -��.. - ,.-.� a=,� ,r-': 3- ,�r-,�"; r- '�^�"'�x� - "�r�,- ,M;;: -�..; _ � z,; --- '^ y rc =FF,i %�° �a "sum., °_' -" =4.E .4a .-�- • i. ,n sfi + ?�7'>>`, a `•r ��'.� y;, -.'-'� ir:;� - st ^d� " ° ", r :, %.� � � :�cy+'r „FY `A"?• - _ - P`, �v�{ yin -i ' r' ��I1linciis= Route�.83r�to�Ill o s -=� '''� -; '• _ ,_�_.� °�;Poor.�cano + � %�.npanan�zone��, j h. r =' yi � 'a y,.' • t{, pJ- 'fit -., � & :k,? <'> �, ,1 r,.��: : -x vs, "i":n --• :`'h� �'w '`c' _ '�.o- -��' '�..g �4.., `�}�. <m s, �, ^ }: ;, "'rP �'c.°__7�aC, ,.i42 ".� ,, .;<` �,f'� :'. 'x,�;j ;; �e. <,a,`�y.,vt :. �; .� - five km 29.:0:.+ �channelzed).; 4,..�...x• "'•, .,z' . I i tir �- Mme, d:i +.. ,d'a',rw,..1J.?+,� c'�;�h:ai•%.n� i��R�""�.+�,,,r`. °,`c'4h.. .z U,..'.�2,i' -,�,.G �, ,_..'.- a..,.<..�.....:u: -a..: ` ifasl ..a....aii::......,,:.s."sna ?,n..,w.. 5..... .,:,= a- "�','.zi:`:.m`'.„x„t:C.c n'm,.sk.,`.t:. .i..;•&."si_"_mo x.....�, su'rw,`,nr u:..s- _;.rescm .r..'t. e..s....a.uu,ax.., .:,....;..r.<,.._ .+.,. °T.'�'_'9:3 1y'�- -�"'^ .as ...v�.�,°'w^.�,,i"k-"i-•rR��'v -'fir ',r is -s- "d-.r- ""r+ -: r.�. b,rN `a ^. ;x,'Mi'!R'`'L i,'�,��T ��'a nwxr�i ,�:; ` ._ua�.:.., '`� � •,;y �'u''- oSh' ?.. a• � L ,� •.erv.K;, :srs, Y n�; e° :�'' ` � r1`8,.�ro° F3� �e � � `�''y�?' Illinois Route t,P, rf iabitat. d versit -scattered._' W- `q li �' •t1 `:ti' `�`i.; �. sR,rx "tn ;i, -,2e, ._x: ,Jt ?w +X, *"ta i*�a` ;Z �' �;,, '.`�4's= _ �. 3a°;4:_ _ e, v,� 't,'•t e,t r «i' "+t•,''"'1 �,.�. u!•�+, 'w�1c£[(al ° "'z;, r'd :;� " "��',t .1,,;.v: " °`�'•�� ';--- .,. ,. .-at�:- x�:-.,,.,.,r � _-',-w.'. . R>: . 1:.Vr_..Ir,'_,:.i...t_qI.;:':.6:+.t., : . + f�:�+x.�y1 ;-,r;� i + - : ; R_ ' «- ,'.x- . M `.w �i y' ' ¢�-"; Y,1z '.;,z,i� 4. '+v i: ;.e`�.�r -3` . .'` ^ ,5 * � w' ' `aRy`.F.: .`zi ? .'s.-v."., • "� -e., . ,.r.,_.i....,.ry k..,;- .- . in...':_r . ..c2,. "- _ .5. __ ,.= . 8 . "s- '^�a. ; 2.;.::21.t._z:.,:9 y.. a°-'°^.,*f c' ; mt.9 . m�' '�' � j;'''I.� :,' a, !,_,�� a , ... e _„�k,,\ .: � ; ,�: w��i,- � u °>�;NY_� - ` x ...} � I ...; ti` c...! a _,Eri...q,�t o: �>�nr,`�.v'.z.xj - ; �� , d�e.�e �,., � ,� ir n r�^.:o` z°'n x4o <, --: 1 � s,;.._ ( _ • ".g n e .a_rc,i� q .; i ann , ':x.•:.we' F•s:l..ii; - tz ed� ,` ` .) _- ov -7r-zt k a l f's _ a^. ' �• -- :r=- -"„--= L�._. ��., �,�q -'--,- �T'�..__;.- � µ�- ..- c•t� °.r -��'c^' -' i r 4 fit' av;'- t. r-',.. .. T�'f ° _ �; ;€`�°„ � �,r- rz�,•�,r,'°�. -,•_- _t.� '�'"'`�*� i -�My Interstate RciuteF$8 to Grave MiII Dam':-. r s r ;,vPoor'.$abltat „diversity;,._ -: u'. , 5 `5,5 � (Poor)Y Y,a ,k �. t F> ,. R1VI'14.3= -RM:10 7 , -a 6f,km 22.9,- ,,- , . :� ;g.- :scattered y . -- ',...Y,�_.:,_'•___._ t.u.....�'.�,�«�.�..,_.._�. ��` ^U.,.tY'.�,';.s,�� -�:� In addition, the qualitative habitat evaluation index (QHEI) was determined at eight locations on Salt Creek. The QHEI provides a quantitative assessment of physical characteristics of a stream and represents a measure of instream geography. The seven variables which comprise this index and the best possible score for each are shown below. The maximum total QT,I .score is 100 and is broken down in Table 2 -6. The Salt Creek QHEI scores by river km are shown in Table 2 -7. Table 2 -6 - Qualitative Habitat Evaluation Index QHEY' Component° :-- r= -- �, --.-�- �� _- ° --�- -- -- --:-,•-. �r- ^- ,_µ,.Y..- ,- .._- .-rz+•- - -v's` -�_ `- -•�.iF ,-e-, -� r5."'; ,i'�`r:t ...JS 3 �Substrate.:��% ;e':and�tQ:�ualit� 20�, � °�. .`�,'” :_`<t°.��t - rs�.,: =a,; sA,�,�,-.�, `.� ,:�'��.'" .r�• •L;' � }�`�i�`sn:��,� ";,t:,,��, '°a .:k ",� :,' dc., �'. ��. ra��`' F' e.. s''`.' e�.: °,.E.'-'�R,...:.�..'' ",s_•t.;.t 4,u;'i_,...L.'_`..2 .:.n,: s,.:S,aak.. res.-.. a;::.. .,..._:.z::�.:- >vwJ.�,u,a:.u�'• .'_.. °�: ,. �,: �.,_' t. c". 1;°:�.:a.:.,..5,.r- :'•'�''.�F,: c:�. ..4_'zq�u.ta.._:a�_a�. --�:J� ; L;.:.t�.t.:C..�'; I. .___..... _ .,Fi: -:. �,.'Aa o-_, 4' rz.�, �' � •'r »',�- �,..� `' tream' cover :�� I �Je ;and �tamoun`t' *N,1 �a -t • U.s ,aw s a' J .. .v" i'" c. �h_yti °� uF -.. sa.,=,�° ,,t. ,v F: o s+.,.,� • r,s °ZY� s _ >.' ?r3,3>'.;,'Y _•� <'•' t>�. :t,, ,,n�° }� '4!3' • 'C�rva,^, "_;� �_- .,i....a..s.:.•�.&_: S:ru...+'u- :..a,..a.. _ ...,..°'�:..`�wt ,�" S.:a�r:..::`x�,�°usrtLa'.r.'�i s...a.X.: .,,.r: ..a.- :.w::.,.._..:- '�::5,.`•,� �:a,okM_.i , ".�n,:s=.,'r,:."` c�a eS.:ia$ &..t � L�:. "w. ter.. "' „'tl?':X�f -; -` ,':`yam :'„'<¢3'fv; "ur.'*.';'e° -_'p 3 \- '."""'`F "'F- e'a';t-- ^:•9 -�- ^� ;^�«.,a.°^ „"^ ""' :?F;., :s'7'"'.,- ...7- r,�.••I\J"'r',- ,a. r'. .'"%'.5 -r �,��' ,,�., :,Y ",,N, ar, ;�r' 4`•�, �' gab Channel mo bolo s riuosit; '4 d ielo mentAchannel�ization `stiabilitV "fr �% �', ¢ , . ` rs�, " R,•c."'r taa:r�r �;, • � 'a; <V�/ "s; ,�,`,'� a �. •4 a.s "tst:.`�+ - ^`),, •�,;�'..ts r ��° "�s:tt.,;:t; �? Rq, _�{� fib. x %7 ' Ji `',::,. , �? ,.", : � 4t�,x� Vim, •,;n;�� ` �� f,: ;� rr' i F,h,✓:€ '," ;u _,r�q;�,�'t,_ � ,�'�'�;', -.-' - °� e i �_ 4 -F • s- '- """3;"�° e- ..-- .- .GZ-.r � � - r._a -..-., -�...J ` yr_'� "._" e.^ i Ripariani, zone: `width `';._gcialitV ;liank ,erosions = As ^_ �-}*,,;'; c'_'^'>-',,•- r- m�.>^" �':`•- r°, �-`"-,''-;- w- i".'.- 'Y�- •,--- �..- +_"',"r"" : z" r"."'M1';"'";=" �,;';. F_"`. �- �• sv ".ry..,•rr,^`r'Y,^,.°„'°`..`." r-- Y•n..:a- ,P•s,'. �'� ^��::�s ;��...c:,n ;y; �•c\- ;*--r- `i'� 1{ o ,.s<• � � ��Poo�r4 = ualrt. - q�maximum`de ,th= :�mq holo�� ,�.currerit'„ - � ' ,� �� ° � - �,�� • 4• k, ,� ,° ^:�,: �'., - .;x �> w. >t ,�,7, +51 "t..'�� >' ,tl� ; x^a'S•h l'._,;. �_ . e '. �`. ", _ ';a....,� :.. _ -?; r... � ..._ r•� ',..+tip' °.e»>:f 'm : _ .:. c-..�5 �.�...L,.,,;s..�:.3 � ° s._.. -._ ..:3,�., ...:.C....:.:: _ o.�.z _ .- ,.�'�-�? ?u..,c�.€�\ --i. i=:' i1 .:: .. __., .. �_ _ _ . . _ _ _.•_• _ _ �.- ....q..,-- � -�..v� i� „�'P��.�, •-..,. _' ,..tea., - --- _"_^'"_ — <_ u�,` `_._• � p.° %= �A-L:- s._ _ -.-� Rifflequalrty� depth, substrate, stability ;aiibstrate�embed�dedness::: "ti =� ,r�__ -._ - - - —.F� _- r , ��_ °".,•' _ "J-- - •--; —�.. rq`_j; �t;c.4 s-m ;x,' ?',r4^': ,€........ -� ✓r.' qx ' ;.'� -� W "y -iq,7 r,w•' ^' ;q'v�? .. -,y } °c "f.' 1,0” ,._ Map gradient:4.y'`° -1 =•'. �° S - 4 SfL i„ - Jiv - .t, '., ='�l.`1 =y '`,c� +S `?!`.F }, k'W:.•�`„Y iN, to .�,.�w "., :�"�,�.'^.•u�:l'''� <= �...:. ' C• M >��.' �> = "< , , w _. �5�..��.,.,.= .�'3'i.... DRSCW 2 -12 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Table 2 -7 - QHEI Scores by River Mile/km Rwer:RNI/l ; QHEI'Scoreti:_ lab 27:3 °:.4. 8:3%29.53. 31'6.=5/265 H 13.7/22.0, RL 2.5 Dam Site Investigations Removal or reconfiguration of dams can increase dissolved oxygen in waterways. The three dams on Salt Creek were investigated to gain an understanding of their characteristics. The names, locations, and river locations (based on the GIS model) of the three dams on Salt Creek are listed in Table 2 -8, and were depicted in Figure 1 -1. Table 2 -8 - River Dann Information u � � a eP. -' S •.- • z _�F • :iF�'�y9 Y,a <�3'_.,., i��c4t The river distances reported in the above table and throughout this report were generated from GIS data for Salt Creek, supplied by DuPage County. This GIS model closely follows the existing stream centerlines, and as a result, is different than river linear units published by others. The length of stream is critical for evaluating water quality, so the most accurate representation of this parameter as generated by the GIS model was used for this study. DRSCW 2 -13 June 2009 ,4 =� �� Bounduig�Bri�ges�f,> .. �r� �`� � ;F�, Nearest: =�,,. � Year' r�- F. -., x a kni' Built .' -�� -:� Vi stream' Downstream: Town . °� ' a M 'G_oows ad i 3 `!' ,s' • h _ .`- . ' t. <y: Elzaeh 22:9 / D 2 9Q N�a; �.'�,"' "'5ne rse.Dam i oiei'.....s�r__...w,_..s_• .vC��x 1 _ -it�- W:036.8: 6 }e'a . �.=:4r .��..7�..__, _•"� -- .`.k . _l•_f _ _ �^ _- _ _�„ _ .�.,..f .w_ .__: .`— —s� ¢.. Fuill�ersbul •_ • =lCT �S x'.3 � _� ;t. `; mot'= f' • i _,,c zt -.s�. _.,mac 'gn:k.#. - ,v` tom•-'^ - .t 4 'a '., .a: _ - __ "'_fi=t �{.._ ",. -•. �'�tF .,��. I _`S�"7 i��W'4 C ,z Old«Oskbrook � Oak-- okr+ f o B .' tr,odsrForest ": - f' 12:5/20:1" =; , } : 4 =- 'r -W .66k PreservenFoot.....w�:..b ` L' '— ._ � - `� j < . <��I - j .,, —'.,..--_.. �_.....y-.'�...- _....- .- .,r-'"' f r•' �, -1 a' � ,• Fly `H '"h,'3: �, Fullefsbur ,�,r,= .,x..;.Y :Crraue 1VIi11.Dam -a 1 Woods Forest: , �� ° =t .�._� _ 10.7_/1;7:2" :::`.� , ; �� <��York Rd�r< OakBrook,. Ful "lersbur `�° Preserve' Foot'' L:<.. - i R 1 P ,t .{v.£t • s4 �.a�Y�.'n1y..'}�.�`� c 'x� �fi.j " cM 4�'` ( ��4"'st - r'5a.. S ...i:� - t L� i,..,..,A} . �, � ;.� i� .F'r,:� � \. -` .11rld•V� VN"- .wr,?� S ^ \.�.�.� SL s,TS �','': "H't �l 'x�4�' �...�� Ra �. �3'" <' °-`'a The river distances reported in the above table and throughout this report were generated from GIS data for Salt Creek, supplied by DuPage County. This GIS model closely follows the existing stream centerlines, and as a result, is different than river linear units published by others. The length of stream is critical for evaluating water quality, so the most accurate representation of this parameter as generated by the GIS model was used for this study. DRSCW 2 -13 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions 2.5.1 Oak Meadows Golf Course Dam The Oak Meadows Golf Course Dam is owned by the Forest Preserve District of DuPage County. Figure 2 -2 - Oak Meadows Golf Course Dam A survey of the dam and channel profile was conducted as was a characterization of the amount of deposited material upstream of the dam during a field visit. Joe Reents, the Oak Meadows Golf Course Superintendent, was present on site. He indicated that the structure was used historically to facilitate the collection of irrigation water. However now the course has constructed a gravity -fed pond to accomplish this task and the dam is no longer needed for this purpose. The dam spillway appears to be an all concrete structure. The structure is 30.2 ft (9.2 m) wide (between abutment edges) with about 2ft (0.6 m) of head at normal flow. The abutments are 2ft (0.6 m) thick concrete walls with a mixture of materials used as fill. The dam appeared to be in a slightly degraded condition. The left abutment facing downstream was clearly leaning downstream, and significant cracks have developed in the concrete (Figure 2 -3). Previous measures had been taken to correct the problem using reinforcing steel tie rods anchored to the upstream abutment wall. The same problem and mitigation measures occurred in the right abutment but the wall did not appear to be leaning. There is a 2.9 ft (0.9 m) culvert pipe located on the left side of the structure which was clogged on the day of survey with debris. This pipe can provide the means to lower the water surface DRSCW 2 -14 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions below the weir elevation of the structure, assuming the capacity is not exceeded by the discharge of the creek at the time. Figure 2- 3 - Left Figure 24 - Mature Tree compromising left training wall DRSCW 2 -15 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Figure 2 -5 - View of left abutment and culvert, the steel gate can be seen in the upper right An investigation into the amount of sediment upstream of the dam indicated an average of about 2 ft (0.6 m) of material in the channel. A total of nine cross sections were taken beginning just upstream of the dam and extending upstream. Detailed cross sections and locations can be seen in Appendix B. A profile of the survey through the structure is depicted in Figure 2 -6. _: Sa 1a�..�aa`,�t..`s ai� 3i` 3°.'.'> i�.` s�``: :5,tyz`t,..3�_?:y..i.:�':..,_°� ��..�..�aii''�f;.s, .°"ri_'3�$, °"v" °>S_:Y.'x'� °y •�a.�°" t._Y��O" . s: sa4. 1.,�1K Oak Meadows QC Dam Profile c. 670 a a'r ? :u 5 �M Y. "j; ` 'o." a. > �_ S 'a: tc 'ao$ai„�,as.: _ .'c ��,,T �h..a \°=�. iaro a.�: M •; a� ``� k. e a > .., Sf�.aii.�;SV� �a%, 'A¢ `�ms'.,'re ' }`�'° a. r: \.r.;3�„ Sv� `3` �;'>Q Vii �- '��`•2„ «:F, �,'. `>'n�`�^ �' is7: �`' �e, fy;wr,��e.. :�T. +r�'y>'"�E�•��t `�y..•�� ° . 668- ., r,. i . "m:7• `Yi: e•E'1r e+, �u t�++� •4.1,.^�R,i b'.MZ'e'4y� ;...f 'q<'•A S`, ;'� T� i .F� "A }`, a• '��a .y �j h¢`21 - p i`•c_.., ,s;,`, }Y., S,- :,�,.�,r!; : �.'i��"3`° '{•�., z 666 p V R. %i� ^''�,o. S...f"'. �X ie 3.'. d� �. "�C �� F "•��2`�' ..`.'tw�.. A. g �QS` ,x�o''Yq�tti''�if,�R,�i. N:"� +� 4�5. '. i .' n . crest EIeV W ! HC1 F i i^ . ni'` K a ✓. " M V 3 k [ AG, t, , W , S'¢ . w' >i ? tt' J Ll � ¢�\ � � - �....�v }Y�,' y'} ° 4 . r,,ykM ' . k o '�35,` °...+s,,f .. .;.��,^i•4, '�`' ,\ -�Yt'a ^�%S`c "s _,i.ASSn"."'Y- F, ^s- -,w-.� v€'� "asd '.� 9�`•,k'4 `^l' a� '. 1; 9 { S` � x'i+,- t` Z �R z t °,. .5'. >� � \�•;.�Y'c � � g..` ;$i i ">R �Q,,.,�. �; �- C `��` � `x, �'u `� �ra� 'i�,i'� �', t`�l" ' � J —* —Water Surface Bed Surface 2 �'S• ", >i'-s 4?C d�'a t av+�'.. 3r'e " <io-V'7.+*'iJ3. T..N •f' � ` �/ �� `�1 " �� M.o- • f � . . . \� . f " S 11 ".h�' • 4',t\q,� S., �t o ��M'°z' �' i x 3 T da:' , .� ~ Depth of Re�-3 sra8 gaf'e s. >' `.R,. ", x, °, .i,,; :.. -„ °z y".k -3.�, �^"',$ >.'. ,'io- t; a"A is .�e �'F a °" • i "c • �G,"r'.r d.., +r iii' Y, c °ttjsi," 4 "t • ;, '+'e' a.,,. 'L °fix; v* .. f ai' '," n�_ , g,�..,," n `Y " .i,°A .k%.{ '.`i _ _ ya.`,z,, N,'`t:• ¢ '' ' yq,�se ��".i' 0 656 0 200 400 600 800 1000 1200 1400 1600 1800 Station (ft) Figure 2-6 - Water Surface Profile at Oak Meadows Golf Course Dam Sediment has accumulated in areas of low velocity within the stream and is not uniform in its distribution. All of the material consists of semi- consolidated fines. Storage of material within the small impoundment is still occurring as evidenced by the deposition of material in front of recently installed A jack bank protection measures. Because of the low elevation of the structure, the hydraulic impacts to storm water storage during flood events are expected to be minor. However, at low flows the dam maintains a fairly constant DRSCW 2 -16 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions pool elevation upstream of the structure that persists for quite a distance because of the low gradient. 2.5.2 Old Oak Brook Dam The Old Oak Brook Dam is reported to have been constructed in the 1920's by Paul Butler to maintain an aesthetic pool through his property holdings during low flow periods on Salt Creek. The dam is now owned by the 'Village of Oak Brook. Hydraulic studies conducted by Christopher Burke Engineering in 1989 indicated that the dam provides little, if any, mitigation during flood events. Further, residents report that the dam frequently becomes submerged completely during flood events. Figure 2-7 - Old Oak Brook Dam Removal of the structure was investigated in 1989. A letter from the Butler National Golf Course (upstream of the dam) indicated a desire to leave the dam in place and preserve water levels through the golf course. No other discussion on the merits or detractions of removal was found. The original structure of the Oak Brook Dam underwent major rehabilitation approximately 20 years ago. There are two main spillway components - the fixed elevation spillway and a gated "emergency" spillway. The gated spillway section consists of two steel vertical slide gates DRSCW 2 -17 June 2009 �cE,�� %b "vi* t��'J •� �>,+�� a�! fy�el��Lj¢ '3+'i�' F ;. .��a .e 1 r 1 ` ➢ 1 3+. { 9i '(f °' �`!', ] 1 1 {eI� Y K�.'F� Z {. i it }.v3 1 ibir'.b fii s <p�� '� w� a Sf��,?� � 4�tsar r�"!r''. �i `•"+�"� �:�y E� 'qtr � 6;.� f r4 ' 1 �� TT�A l�-s.E;.' i J j{�:.� s' `• ._ ? OL �N �� a~rM � � Yatr ,�� `kd`�•r�k��" „rte '-s__ "'v ••:..••••'rr '�`°�R- ' -�'"` ..s _�= r _ w - _...'s""'c"X y � 1 � r I i _ a., `!•��' ,y� � r °� r s ` M;.r 4 `� s.s. Figure 2-7 - Old Oak Brook Dam Removal of the structure was investigated in 1989. A letter from the Butler National Golf Course (upstream of the dam) indicated a desire to leave the dam in place and preserve water levels through the golf course. No other discussion on the merits or detractions of removal was found. The original structure of the Oak Brook Dam underwent major rehabilitation approximately 20 years ago. There are two main spillway components - the fixed elevation spillway and a gated "emergency" spillway. The gated spillway section consists of two steel vertical slide gates DRSCW 2 -17 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions rehabilitated in 1992. The primary spillway is 65 ft (19.8 m) wide, with about 3 ft (1 m) of head during normal flow, and consists of grouted stone with a concrete cap (no information was found on when the concrete cap was applied). The condition of the cap could not be determined on the day of the survey. Areas of the grouted stone spillway have eroded on the downstream face, leaving an irregular geometry. A report by STS Consultants indicated a concrete filled fabric - form mat had been applied to the upstream face of the structure in the early 1980's. The left and right retaining walls consist of grouted stone and reinforced concrete overlain to a larger extent by concrete filled fabriform mats. Seven cross sections were sampled upstream of the dam to quantify the amount of sediment upstream (details are included in Appendix B). An average of about 1 ft (0.3 m) of material was found upstream of the dam, with the largest accumulation just upstream of the left retaining wall. It is not known how often the sluice gates are opened on the structure but sediment upstream of this inlet was minimal, while downstream, fines had accumulated in the sluice gate channel. Most of the material immediately upstream of the dam was cohesive fines but the sediment quickly coarsened to sands upstream near the 31 " Street Bridge. There was not an excessive amount of material accumulated behind the dam. �� @�!^ \�,�:� ^i�4W \�h*T'1�.` ?i �+':...�. ;, A sy,"..�; 5 ^v �t ^.'"{�+s�� a• >m� yr 7 3 � a.'" n't1�`.i'^,^+. . , ®Dep9�ofRetusal Ofd Oak Brook Dam Profile - +— Watersurfaoe 'a Bed surface .f � � 650 .� '.3 ", r�`i"\�4 °l . .•�... 5` ��` ""=�� .'ro^unali' tul ,. ^.� ^` S�v ..� \'. va ^`x�.a>s,` ^"`Cx V'..'LF , �. ,a 649 � >�l� e.�x•:.° N N.� � � - r. \4 ^s1E�,z '- �s c.. ^.'d " .. _ � m a s r 648 647 w 646 C ld 645 > .1 m 644 W m 643 �F 4 642 ¢ 641 640 0 1000 2000 3000 4000 5000 Stathn a# \ "I �� 'R'. ,. H y."- s""�_'�. - "°. -4x' � d - m+r.�q-- -•._.� , _._ , ., .w� ", �^ ._w , . � � , .. _�� ',.�, � � �:� ^.,� �>R , „� �;� >��;�'.,�;” �.�;', *'' •'� ® ®Dep9�ofRetusal ` � _ • � �� Crest Elev. 648.3' .f � � 4, �' ,as.`, �,>� -N;vt � ,af °0� r4 �' � �• .;s Z`.,¢ - �z:.•h 'k � '.3 ", r�`i"\�4 °l . .•�... 5` ��` ""=�� .'ro^unali' tul ,. ^.� ^` S�v ..� \'. va ^`x�.a>s,` ^"`Cx V'..'LF , .r ro � ri • i"e "� � >�l� e.�x•:.° N N.� � � - r. \4 ^s1E�,z '- �s c.. ^.'d " .. _ � m a Figure 2 -8 - Old Oak Brook Dam Sediment Profile Hydraulic computations compiled by a number of studies indicate that the backwater effect of the dam stretches up to approximately 31 't Street during small flood events (less than 10 year event) and 22nd street during events higher than a 10 year event. The storage provided by the dam is minimal. 2.5.3 Graue Mill Dam There is no information on the original structure constructed in the 1850's at the site. The site was purchased by the DuPage Forest Preserve District in 1933 and in 1934 the Civilian Conservation Corps built the existing concrete structure that stands on the site today. The dam has a crest length of 132 ft (40.3 m), standing 6.2 ft (1.9 m) in height. The purpose of this construction was Power Generation. A side stream mill race is also present, which was used to 2 -18 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions house the wheel at Graue Mill. In 1991, the Forest Preserve District retained Harza Engineering Company to design a dewatering gate on the North side of the dam which allows for periodic drawdown for maintenance and inspection. Figure 2-9 — Graue Mill Dam The DuPage County Forest Preserve District gives a detailed and exhaustive account of the structure of the dam which is summarized below from a 1991 Maintenance Plan. • Concrete Spillway: The concrete wall is 2.9 ft (0.9 m) thick supported by a 23 ft (7 m) wide concrete footing. An 8.8 ft (2.7 m) sheet pile wall is installed 9.5 ft (2.9 m) upstream of the concrete footing. The walls key into the earthen abutments on both sides. A 10.2 ft (3.1 m) long concrete stilling basin prevents erosion on the downstream side of the dam. • Earthen Abutments: Both abutments are built on a 19 ft (5.8 m) thick layer of hard clay overlain by (3.1 m) of dense sand, 2.9 ft (0.9 m) of hard clay, and finally 5.9 ft (1.8 m) of topsoil on the North abutment, or 4.9 ft (1.5 m) of topsoil over 2 ft (0.6 m) of dense silt on the South. Tests for seepage conducted by Harza were negative for both abutments. • Mill Race Channel and Sluice Gate: the Mill Race is 10.1 ft (3.1 m) wide by 210 ft (64.1 m) long and was used to power the 18 ft (5.5 m) wheel used at Graue Mill. Water control is provided by a sluice gate. DRSCW 2 -19 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions • Dewatering Slime Gates: 9.8- 14.5 ft (3 - 2.1 m) wide by 3.9 ft (1.2 m) high stainless steel slide gates comprise the dewatering portion of the dam. The gates are housed in a reinforced concrete structure located on the North side of the dam. Eight cross sections were taken above the Graue Mill Dam; detailed information can be viewed in Appendix B and summarizes in Figure 2 -10. There is generally 1 to 2 ft (0.3 to 0.6 m) of deposition along the channel margins with often little to no deposition in the thalweg of the channel. This lack of material is likely due to the impact of a dredging project accomplished in the late 1990s. The channel regains its natural thalweg of coarse material approximately 365 m upstream of the dam. The material that is being transported by the stream is depositing in a point bar just downstream of the final bend in the Fullersburg Woods property, starting approximately 700 ft (220 m) above the dam. a�— rte°__. - -, p �l �- . ,l c t _ _ ,_--- �• —."_ i . , n . �. � 'i�'.,�, _ �. .� �� , �'rC'�' ,ga-t �-^ -sue � . <'�t� P,; �,� '�`ir��,.T_' '�'�._, — ��,a?,c�,,_,,�a,,,.v J w; Grae Mill Profile 644- .°'' 'rc3'° ,1' �i ° . °� ,, t ,ar ... m y v a'P. ,^C +�'3..,rs e,:�y"'4 ,'a ., ,2�, ?"`a•.%¢� er.t`F' "k �t ^.�., :tn'1�.'°ci 'tF't�,ya„fi ,�,,.y`, +i,'F,e. r �l raDJ,k3•.;)'A�•n,,'.,nr2�LL%n. kr` ;. .'7" §, ?. $'k°',t* e; 4 - .1r4 Q* 8 W•`•YW ! 1 ' yYRya 1. 'to'.td ur "S}'h'.„w'.l '"�RF'�'y``L?C,rY'i'Y'G r�i`.C, _". L^�c�4.`1"a(9+Y�bi�*t�'',''k`rM1 i6°,,.§,,�`i`�'n',',,.',�'i A{ ' ZS 1`h ♦ 642- ` ,a^ f S.k :yk N '4e �� ti � i" - ,N M`�.'i% ytic$ `y, X 1� .'W i }l+`a� ` .£r 'V`M.` �'9 'A 'i ✓ A� "h. r, -.. 1 3^e k ,�L ,'� '6m y 'i' "4" FC ++`9:i�,'mh +gib raY �{Y, ay a:;° ya,an Iwo, 1'c`. w t. �'. x '. ,Qest Eletit 64'L.T ..��., � �° ` � '� � �.��,�`.- �,� .� �'�� °s `e..,.'. "�at' ,�' %'�r� � �,".fA.w �,V' ,e'�cs•�., 1 kt�e'�.; ±a� � 5y`. °K� J 'r' r'.. N x3�.�iii'',�....a�a��h,. �)ka,3�• i, k f5`,.+ .`�', ��.a �R� �Ty�« s+'hC ��((�1 by ,�ma � ,m .�':. 6`0 g` „^S ,+�,y '�,� , <MA' `. ,+ a,d +a�J�,h§a��. }pia ��'.�',2�•.. h. r`.ykL ,kYK �s�n 6 . � nq `'4Y,, "i3 "6�,11,�" "tJf� Y `.',Eiti Atk FIL +. ,s •3` r�r :'y d Fm n��' .`„'J£, a.a F" �iytu, JVy��''• u;v f'1? <r�` �..a4`.a'a s,3' qp�'� "i ^k�"q a'oc � �.: '4�.'a.,Y�� e t,,;'%� �� r:.�ex, �;` �`, °� zv . '.r� r a n "' K'.L ,,,,R ��, b H .+EC,aa;_,`^ `' t�,.'�`en`w`'� ` z'd a ., o' i"`>;t' ',i' ✓iP' ° rs',a�i, -,`1.° LM.q o,•' _° „'? .e�`{ .e';r� s 's,•, 'g :i4, >��i, +§ u �^.r �'.. .'cry,," '�°� °.,: �+�+,lk,�' dt:A,.�. `3• `.>\ &), F�� a'1 .T a,a.: . '.A•Fi�f `�t'F.• .Y�""��,r ,tA. c�, �;i,n. %` J? 'a"'� „+�.:E.'.,�, 3 + a• _ �� ' aftt ii � e° i °,' ." yy„ 2w,' <& r E yk� 2 � ", `;�, §`.n ,' Xe�' '�zr t;= =,• . � �.. ��'4 y^aV,. '� s,`;tFi 'a° ' s e3=A "a. °., :§ do..`��, a _F $i... SY D�.,: ��" k.'t ...-T. .�..-&C'.....'^ �� ,. t n` S: h, Via. ✓f\\ 'YM��VV�' \, .[w' _ C 638'� ;��` p�1'�•Q„ aY - �. `, ih""y,• ,`y,`r Fr, .4d;K ,,pp �,�� C'�'S'`�,,,a .8'�''° !t` ,S`,y,r; ..4i „v."!,a �''i' ,, F: �a&'.�,�o-�y`+'- i' .,�pim�a f 1, - "'�ys " *�: �,u. ^>`�' ',v�`�'••J, x.. e's�.rF'',`,{, �' aa� �.' � yap� ,k^ ,`./> F °€ t ,., e�,,'i ?y � .emu s. ��yl � s>"tt'§``P+.”, �e �A�`�'V: "�"�o�,`. .t��',✓ ' ,n `R�,H �'�:r'��”. Via} ,a� M1 e. , �yt ,•wti „�n °p•• •`�.`.�.'�✓ _ :n.�in� "T3 "4 ^` .:?z`e� RciM' ^S�'' h�, m+,*`a �s,^ �'��:,'?4,t3,3� `�'' <` .�,`o n S a,`\G'.. ,.r,.��,�?:- �X� +11`s�koa �ee5 Y^,, �5�, �«E.'.,9��`',A ";.,m��ta+$�`Aha f, a�. 2•�.w a'l��v'! >t `�,. ,�k` 3.,a, p� S;i,,T" ,- >a; „�..J L;?�F! _nAs. ,:.+ N 6.717 s ? . '« .x�'/ °" v �> ` ° ,s "t ' ? ,h • , �yg'r: a , M 3 °"d �rT<ad. . `y, x`�" "xy�''O`' �� • aaG1 .�ii� W /tf { `�" f%' E9 }' '� ,lk •• �''., k Y, ""' ^d °o m'.' .",.Y.6,�'' '� °`n ., .$:�F S u =k a! .1 .t� - , OR��1 634 VJf e�• =c .lY'f' .F ` 1( U "� ~ +as m',a1* , ��.y y�� 632 `R , `W , � ,. `t, h." =� v,a, ¢ y` e s ' �°£.' >�'±`ti�i,'" C``3�iY *+."�i >.,. y� • ��^ �:� X- j4, �C� .i• a'�.�.?iw,V�`:v \F x: � =�r�a��3 "�+�'`,' 3', 6+" a` ,i� ^Y a 1t` 'L; i^�e lti .p�C`^a"��, >,@y __ _ 630- 0 500 1000 1500 2000 2500 3000 a - "„P,�'2_02. `� .�"_.�T'_,_�F 's_ ^3`.� `��"c :c•§3 -�wst' ` \i �a4u�a��2��V'Atli..o *, 1': .Y°�� a.w- �- �..- ,.�.a,.- +3.'w�..a= "'Z Y Figure 2 -10 — Graue Mill Dam The hydraulic impacts of the dam reach through the Forest Preserve District Property upstream but do not extend above the Old Oak Brook Dam. The complete removal of the Graue Mill Dam would result in reducing the flood elevation by approximately 1 ft (0.3 m) for the 100 year event between the Graue Mill Dam and diminishing toward the Oak Meadows Dam, according to previous calculations performed by the Forest Preserve District (prior to the new updated FEQ model). In terms of storm water storage, the reservoir provides little capacity and a general consensus among review past studies indicates the dam has little value in flood mitigation. 2.6 Flood Control Reservoirs DuPage County Stormwater operates two flood control reservoirs along the main stem of Salt Creek, the Wood Dale Itasca Reservoir at RM 42.4 (68.2 km) and the Elmhurst Quarry Flood Control Facility at RM 17.6 (28.3 km). The Wood Dale Itasca Reservoir has capacity for 1,775 acre -ft (578 million gallons). The Elmhurst Quarry Flood Control Facility has capacity for 8,300 acre -ft (2,700 million gallons). Aeration of the water pumped back into Salt Creek is provided by a cascading entrance back into the Creek. Although not evaluated as part of this study, DRSCW 2 -20 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions dewatering both of these reservoirs during low flow-warmer conditions would improve the DO levels within the creek from the increased flow and cooler temperatures of this water. 2.7 Sediment Oxygen Demand (SOD) Field Measurements One of the inputs into a DO model is the Sediment Oxygen Demand, which can be highly variable as the stream geometry and slope changes. To provide these data, SOD rates were measured in situ in the summer of 2006 and at additional sites in the summer of 2007. Table 2-9 - SOD Survey Locations and Results WE,- ,q d", VC e S ' " _vM, 's, M t., A F,1T7,T A g N 4Z . , 5N M, IV'A�,'',' zO &C (,&t Vdgy),-7 e�,k, a p e4 T mp; 0 ^t'. km T_7717_7___� '17r V_ TO Ai:,,:�,, 77 -8, fl 2:066 L_�_AT TP U P Di -W W V A 1'3� S,dVth? D*,'Mea," [7,,Q` -7. rk South. W •ow� V ed ows f 4 S"Y owns e'a-fii"" "'Addison i'2f,:0/33'S16 tt M "at Ful ^'' 047 a D6Whsd&ifii.bfN6r,th�'A e. '1k, ' 9 %3 �&"bf "Stfd 4, U-g zgz - -;�m W, p E NAN- ,, Pw f2 6 'f 'n, % 2.3'1 77 17 774 qT r:�,12.7/20 A ,4,_"3 St 7, IP-T st", ,. +^ ` St 200T f3 `5720. 1, ,ru *_K 4t- abby e'� 0 ld Bfo "'N T71T_ A Q1.9 --6f 3", -,1,St,, _41 I "" _ :_ A, E Ww 'E, V, e,A M, 471717 1 1, •71� Cfe -0. �q "2007, pnngl,, -J 19.6 f r4jad):,_ -0 DRSCW 2-21 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions -"er' nFe_- oYoNoitha -lrsbur g ,Wdsvl�;.3;� i?r' t r Inripoundrne t _ r _r ML73'�e.'2. t7 --. 41 ;�:' '17...t., T, j� x'4 ^ " `'- ''r5, � ...i.. � `s. !., ' ark.,( �-� ~.A 'e''.¢4 '- c1-3k it .�i` =v iov� 4. 2006`T :n � , Footbnd eay�tFullersbur u.' dd,e ,. , . g f- E ti {c- i , 4" 1 7 Q r ..•5. � d's', n tun �" ian ( ,U"'- ,.�.St.� 4�a f , I 4i;,oc P 'i=:.s_ R' ( vT�.11 .:�}�1 r,'I /' _ , .,t „+` `nw; 't .. w`` ta„ .,i .., ' a 3 •Y: `.`,"�r+•�'= '.(� , s:f.,�+ '''� e.v�.tN#`:'�us�. ..,.n, a5 <n,g.°• -' ;r "y a'�"d t. µpr y�;, "' -. Woo�dS�en'`'`l''M,' �.. �.. '••;< _ ^ter fz, '_....u2 z....d,.,,_w.....'i.,..i;+�..a wt�..�.�- �_..�1u.,a2 - ;r^,*:��.m��:,uc� -.�� =x v.�"'.; ';�'ri;�.�.�W'^p`Q _`�_'�""_""h:��'r nr1" -�- Vie• ^-:r.�, e^,,��-_'�.-�R`xn ry - .,�'�:,'�; s�a'�Ms:�- ".z.�- •s- -,�<_; k « > ?cam ", -*'•` i w� , �. ^, s �.' .,4 >t Soutliernr,:Fu'llersbur�Qi� Woods,' �;� �=�� - ��17G�� := v :r:.Iin [(-'is- '�'�'�_-7 ",—.r, � •-- .r- ......,„.- ...�._ _x.'. -i ^' . _ _ ' �r�- ^,e^..,,� ^r..,r • �- x: c--. rj....-; t"° ;T"^'..- Mv�..- ,..�- ,..--- --- --� .;f �- a � _"_ _'- '+S= t��>`.,.. - _ _ - .,? �` . � �^ �� ` l� ` � �!. f r - - 3 i I . c}'ir.�.i�3 p �> *i-.S- x�rV�'e5'•'n a :'^ 'S ` 2006$ ; T streairi .of `Graue',lVlll r ...'1'0:8/17.4` ^: •f; F---," _ r ;• r, -° }".t";T"iE��...,rr._•"*`tn..s _ „`- .''".-- `:`? -:� ! _____ ,< :E „ �:*"”` -' 2007 U stream =Qf''G a "Vli'11 - ,, - +<b �sR = -1; 'f ',T„ �� stxt }�ri4� ''� °.` �r�n- • ?��,`3rE "-= 8^' ls. "A1 0.7/17.2 S'.: u18h. t_"- ,'s;`;'"'nr'._'`"w, i."''_",.V- , -.,,.j _ �. __ ".- .z-- .r_.�-;c„tr-, __ z �._t; -� �ar-� i•.�•- �''i r' � :�,`�rhit^`:r 9�.a?r`,ti 2u` 620 47, �oa w ", �*- ;"\,� �'%.:"'n�..5 � ? i �» -,— r- .- .-"'-y�r-r�ry�-- .- -xt';' rfec.�- •,,�.Ka�. -".-t .y..?�snT-- {""'"�.�- Tre -.,�t wrH^°, - ^c;a x; �r�-a�.�.., w�,.„;� s -�`. v`f � � .fi'aC �4��`�+aaa�,' a� �r, �_.�• Cu :'54 A Wide° hanneh northGof n\ S'? 3 ,ffi •. t, 51r^ �'i52+y�',- f•.F`' :, < 2'a ,..i� .. '` `5 .,"�• ,err ?�..,.,. �c, 1,a >: ¢ i :�ii< -.. -... �' 1 ..��r "z`ta,,`as�'�L:3.w•�„c ^ui - a�a✓.cxy,y;� ��,�;�;?�"� � `sa =,� � 7 ''� '. . �' ��:!�a,.� s,��r -sz�;= a•`f,- �`i;,, =^ - 'r � r^�, �` ,:� '� � rte. .5 ;^ . •r. °� _ S,' L^u,'.�_ ' ' ', A° ' f.,'�ry��y �.r n -- , c +,., . - =�'a ^ _� +.:r`,+;'?� �,=. ^w��:�:sy. a'.', -«a� L_`R..c� � - �.'A_,.�k.+...� Li. _ J 4`•__i.z - V,'` t�,• °�^ Ft�� " �, °' P ia.:.., . ., "�.,•tid,�,,�s ,.. ', .w .u.. _-'-..z.'�'_ z�^ ::��,"r'_Sy�""' . i"”` _�-"'._:T'�" - '�_ _ e� °ret: "c' -il� --•-•v , `Q((( -- —•._r� _.- '- .�Z-..�yaRc�,C4.� .: ' �N,s Down_ str�=Ee. a:nRt( sEas�t. ; 7) ' t .-si. d, e z' 'ofY'.ij; , .. t}-,•�k�. - �y_�z � C:ry � .t��:. , 3' �° :� � _- u . il `_.4 :'WolfRd�r� A bottom substrate composed of fine - grained sediments (clay, silt and sand) is conducive to measuring SOD; coarse materials (gravel, cobbles and boulders) are not because it is difficult to achieve a seal on the bottom of the chamber. High SOD rate is generally associated with a high organic content of the sediment. Slow moving reaches of the river are areas where fine - grained, organic sediments are likely to be found. When the field crews arrived at each station, the river bottom was viewed or probed to estimate the percent bottom coverage of fine - grained sediment. The width and depth of the river were also measured and recorded. The fine - grained sediment area was identified as a suitable location for deployment of SOD measurement chambers. Elevated water temperature was preferred for these measurements to reduce the modeling uncertainty associated with applying a temperature adjustment coefficient based on the literature. Field measurements were performed on five days during a period when there was no precipitation on that day and the preceding day. On each day of the field survey, SOD was measured at two to three stations. Water temperature ranged from 23.3 °C to 28.8 °C with an average of 25.1 °C. Table 2 -10 presents the SOD results for the two summers corrected to a constant 20 °C ambient water temperature. With the exception of the Wolf Road at RM 7.9 (12.7 km) SOD value, the highest SOD values recorded were in the Fullersburg Woods impoundment above the Graue Mill Dam. Elevated SOD values were also recorded above the Oak Meadows Dam and at Butterfield Road where the width of Salt Creek expands significantly, resulting in lower stream velocities and sediment deposition during lower flow periods. DRSCW 2 -22 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions 2.8 Continuous Dissolved Oxygen Monitoring The DRSCW monitored DO at three locations along Salt Creek during the summer months from 2006 to 2008. These locations are at Butterfield Road, within Fullersburg Woods Forest Preserve one mile (1.6 km) above the dam, and at York Road immediately below the Graue Mill Dam. In addition MWRDGC maintained four 4 sondes on Salt Creek, The DO monitoring locations were depicted on Figure 1 -1. All DO data was collected according to the QAPP agreed on between the IEPA and the DRSCW. Calibration of the probes for the other parameters listed was carried out according to the manufacturer's recommendations. 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't, ., _3,k: i+f'k .l.' rY- . �: i :2:z�1. ' i � d='✓'� »° cA°x� o�a,.ca �•''f� '�'c �'t- �, \' :'i..'G„ ,- '�:,t. 3 `�.,: -,- ;;�,,� :r�. „i': .'�i',;' - c%4`s4'+� 2`=l��v°';�.��,. `.�ts� s,.'ti` "�'rs:- '•�";,�;� C,��..�ss';� K�Sk,, a3,< ^a'i'^ �'�n�:, - `,s "�'�.< ^:,r'., j:, :Preserve.; -` {4 5 ,<.�bvti'":y � � i��R" a�'`£ ,y : i� n .".. - t`u{`y ``. �."�e.�.�< ?`Ft i %: ♦'r fib`. F {� YvZ 'in; ...e . �' _ ,.a__ T <' �.'.= ..4`�_`i�^,1 v ...�..,b,._,.v_s...atia.r.: -..:� ..2f,- a� -..�, c_,. . ^.:',�. ;.c �;:t•..,°. - r..g' -• �--- •— +�"'"'- -- ''- --y.- Te`y- Y .°-k --P-e, e-_'C.,�."Y..�.__ --r �-- _� .... _...r....: f_*'F - w' -w'- -" r- "-- "�;.- rr -r-'- `e'S s. _ ....._S'= •- .._�••rm-- i•__•7 e'rC. } �'Y a __{ �'G�a'}:`3:= ".'?•:i'5 � •_._•'a-�°— �. �� y'�,+.� t--• r'• -,S. rt t alt -e .. s�°ir� T t.•� '.•,>' 1 � t "'a^ Ate, BrocikAT = ..York,,Road °- - City -0:=of *Elmhurst' ..,x_ r__....a_�.....•.'�5.:.�_...... A summary of the minimum DO values for 2006 from the DRSCW probes are presented in Figure 2 -11. At Butterfield Road, DO values in June and July were recorded below the 5.0 mg/L minimum DO standard, although the majority of the days achieved the minimum standard. In Fullersburg Woods, minimum DO values below 5.0 mg/L were common in June 2006 while downstream of the dam the DO levels were consistently above the minimum standard and showed less variation. O O z g 6 s r 2 0 VD YI LO VL MONTH S" 0 * - 0 8 Z 6 -- - - ` 3 Q a---- - - - - -- Z 0 06 07 00 09 MONTH Figure 2 -11 DO values for 2006 Ub V/ UO Uif MONTH Figure 2-12 presents the DO results for the 2007 monitoring. The results are similar to the previous year. At Butterfield Road, DO levels in August dropped below 3.5 mg/L, the minimum DO standard for August, and in June levels below 5.0 mg/L were also reported. The minimum DO values in Fullersburg Woods in 2007 were below 5.0 mg/L for approximately 50% of the days in June, and also levels in July were below 5.0 mg/L. In August, the minimum was reported as less than 3.5 mg/L. DRSCW 2 -23 June 2009 8 SCYR 6 4 I ---- --- - -- 2 0 Figure 2 -11 DO values for 2006 Ub V/ UO Uif MONTH Figure 2-12 presents the DO results for the 2007 monitoring. The results are similar to the previous year. At Butterfield Road, DO levels in August dropped below 3.5 mg/L, the minimum DO standard for August, and in June levels below 5.0 mg/L were also reported. The minimum DO values in Fullersburg Woods in 2007 were below 5.0 mg/L for approximately 50% of the days in June, and also levels in July were below 5.0 mg/L. In August, the minimum was reported as less than 3.5 mg/L. DRSCW 2 -23 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions 15 co co E p 10 E i 0 SCFW 04 05 06 07 08 09 10 11 MONTH SCYR p 10[ E I 5 ------------------- 0 0 04 05 06 07 08 09 10 11 MONTH Figure 2 -12 DO values for 2007 To show the diurnal variation, a sign of plant /algae activity, the time plots for the same three stations in 2008 are depicted in Figures 2 -13, 2 -14, and 2-15. At Butterfield Road, a DO swing on the order of 3 mg/L was typical, with minimum DO levels reaching 2.5 mg/L. The low DO results recorded in September are associated with a large rain event that likely re- suspended in- stream sediments (although wash -off of CBOD materials and CSO operation cannot be ruled out). At Fullersburg, DO levels below 4 mg/L were reported in June, and in August approached 2.0 mg/L. DO swings at Fullersburg were typically 3 mg/L in May and June and less in July. After the heavy rains in early September, the DO swings were less than 0.5 mg/L reflecting the flushing of the algae out of the impoundment. At York Road, minimum DO levels were consistently above 5.0 mg/L, and the diurnal swing was consistently less than 2.0 mg/L. DO for SCBR MW-September 2006 14 12� Q 8 �� „��4n 4 P >c• 4 2ro� a•,^e ':"� �;'dh",�..', "a�`"r'm�.; 0� , _ ' Time Figure 2 -13 DO values for 2008 at Butterfield Rd DRSCW 2 -24 June 2009 15 SM C? i0 H D 04 Ora 06 07 08 09 10 11 MONTH SCFW 04 05 06 07 08 09 10 11 MONTH SCYR p 10[ E I 5 ------------------- 0 0 04 05 06 07 08 09 10 11 MONTH Figure 2 -12 DO values for 2007 To show the diurnal variation, a sign of plant /algae activity, the time plots for the same three stations in 2008 are depicted in Figures 2 -13, 2 -14, and 2-15. At Butterfield Road, a DO swing on the order of 3 mg/L was typical, with minimum DO levels reaching 2.5 mg/L. The low DO results recorded in September are associated with a large rain event that likely re- suspended in- stream sediments (although wash -off of CBOD materials and CSO operation cannot be ruled out). At Fullersburg, DO levels below 4 mg/L were reported in June, and in August approached 2.0 mg/L. DO swings at Fullersburg were typically 3 mg/L in May and June and less in July. After the heavy rains in early September, the DO swings were less than 0.5 mg/L reflecting the flushing of the algae out of the impoundment. At York Road, minimum DO levels were consistently above 5.0 mg/L, and the diurnal swing was consistently less than 2.0 mg/L. DO for SCBR MW-September 2006 14 12� Q 8 �� „��4n 4 P >c• 4 2ro� a•,^e ':"� �;'dh",�..', "a�`"r'm�.; 0� , _ ' Time Figure 2 -13 DO values for 2008 at Butterfield Rd DRSCW 2 -24 June 2009 D4 Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Figure 2 -14 DO values for 2008 at Fullersburg Woods Note, LDO stands for Luminescent DO, which refers to the method/equipment used for measurement. DO SCYR AA ay- October 2008 J IF r.6'�:� k" 0111 I 9NIN, 0 C2 H Ain Time Figure 2 -15 DO values for 2008 at York Rd, below Graue Mill Dam 2.8 biological and Phosphorus Quali ty In conjunction with the DO monitoring and addressing low flow low DO issues, the DRSCW was also collecting extensive fish and macro- invertebrate data on Salt Creek (Midwest Biodiversity Institute, 2008). Figure 2 -16 summarizes the Index of Biotic Integrity (I8I) for the fish collected. Moving downstream from the mouth, the biodiversity scores are higher (bett er) above the Fullersburg Impoundment, where a sharp drop in fish bio- diversity occurs. Downstream of the Graue Mill Dam, the highest (best) biodiversity scores on Salt Creek were recorded. Nineteen fish species were found below the Graue Mill Dam, while only 13 species were collected above this dam. The spike in IBI immediately below the dam is probably due to crowding as fish migrating upstream encounter the barrier (for example white suckers were found downstream of Graue Mill Dam). Wastewater treatment plant and Combined Sewer Overflows (CSOs) locations are also depicted in Figure 2 -16. There is no consistent change in IBI scores above or below treatment plants. Biodiversity scores are the poorest near Butterfield Road, where as described previously the creek as been over- widened resulting in very low velocities, sediment deposition, and the establishment of excessive rooted vegetation. This is also downstream of a number of CSO points. DRSCW 2 -25 June 2009 DO for SCFW April- October 2008 .. d'�S�la°'"ay.� (,�R��'��. 1 &\` iY� �`• °M1i �`�'�}�,� 'k.� ,':T$r ,i: 12 `�xN `,;i �'' . �, �('� f : •,�. ;,� 4 a�_/vF '�, 9a i,t`e_� H�� e i`,��,�+n w�xN 2 Ao i y', '• "4b •'f;,A:; °� °��c�� "x K.�s, �e 10 L�,i.:° �h:'�E �, \'� `.�`.`'�N�� t v Y �• >�ov -L. ° .. >. x. v`"ro- "i>,Fe r`�. =, 0.n,, >� �£` �.,m c� tJa i � Yd�.�'�'c t LDD O 6 O 4 2 01 mm O pWp m Gp a 21 O O A O O (��I O O O O a O O O Time Figure 2 -14 DO values for 2008 at Fullersburg Woods Note, LDO stands for Luminescent DO, which refers to the method/equipment used for measurement. DO SCYR AA ay- October 2008 J IF r.6'�:� k" 0111 I 9NIN, 0 C2 H Ain Time Figure 2 -15 DO values for 2008 at York Rd, below Graue Mill Dam 2.8 biological and Phosphorus Quali ty In conjunction with the DO monitoring and addressing low flow low DO issues, the DRSCW was also collecting extensive fish and macro- invertebrate data on Salt Creek (Midwest Biodiversity Institute, 2008). Figure 2 -16 summarizes the Index of Biotic Integrity (I8I) for the fish collected. Moving downstream from the mouth, the biodiversity scores are higher (bett er) above the Fullersburg Impoundment, where a sharp drop in fish bio- diversity occurs. Downstream of the Graue Mill Dam, the highest (best) biodiversity scores on Salt Creek were recorded. Nineteen fish species were found below the Graue Mill Dam, while only 13 species were collected above this dam. The spike in IBI immediately below the dam is probably due to crowding as fish migrating upstream encounter the barrier (for example white suckers were found downstream of Graue Mill Dam). Wastewater treatment plant and Combined Sewer Overflows (CSOs) locations are also depicted in Figure 2 -16. There is no consistent change in IBI scores above or below treatment plants. Biodiversity scores are the poorest near Butterfield Road, where as described previously the creek as been over- widened resulting in very low velocities, sediment deposition, and the establishment of excessive rooted vegetation. This is also downstream of a number of CSO points. DRSCW 2 -25 June 2009 >'° '¢, .. d'�S�la°'"ay.� (,�R��'��. 1 &\` iY� �`• °M1i �`�'�}�,� 'k.� ,':T$r ,i: `�xN `,;i �'' . �, �('� f : •,�. ;,� 4 a�_/vF '�, 9a i,t`e_� H�� e i`,��,�+n w�xN 2 Ao i y', '• "4b •'f;,A:; °� °��c�� "x K.�s, �e :� f �'�itin�'�c n�Y+,p oa L�,i.:° �h:'�E �, \'� `.�`.`'�N�� t v Y �• >�ov -L. ° .. >. x. v`"ro- "i>,Fe r`�. =, 0.n,, >� �£` �.,m c� tJa i � Yd�.�'�'c Figure 2 -14 DO values for 2008 at Fullersburg Woods Note, LDO stands for Luminescent DO, which refers to the method/equipment used for measurement. DO SCYR AA ay- October 2008 J IF r.6'�:� k" 0111 I 9NIN, 0 C2 H Ain Time Figure 2 -15 DO values for 2008 at York Rd, below Graue Mill Dam 2.8 biological and Phosphorus Quali ty In conjunction with the DO monitoring and addressing low flow low DO issues, the DRSCW was also collecting extensive fish and macro- invertebrate data on Salt Creek (Midwest Biodiversity Institute, 2008). Figure 2 -16 summarizes the Index of Biotic Integrity (I8I) for the fish collected. Moving downstream from the mouth, the biodiversity scores are higher (bett er) above the Fullersburg Impoundment, where a sharp drop in fish bio- diversity occurs. Downstream of the Graue Mill Dam, the highest (best) biodiversity scores on Salt Creek were recorded. Nineteen fish species were found below the Graue Mill Dam, while only 13 species were collected above this dam. The spike in IBI immediately below the dam is probably due to crowding as fish migrating upstream encounter the barrier (for example white suckers were found downstream of Graue Mill Dam). Wastewater treatment plant and Combined Sewer Overflows (CSOs) locations are also depicted in Figure 2 -16. There is no consistent change in IBI scores above or below treatment plants. Biodiversity scores are the poorest near Butterfield Road, where as described previously the creek as been over- widened resulting in very low velocities, sediment deposition, and the establishment of excessive rooted vegetation. This is also downstream of a number of CSO points. DRSCW 2 -25 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions Fish Biodiversity Scores Salt Creek 60 Wood Date North On ,;�g,F Wood Dale South - Egan Adason Itasm Lamm Etmhust 40 I — -- __- -- - - -- -- - -- I -- - -------------------------- - - - - -- Good m L=Wd 20 - Cso A Mel" Huts Sproq) Aft" &Wch Book ♦ AMA ♦ A Creek 0 40 30 20 10 0 River Mile Figure 2 -16 Fish Biodiversity Figure 2 -17 presents the macro - invertebrate quality index, as well as calculated QHEI (Qualitative Habitat Evaluation Index) scores. A similar phenomenon occurs with the benthic organisms at the Graue Mill Dam; however, further upstream the benthic index improves to levels observed downstream of the Graue Mill Dam. 1 rtebrate and Habitat Scores for Salt Creek MIBI 0 QHEI 60 Habitat 0 X 40 N C 20 Bugs 01 40 30 20 10 0 River Mile Figure 2 -17 Macro- Invertebrate Quality The Illinois Nutrient Standard Workgroup has conducted extensive research over the past five years on the correlation between nutrients, algae, and minimum DO levels. Several findings of this group's research are that on mid -sized streams in Illinois; nutrients are never limiting sestonic, periphyton or macro -algae growth, but rather light, substrate, and stream velocities are important factors (David, M., et al., 2007). For phosphorus to be controlling, the Illinois research suggests that the total phosphorus needs to be less than 0.07 mg/L (Ibid). Figure 2 -18 presents the total phosphorus measured levels along Salt Creek. In the headwaters, the levels are near the 0.07 mg/L level, and quickly increase above 0.10 mg/L by RM 32 (river kilometer 51.5). Above the first wastewater treatment plant, the total phosphorus is typically above 0.2 w DRSCW 2 -26 June 2009 DD Improvement Feasibility Study Salt Creek 2.0 Existing Conditions mg/L. The total phosphorus level in the lower 25 miles (40 km) remains steady at an average of approximately 0.7 mg/L. 10.00 1.00 0 2 0 o. 0 ,Q 0.10 0 F- 001 45 40 30 20 10 0 River Mile 1 MWRDGC Egan WRP 4 Wood Dale South STP 7 Salt Creek Sanitary District 2 Itasca STP 5 Addison North STP 8 Elmhurst WWTP 3 Wood Dale North STP 6 Addison South -A.J. Larocca STP 9 Addison Creek Figure 2 -18 Phosphorus Levels in Salt Creek 2.9 Summary Salt Creek is a highly disturbed urban stream, with low channel gradients and extensive channelization. The wastewater treatment plants contribute a significant percentage of the total phosphorus on Salt Creek; however, above the first treatment plant, the phosphorus concentrations are already above the level that has to be attained for phosphorus to become a limiting factor for plant and algal growth. The flow contributed by the wastewater treatment plants during low flow is beneficial from reducing temperatures and increasing stream velocities, both key factors in controlling plant and algal growth when phosphorus levels are above 0.07 mg/L. DRSCW 2 -27 June 2009 DO Improvement Feasibility Study Salt Creek 2.0 Existing Conditions The continuous DO monitoring has identified the DO above the Graue Mill Dam as the lowest on Salt Creek. SOD results in the Fullersburg Woods Impoundment (above the Graue Mill Dam) are elevated in the sediment that has accumulated behind the dam, a factor accentuated by the residence time and geometry of the impoundment. The biological studies have also shown that the Graue Mill Dam is acting as a physical barrier to fish migration, and the fish biodiversity above the dam is the significantly lower than that below the dam. From the results presented in this section, a dissolved oxygen model was developed, which is presented in the next section. The model was used to prioritize projects and develop alternatives From this model, alternatives for improving DO levels within Salt Creek are developed in following sections. DRSCW 2 -28 June 2009 DO Improvement Feasibility Study Salt Creek 3 WATER QUALITY MODELING The Illinois Water Quality Report 2006 identifies Salt Creek as impaired for a number of water- borne pollutants including low dissolved oxygen. Modeling analyses of Salt Creek were conducted in order to allocate allowable waste loads for BOD5 and ammonia using a water quality model called QUAL2E. The TMDL water quality model of Salt Creek was calibrated using field sampling data collected in June 1995. Since the TMDL reports in October 2004, the DuPage River /Salt Creek Work Group has improved the database from which a calibrated model could be developed. The purpose of water quality modeling is to identify locations of low DO and then quantitatively evaluate the effects of alternatives used to improve DO. The modeling tool used in the TMDL study (QUAL 2E) has been updated with a more user - friendly interface, more flexible inputs and convenient post- processing tools. The updated version of QUAL2E is called QUAL2K and was developed for the USEPA by Steve Chapra, et. al at Tufts University ( Chapra et al 2005). Model theory, equations and parameters are described completely in the QUAL2K Users Manual. Model conversion to QUAL2K from QUAL2E and validation of the new modeling tool (QUAL2K) are described herein. 3.1 Conversion of QUAL2E to QUAL2K Model The fundamental utility of QUAL2E and QUAL2K is essentially the same; they are one- dimensional, steady -state models to predict DO and associated water quality constituents in rivers and streams. However, QUAL2K has more refined features such as the capability of diurnally varying headwater / meteorological input data and a full sediment diagenesis model to compute sediment oxygen demand (SOD) and nutrient fluxes from the bottom sediment to the water column. In addition, the QUAL2K model offers more options for decay functions of water quality constituents, reaeration rate equations, heat exchange and photo - synthetically available solar- radiation calculations. As the fundamental theoretical underpinnings of both models are similar, the objective of this subtask was to use the input data previously used in QUAL2E and produce QUAL2K outputs that are similar to the results found in the TMDL reports. Since QUAL2E input data files were not available, the listings of input data in the appendices of the TMDL reports were used to prepare the input to QUAL2K. The QUAL2E model set -up was closely followed to reproduce those results by applying QUAL2K instead of QUAL2E. The more refined features in the QUAL2K, described above, were not implemented in order to adhere, at least initially, to the QUAL2E modeling process. Model boundaries, running from the spillway at Busse Woods Dam to the confluence of Salt Creek and the Des Plaines River remained the same. Subsequently, we independently evaluated the selection of model formulations and functions and parameter evaluations for Salt Creek as described in section 3.2. 3.2 Validation of QUAL2K Model After converting the QUAL2E model to QUAL2K, recent DO measurement data were needed to validate the QUAL2K model. Several potential sources of data include the DuPage County field DRSCW April 2009 DO Improvement Feasibility Study Salt Creek samples from the summer of 2005, the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), and newly installed DRSCW DO probes along Salt Creek. The DO in Salt Creek was measured by DuPage County during several days starting on July 8, 2005 and ending on August 10, 2005. The field data consist of date, time, station number, cross - section position (left, middle, right) sample depth and DO. It is important to note that the measurements were performed during daylight only so that the cyclically low DO due to respiration of phytoplankton during the night time was not captured. The MWRDGC has continuous measurements of DO and temperature at three stations along Salt Creek: JFK Boulevard (RM 28.7, River km 46.2), Thorndale Avenue (RM 26.9, River km 43.3) and Wolf Road (RM 8. 1, River km 13.0). The first station is situated near the upstream boundary of the model and these data were used to specify headwater conditions. The second station is 3.1 miles (5 km) from the model upstream boundary such that the elapsed travel time to this point is limited and therefore only minimal change in simulated water quality would be expected. The third MWRDGC station is located more than 3.lmiles (5 km) downstream of the Graue Mill Dam, and is not within the extent where alternative aeration projects are being considered. The DO and temperature measurements at Wolf Road were reviewed to see the diurnal variation. However, these data are not graphically compared to the model results because the selection of the time when the creek was at steady -state conditions could not be made without the stream flow data. Reach lengths were modified in QUAL2K based on up to date GIS data developed as part of this project as opposed to USGS RM information used in QUAL2E. River mile /km differences for Salt Creek were as high as 2.4 miles /3.8 km in the upstream reaches (near RM 25,River km 40.2) and gradually decreased with distance downstream between the GIS and USGS data. The DO data were plotted against river distance to show the range in DO and provide an approximate basis for comparing QUAL2K results. As QUAL2K is a steady -state model, it assumes that stream conditions, such as flow, point source discharge and loadings, are constant in time. Sampling to collect data for comparison to a steady -state model is normally performed during periods when flow and other conditions are relatively constant. However, the initial DO data may not reflect steady -state conditions because of the variability in flow, meteorology, point source loadings and headwater conditions during the 32 day sampling period. 3.2.1 Model Inputs This section describes the model inputs developed to simulate the period of DO data collection, as well as changes to the hydraulic characteristics (i.e., stream slope, depth and width data) necessary to reflect findings obtained during the field data collections (see Section 2.0, Existing Conditions for more details) and additional data collected. Reaction rate coefficients that depend on stream depth and velocity, such as the reaeration rate coefficient and the BOD oxidation coefficient, were also changed to reflect the changes in the hydraulic data. Other model parameter values from QUAL2E were also changed in QUAL2K in an attempt to improve its ability to simulate conditions in Salt Creek as explained below. • Headwaters and Tributaries: Headwater flows were changed using historical USGS flow data for 20 years or more. Monthly average flows for July and August for the period of record were averaged. Flows from point sources were accounted for in calculating flows with distance upstream of the gaging stations. Tributary flow was DRSCW April 2009 DO Improvement Feasibility Study Salt Creek also estimated based on the ratio of flow to drainage area at the gaging station and the estimated drainage area of the tributary. Water quality measurements at the headwaters during July - August, 2005 would have been* ideal, but they were not available at this time. The hourly DO at the headwater of Salt Creek was based on the JFK Blvd. station continuous DO measurements from MWRDGC. This station is located near the headwater of the main reach of the Salt Creek, and therefore is representative of the boundary conditions of the model. The same diurnal variations of DO and water temperature were also implemented for the tributaries. The DO, CBOD5, and ammonia concentrations of the tributaries were assumed to be the same as the QUAL2E model. • River Distances: As mentioned earlier, stream reach lengths were modified in QUAL2K based on GIS data developed for this project whereas USGS information was previously used in the QUAL2E model. • Model geometry: Main channel slopes were revised using the Digital Elevation Model (DEM) developed by USGS for Salt Creek. The DEM is publicly available in a GIS format and elevation information for end points of each reach segment was extracted from the overlay of the DEM and reach end points set up in QAUL2K. In addition, impoundment areas, where there are occurrences of hydraulic backup and sedimentation due to the presence of dams, were delineated as a refinement in QUAL2K. This was done by subdividing the appropriate QUAL2E model reach into two reaches for QUAL2K, a free - flowing reach and an impounded reach. Water depth information was taken from the Existing Conditions Report (see Section 2.0). These changes of channel slope, depth and velocity in impounded areas would potentially change reaeration rates and BOD deoxygenation rates as explained under "decay rates" below. • Meteorological Data: Air, dew point temperatures were changed to represent more reasonable local effect of weather for a period with which model validation was compared. Other meteorological inputs such as wind speed, cloud cover and shades were set to 0 m/s, 30% and 0 %, respectively. As the primary intent of the model is to simulate hot, low flow conditions, precipitation data are not included as input. • Decay Rates: As stated, changes to the stream geometry indicated that reaction rate coefficients would also change. CBOD, nitrification and settling rates of various water quality constituents were changed using stream characteristics and a more reasonable range based on Chapra 1997, Thomann and Mueller 1987 and EPA 1985. Velocity and depth are generally calculated by QUAL2K except for impounded reaches, where these data are taken from the Existing Conditions section and directly input to the model. Appendix 3 includes the inputs for the decay rates and reaeration rates in Salt Creek. • Background Light Extinction: In an effort to account for the fact that the model lacks absorption and back scatter of light by particulates (total suspended solids (TSS) was not simulated in the model), a higher background light extinction rate was used compared to QUAL2E inputs. Appendix 73 includes the light and heat inputs. DRSCW April 2009 DO Improvement Feasibility Study Salt Creek o Point Sources: There are seven municipal wastewater treatment plants that discharge into Salt Creek. These are depicted on the graphs developed by letter code, as I ummarized below: Point Source Label Distance from Mouth, km Egan a 47.6 Wood Dale N b 40.7 Wood Dale S c 38.1 Addison N d 36.5 Addison S e 33.9 Salt Creek SD f 28.6 Elmhurst g 28.2 Monthly DMR data for July and August 2003 were utilized as typical low flow, summer effluent quality. The monthly average values were used to set discharge flows, CBOD5 and ammonia concentrations. Other effluent data, such as organic nitrogen, nitrate, phosphorus and DO concentrations, were not available in the DMR data; therefore, the previous QUAL2E inputs were used. • Temperature: Based on historical temperature data, the stream temperature reaches temperatures approximately 3 °C warmer than was observed in June /July 2005. Figure 34 depicts the stream temperature that would be used for the baseline conditions, reflecting the worst case conditions. Salt Creek Mainstem Monthly Average of June 2005 DMR Condition with 3 ° C Increased Plant Discharge and Air Temperature a b c d e f9 30 25 620 m i ice+ C1 a E 1s m 10 5 0 L 50 -- _ - - - --- -------- - - - - -- ---------------------- - - - - -- --------------------- 45 40 35 30 25 20 15 10 5 Distance from downstream (km) —Temp(C) Average — — Temp(C) Minimum Temp(C) Maximum 0 Point Source ■ July Daily Average Data August Daily Average Data Figure 3 -1. Monthly Average Temperature June 2005 0 DRSCW April 2009 DO Improvement Feasibility Study Salt Creek 2.0 1.8 1.6 1A 1.2 E i 1.0 0.8 0.6 OA 0.2 00 • Flow: Figure 3 -2 depicts the base flow predicted in Salt Creek based on the actual discharges from the wastewater treatment plants in June 2005 and the base flow. The resulting travel times under low flow conditions is presented in Figure 3 -3. The overall travel time from the most upstream wastewater treatment plant (Egan) to the mouth is on the order of 5 days under low flow conditions. Saft Creek Mainstem Monthly Average of June 2005 DMR Condition with 3 ° C Increased Plant Discharge and Air Temperature a b c d a f9 ------------------------------------------------------------------------------------------ --------------------------------------- --------------------------------------------------- --------------------------------------- -------------------------------------------------- ------------------------ ----------------------------------------------------------------- --------------- -------------------------------------------------------------------------- ---- ------------------------------------------------------------------------------------ ---- ------------------------------------------------------------------------------ - - - - -- - 50 45 40 35 30 25 20 15 10 5 -Q, m3/s A Point Source Figure 3 -2. Base Flow for Salt Creek 0 DRSCW April 2009 DO Improvement Feasibility Study Salt Creek 6.0 5.0 a 4.0 m E m 3.0 2.0 1.0 00 Saft Creek Mainstem Monthly Average of June 2005 DMR Condition with 3 ° C Increased Plant Discharge and Air Temperature a b c d a f9 ------------------------------------------------------------------------- - - - - -- --- - - - - -- ----------------------------- -------------------------------------------------- -------------------------------------- -------------------------------------------------------- ----------------- ------------------------------------------------------------------ - - - - -- . s0 45 40 35 30 25 20 15 10 5 0 �trav time, d e Point Source Figure 3 -3. Travel Times under Low Flow Conditions for Salt Creek Sediment Oxygen Demand: The SOD rates in the TMDL QUALM model input listings estimated at 0.2 to 1.5 g/m 2 /d for Salt Creek were lower than expected for the existing conditions. SOD measurements were conducted on Salt Creek in 2006 and 2007 to improve input into the QUALM model. The SOD measured at ambient temperature in Salt Creek ranged from a minimum of 0.28 g/m2 /day to a maximum of 3.60 g/m2 /day. The highest SOD was observed in the impoundment upstream of Graue Mill Dam, and at a single site below the Graue Mill Dam, which does not appear representative of this stretch. Figure 3 -4 presents comparisons of the SOD results during the 2006 and 2007 surveys, adjusted to a water temperature of 20 °C. The 2007 SOD rates are similar to the 2006 SOD rates in the impoundments of the Old Oak Brook and Graue Mill Dams. Using the base temperature (see above), the measured SOD rates were adjusted. Figure 3 -5 presents the SOD rates with the 3 °C increase in June temperatures for each segment of the creek. DRSCW April 2009 DO Improvement Feasibility Study Salt Creek 8.0 7.0 6.0 a 5.0 UO 4.0 3.0 2.0 1.0 00 6.0 5.0 4.0 c N E rn °p 3.0 rn 2.0 1.0 0.0 Comparison of 20 °C- Temperature Corrected SOD In Salt Creek Oak Meadam Gag Course dam Old Oak Break dam Draw Mg (Fullersbtrg) Dcm ------------- ----- - - - - -- ------------------------------ - - - --- - - - -- ------------------------------------- ■ ■ ■ ■ ■ ■ ------------- ---- - - - - -- ------------------------------- As - - - -- ------------------------------------- ■ 30 25 20 15 10 5 0 ■ 2006 SOD Survey ■ 2007 SOD Survey Figure 3 -4. Comparison Temperature Corrected SOD in Salt Creek Salt Creek Mainstem Monthly Average of June 2005 DMR Condition with 3 ° C Increased Plant Discharge and Air Temperature a b c d e f9 ------------------------------------------------------------------------------------------- ---------------'-------------------------------------------------------------------------- - - - - - - - - - - - - - - - - - - - - - i - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ------------------------------ -- - - - - - - - - - - - - - --- - - - -�f -- - - - - - - - - - -� —a -----------' i- �;----------------------- - - - - -- � �� ■7 (,fir -- - - -- - -� ------------------------------- ----------------------- •----- - - - - -- - - - - -- - - - - -i- r---------------- - - -- -- -------------I-----------r.-_1----------------------------------- L L- - -- ------------------------------------------------- ----------------- - - - - -� ( - - -- — - - 50 45 40 35 30 25 20 15 10 5 Distance from downstream (km) -SOD gO2lm "21d ■ SOD -data - Prescribed SOD gO2/m2/d ® Point Source Figure 3 -5. SOD rates with the 3 °C increase in June temperatures DRSCW April 2009 0 DO Improvement Feasibility Study Salt Creel 3.2.2 Calibration and Verification of the Model Under low stream flow conditions, the contribution from the point source discharges to Salt Creek collectively account for 46% of the total flow at the model's downstream boundary. To calibrate the model data from August 2, 2007 were utilized. The model inputs are included in Appendix B, and the predicted DO versus measured DO at specific locations is depicted in Figure 3 -6. Stream temperatures ranged from 23 to 3 I on this date, and the stream flow was essentially at low flow conditions. The model, as presented in Figure 3 -6, predicted higher minimum DO values above Oak Meadows Dam and below the Crraue Mill Dam, generally by less than 1 mg/L. However, overall, the model reasonably predicts the diurnal change in DO. To verify the model will accurately predict DO changes under varying conditions, the model was run for the conditions on June 20, 2006 and for conditions on August 15, 2006. Input data are presented in Appendix B, and the model prediction is presented in Figure 3 -7, along with actual DO measurements. A larger diurnal swing in DO was present above the Old Oak Brook Dam than predicted. This is attributed to an increase in algal and aquatic plant population. Measured DO minimum levels were also lower than the model predicted; however, the results were within 0.5 mg/L. Model conditions overall showed excellent agreement with observed conditions in the calibration model and both validation models. 12 10 8 E g s 4 2 Salt Creek (81212007) Mainstem Comparisons of Observed and Predicted Dissolved Oxygen: 2007 Calibration Run Oak Meadows Golf Course dam Old Oak Brook dam Fullersbura Woods Dam (Graue Mill) a b ( Lid a f 9 -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - j - � - - - - - - - - - - - - - - - - - - - - - - - - - ` -� -- _ - - - - - - - - - - - - - - ^ -� -- IIIIIIIIIIIIIIIIIIIIIilljl o - -- - -- - - - - -- - - - - - -- ---- ��-- - - - - --- - - - -- - - - -�� ----------------------------- 0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ --------------- 111 ___ ____� 0 �_ s0 45 40 35 30 25 20 15 10 5 0 Distance from downstream (km) —DO(mgO21L) ■ DO (mgO21L) data ° DO(mgO2 1L) Min — DO(mgO2 1L) Max o Minimum DO -data o Maximum DO -data - - DO sat n Point Source Figure 3 -6. Predicted vs. Measured Dissolved Oxygen for August 2007 for Salt Creek DRSCW April 2009 DO Improvement Feasibility Study Salt Creek 12 a 10 8 J Ss 4 2 Salt Creek (612012006) Mainstem Comparisons of Observed and Predicted Dissolved Oxygen: 2006 Validation Run (6/19/06 to 6121/06) Oak Meadows Golf Course dam e f9 Old Oak Brook dam Fullersburg Woods Dam (Graue Mil) - ----- - - - - -� - --- - - - - - - - - - - - - � - - - - - - - - - - - - - - - -- - -' - - - - - - - - - - - -- -- �- -- - - - - -- AIR r- r.-i. - -�- � � r tit 0 - 0 ------- - - - -- ------ ��---- - - - - -- _ 0i 50 45 40 -DO(mgO21L) 0 Minimum DO -data 35 30 25 20 15 Distance from downstream (km) ■ DO (mgO2/L) data DO(mgO21L) Min 0 Maximum DO -data DO sat 10 5 0 DO(mgO21L) Max A Point Source Figure 3 -7. Predicted vs. Measured Dissolved Oxygen for July 2006 for Salt Creek 3.2.3 - Sensitivity Analysis Sensitivity runs were completed for changes in both SOD and re- aeration constants. These results are presented in Appendix B. Both of these variables have a significant impact on the predicted DO values; however, such changes do not improve the overall predictions compared to the actual results. 3.2.4 Baseline Model The value of a model is to predict worst case conditions and the impacts of improvement alternatives on those conditions. In modeling the worst case scenario, temperature is a prime factor, as the temperature increases, reaeration decreases and respiration increases (both in the water column and in the sediment). Recall, from a review of historical temperature data, the stream can reach temperatures approximately 3°C above the levels recorded in June 2005. This temperature and low flow, with the average summer CBOD and ammonia discharged from the seven wastewater treatment plants was used as the baseline worst case scenario. Figure 3 -8 presents this baseline model. From this model, alternatives for improving DO levels can be evaluated, and this is done in Section 6. The Baseline Model predicts minimum DO levels just above the Oak Meadows Dam reaching 3.5 mglL. At the Old Oak Brook Dam, the minimum DO DRSCW April 2009 DO Improvement Feasibility Study Salt Creek predicted is at 4.1 mg/L, and just above the Graue Mill Dam, minimum DO levels are predicted to reach 1.2 mg/L. The model, consistent with the monitoring results predicts under these extreme conditions, the pool areas created by the dams are the areas with the lowest DO levels. As the Old Oak Brook Dam pool is not as significant as the other two dams, its impact on DO is less pronounced. 11 10 9 s 7 E s °c s 4 3 2 1 Salt Creek Mainstem Monthly Average of June 2005 DMR Condition with 3 ° C Increased Plant Discharge and Air Temperature Oak Meadows Goff Course dam Old Oak Brook dam Fullersburg Woods Dam (Graue Mill) a b C V14 e f9 - - -- ------------------------------- --- - - - - -- ---------- - - - - -- --------------------------------- ---- -+r -Mb- � -. • �- • • .' . • • . � • • `"�• • • • � . • lei • • . . � • � • • • - - -�� ------ - - - - -- ----- - - - - -- --- - - --�- ----------------------------------- -�- - - -i -- - - - - - -- - - - - -- - - -� - - - - -- - - - -- ------ ��, - -,I �� - - - - -- --------- - - - - - -- - -- - - -- --�� - - - - - -- )-------------- - - - - -- � -- - �� - - - -- - ��- 1 ,�- - - -- ------ - - - - -- - - - -- --- ----------- - - - - ------------------------------- ------------------ - - - - -- — - -- �1'(------------- -- - - -- - � -- _J ---- p------------- - - - - -- ------------------------ - - - - -- - - - -' ------------------------------- C --- °------------- - - - - -- ------------------------ - - - - -- - - -I ------------------------------- 0 �- 50 45 40 35 30 25 20 15 10 5 0 D"tstance from downstream (km) �DO(mgO21L) ° DO(mgO21L) Min n DO(mgO2/L) Max DO sat o Point Source Figure 3 -8. Baseline Dissolved Oxygen for Salt Creek DRSCW April 2009 DO Improvement Feasibility Study Salt Creek 4.0 Screening for Dams 4 SCREENING FOR DAMS Small, low -head dams impose a number of negative impacts on rivers through both their nature and their number. Dams inhibit the natural linear flow of energy in the stream system, be it in the form of flowing water, sediment transport, fish migration, macro invertabrate drift, or downstream nutrient spiraling. Specific to the impact on dissolved oxygen, dams create impoundments that concentrate sediment and organic material upstream which actively respires, removing dissolved oxygen from the water. In addition, dams slow the velocity of the water, allowing additional time for sediment decomposition to remove oxygen from the water column and for solar energy to increase water temperature (water temperature is inversely correlated to waters capacity to hold dissolved oxygen). These effects are further exacerbated as dams increase the width of the stream, increasing the water column/sediment interface and limiting the extent that riparian shade can counter the effect of solar heating. As water temperatures increase, the re- aeration rate from the atmosphere decreases because the DO saturation value decreases with increasing temperatures. Complete removal or retrofitting of dams is an increasingly utilized tool to eliminate the disruptive influence that dams create within the fluvial system. The impacts of dams on sediment continuity, flood conveyance, and aquatic flora and fauna have been well documented in the literature. However, there is little guidance that exists for handling a dam removal or retrofit. Questions about the fate of impoundment sediment, mechanisms for dewatering, and short versus long term impacts to the health of the stream dominate any dam removal or modification project, and must be addressed prior to the actual project. The three options being investigated in this study are: complete removal; partial breach, and partial removal with bridging. These options are being driven by the primary design objective of improving the DO content of the stream. A secondary design objective is to re- establish biological connectivity, mainly in the form of faunal passage. 4.1 Complete Removal Complete dam removal involves the removal of the entire dam structure. The most common case for removal is to eliminate the legal definition of a dam at a particular site, thereby removing liability and responsibility from the owner. Usually dams have exceeded their design life, and the cost of rehabilitation is greater than the cost of removal. Ecological benefits can be significant. Complete removal can occur in a number of ways based on site conditions and budget. Dams with a substantial amount of sediment behind the structure are typically drawn down in stages to minimize the downstream transport of sediment. Sediment in the dewatered impoundment can be excavated and /or stabilized in place, depending on the type and quality of material (i.e., silt versus sand and contaminated versus non - contaminated). Depending on the size of the impoundment, varying levels of restoration of the new channel are required. In large impoundments, the effort for restoration is great, while in narrow impoundments, the restoration effort may be less extensive. There is a broad range of effort that can be dedicated to restoration of the site based on funding, aesthetics, resource use, aquatic and terrestrial wildlife needs, hydrology, and sediment transport. DRSCW - 1 - April 2009 DO Improvement Feasibility Study Salt Creek 4.0 Screening for Dams A passive approach (minimal effort) to channel rehabilitation might include the excavation of a fairly straight, perhaps oversized channel through the impoundment. This would allow the stream to do most of the work of recovery, creating its own path and allowing flood and groundwater hydrology to dictate the riparian vegetation regime over a prolonged timescale. Time scales for the completion of this restoration can range from decades to centuries depending on site conditions. Alternatively, active channel restoration, requiring the largest effort, would involve the complete construction of a functioning floodplain and sinuous channel similar to what existed prior to dam construction. The geometry of this channel would emulate the historical channel but would be designed to function appropriately within the constraints of modern hydrology and sediment loading. This active restoration option could be constructed within a few months but for a greater cost. The costs and time scales for these approaches are drastically different to achieve the same ultimate outcome, the re- establishment of an intact fluvial system. 4.2 Partial Breach or Notching Breaching includes everything from a simple v -notch weir to removal of a section of a dam (partial breach). Depending upon the design, sediment transport and fish passage can be achieved.. However, if the velocity through the breach is too great, fish passage may not occur, and safety issues to paddlers could also result. 4.3 Bridging The third option is bridging. The basic concept is to build a ramp of large rock leading up to the downstream face of the dam. The ramp effectively "bridges" the dam by providing upstream - downstream fish passage and possibly canoe passage. Common variations to this include partially removing or lowering the dam crest in order to decrease the vertical elevation that must be made up downstream and to reduce the impoundment on the upstream side of the dam. In addition, notching the dam crest (alternative 2) to concentrate flow in the center of the channel is also common. Bridging provides fish passage and aeration as well as some interstitial habitat for macroinvertabrates. It also preserves some elevated water surface elevations upstream. Bridging, with a resulting lowering of the poll elevation, will reduce retention time, summer temperatures, and sediment deposition. Bridging does not remove the legal designation of a dam at the site. The State of Illinois' definition of a dam is "any structure built to impound or divert water." Thus the responsibility for maintaining and monitoring the structure will remain with the dam owner. There is a possibility for the hazard classification of the structure to be downgraded if partial removal diminishes the hydraulic impact of the structure. 4.3 Issues Common to All Dams There are several issues that need to be addressed for projects with modifications to existing dams. Permitting by federal, state, and local agencies, characterization and disposal of sediments removed from dam impoundments, and impacts of dam removal on flooding must be considered. DRSCW - 2 - April 2009 DO Improvement Feasibility Study Salt Creek 4.0 Screening for Dams 4.3.1 Permitting In Illinois, the resource agencies generally recognize the ecological benefits of dam removal /bridging projects. However, the historical characteristics of a dam must be weighed against any modifications to a structure. Storm water and wetland impacts are two central issues around any project that will modify /remove a dam. There are three levels of permitting that will be required for each project, with variations on each depending on the design method chosen. The Joint Permit Application Packet is designed to simplify the approval process for the applicant seeking project authorizations from the U.S. Army Corps of Engineers, the Illinois Department of Natural Resources Office of Water Resources, and the Illinois Environmental Protection Agency. Federal Level — At the federal level, the Army Corps of Engineers has jurisdiction over any design that will impact wetlands or waterways. Because DuPage County's regulations are more stringent than the Federal Laws, a memorandum of understanding has been in place that allows much of the permit review for the Federal 401/404 permit to be accomplished by the County. An Environmental Assessment will be required for any dam modification/removal project if federal funds are utilized. A Regional 404 permit would be applied for dam removal or modification. State Level — Permitting from the State of Illinois involves primarily the Illinois Department of Natural Resources (IDNR) and the Illinois Historic Preservation Agency. Within the Joint Permit Application process, there are several layers of review that require the approval of various agencies. The IDNR Office of Water Resources has established requirements for applications for permits to remove dams, detailed in Section 3702 of the State Administrative Code. The Office of Water Resources handles aspects mainly related to the construction (removal) process, such as the plan for dewatering and upstream restoration and the impacts to the flood profile. The IDNR Office of Realty and Environmental Planning will perform a review of the project to ensure no impacts to threatened or endangered species. A review will be done by the Illinois Historic Preservation Agency to ensure no impacts to state historic or archaeological resources. This Agency has consistently determined that dams have historical significance, and this would certainly be true for the Graue Mill Dam and, therefore, any modifications will be closely reviewed by this Agency, and the conflict between the ecological benefits and changes to a historical structure will have to be weighed. If federal funds are used to remove Graue Mill Dam, a Section 106 analysis may be needed. Additional regulations that may apply depending on the project include Part 3708 — Floodway Construction in Northeastern Illinois. The IEPA provides water quality certifications (401) for Individual 404 permits; however, this project analysis is not necessary for Regional Permits. Previous dam removal projects have only required a Regional Permit. County Level - DuPage County permitting requirements are more stringent than most State or Federal requirements. As a result, once the county requirements are met for various items held in common among both state and federal regulations, the federal and state requirements are also met by default. It is important to note that this is only for certain items, such as wetland impacts, that are common among the three levels of permitting. Other items, such as dam safety and the regulations associated therein, are not common among the various permitting agencies and so the responsibility remains with the issuing agency, in this case, IDNR. DRSCW -3 - April 2009 DO Improvement Feasibility Study Salt Creek 4.0 Screening for Dams The county has a single permit application that covers all work in waterways that will be proposed on this project. The storm water permit includes provisions for hydraulic /floodplain impacts, wetland impacts, and property impacts. Hydraulic /floodplain impacts are the most important category to identify prior to taking any project beyond conceptual design. It is premature to estimate what the impacts of the three alternatives would be at each of the dam locations. Removal of fixed elevation dams may increase or decrease the flood elevation depending on location along the profile, the nature of the impoundment, and the local hydraulics at the site for a range of flood events. Regardless of the alternative used at the site, it will likely require a Letter of Map Revision (LOMR) through the Federal Emergency Management Agency (FEMA). The LOMR is needed for both increases and decreases to the existing base flood elevations. If an increase in the base flood elevation is needed, easements will have to be secured from adjacent property owners who are affected. Wetland impacts will be an important parameter to characterize in the project. Wetland impacts associated with dam removal are evaluated on a case by case basis. Wetlands that have been created as a result of dam construction may be impacted by dam modifications or removal, and mitigation may be required depending on the acres involved and quality of the wetlands. 4.3.2 Reservoir Sediment The correct characterization and understanding of reservoir sediments is the largest factor governing dam removal. Because dam bridging would have limited impact on upstream sediment transport, this discussion is mainly pertinent to full removal options. Reservoir sediments must first be evaluated for contamination. If material is deemed to be contaminated, the options for_ removal are likely limited to those that involve full removal of all contaminated material after drawdown or suction dredging material prior to dewatering the reservoir. This situation represents the most costly project scenario. If it is determined that the sediment is not contaminated, the next concern is prevention of-transport of the material downstream. There are no models currently available to accurately predict the movement and transport of reservoir material following a dam removal. The DREAM model developed by UC- Berkeley and Stillwater Sciences has made some inroads to model transport following dam removal; however it has been developed for non - cohesive silt, sand, and gravel situations, which do not often exist in Midwestern impoundments. HEC -6 has been used in the past to model transport, but it is incapable of accurately modeling the steep slope that results once the dam is removed and the knickpoint begins to move upstream Cui, et al., in press). Until actual sediment data are available, assumptions on the sediment handling options are necessary. In the early 1990s, the sediment above the Graue Mill Dam was removed and was not deemed contaminated at that point in time, so it is reasonable to assume that would still be the case today. A requirement of minimizing sediment from being carried downstream means the sediment must be removed mechanically, at least in the natural channel. 4.3.3 Flood Impact As mentioned above in the permitting section, quantifying the flood impact of any project on the dams being studied is also necessary. As the dams on Salt Creek are low head dams, that are DRSCW - 4 - April 2009 4 DO Improvement Feasibility Study Salt Creek 4.0 Screening for Dams operated full, there will be little impact on the floodplain, either upstream or downstream. However, this will be verified using the most current flood level analysis tool available from DuPage County as part of any design changes. DRSCW - 5 - April 2009 DO Improvement Feasibility Study Salt Creek 5.0 Screening for Stream Aeration 5 SCREENING FOR STREAM AERATION Numerous aeration technologies have been developed and utilized to increase dissolved oxygen (DO) in water. Oxygen transfer efficiency (OTE) is the amount of oxygen that is absorbed by (dissolved into) water during the aeration process divided by the amount of air or oxygen applied to the water. The difference between the saturated DO concentration and the DO of the water column is termed the "DO deficiency "; OTE is directly proportional to the DO deficiency. The higher the water temperature is the lower the DO saturation value. The lower the DO saturation value, the lower the DO deficit (DOsaturation - DOstream), and the less efficient oxygen transfer becomes with air. Where the design specifies a minimum DO of 5 mg /L, aeration is required. At 25 degrees C, the DO saturation is only 8.2 mg /L, so the DO deficiency is 8.2 -5.0 mg /L or 3.2 mg /L. If the aeration were installed where the river reaches 3.5 mg /L, the DO deficit would be 4.7 mg /L, or 47 percent higher OTE than where the initial DO is 5.0 mg /L. This limitation is a drawback to air -based systems. Available technologies can be divided into three categories: Air - Based Alternatives, High- Purity Oxygen Alternatives, and Side - Stream Alternatives. Subsections 5.1, 5.2 and 5.3 briefly describe various technologies and subsection 5.4 provides an overview of the screening process. 5.1 Air -Based Alternatives The following air -based alternatives are grouped into Simple Aeration, Mechanical Aeration, and Bubble Aeration. 5.1.1 Simple Aeration Often associated with stream elevation changes, simple aeration exposes water to the atmosphere as it drops and /or splashes into a lower pool. As a result, oxygen is entrained and the DO concentration is increased as the water loses elevation. Examples of simple aeration devices include weirs, inclined corrugated sheets, splashboards, cascade aerators, multiple -tray aerators, towers, and columns. The existing dams in Salt Creek also show simple aeration as water travels over the spillways and into the plunge pool, replacing some of the DO consumed in the impoundment.. If suitable elevation changes are not present to create aeration, which is the case on Salt Creek, elevation can be created using pumping to transfer water to an aeration device. In general, implementation of this technology will require; land along the shoreline for installation, a power source for pumping, permitting, and maintenance access. The advantages to simple aeration alternatives include relatively low operation costs, ease of construction (in some cases), and limited moving parts to service. The main disadvantages include higher maintenance costs to remove debris collection or clogging and a limitation on how much oxygen can be physically transferred, generally meaning that multiple installations are required. Oxygen transfer efficiencies for these alternatives are low -to- moderate. Specific efficiencies are dependent on the height of the elevation drop or the height of the aeration device, water velocity, and the initial DO concentration. DRSCW - 1 - April 2009 DO Improvement Feasibility Study Salt Creek 5.0 Screening for Stream Aeration 5.1.2 Mechanical Aeration Mechanical aeration is achieved with devices that create movement in the water, via splashing or agitation, convection, or circulation between the top and bottom of the water column. Most mechanical aerators are designed to operate at or near the surface of the water column and draw water up into the air, but some aerators may be submerged and function by drawing the oxygenated surface water to the bottom of the water column. Common examples of mechanical aeration include paddlewheels, spray aerators, propeller- aspirator aerators, and jet aerators. Implementation of these devices may require site considerations for constructability, availability of an electrical source, permitting due to navigational impacts, placement of equipment and access for maintenance and operation. All mechanical aerators require electrical power and continuous maintenance on working parts. Advantageous features of mechanical aeration devices include the ability to be placed within pooled areas thereby minimizing land impact, the ability to be placed along the flow path to maintain a desired DO, and generally lower cost for implementation. Disadvantages of mechanical aeration include the need for a continuous power source to each unit, operational costs for power consumption, generation of noise during operation, possible safety issues, potential for navigational impacts, maintenance for debris removal, sediment disturbance, and susceptibility to damage during flood -stage conditions. In general, oxygen transfer efficiencies for ,these devices are low -to- moderate when trying to maintain DO levels above 5 mg /L. Figure 5 -1 - Mechanical Aeration Display 5.1.3 Bubble Aeration Bubble aeration consists of utilizing blowers or air compressors on the shoreline to introduce bubbles into the water column through air diffusers. The generated air stream is delivered via piping or tubing to air diffusers at the bottom of the water column. In general, air is forced through the diffuser resulting in a release of small bubbles into the water. In order to install DRSCW - 2 - April 2009 DO Improvement Feasibility Study Salt Creek S. 0 Screening for Stream Aeration bubble aerators, site considerations may be required for constructability, the thickness of the bottom sediment, availability of an electrical source, equipment, and periodic access for maintenance and operation. Figure 5 -2 - Bubble Aeration Advantages of bubble aeration include the ability to be placed in existing conditions with relative ease, minimal impacts from floating debris and flood -stage conditions, widely serviceable components for repairs, and the ability to operate in series. Disadvantages of bubble aeration include the need for a continuous power supply and the potential that sediment transported during heavy rain events will bury the tubing.. Oxygen transfer efficiencies are a function of water depth, from poor at shallow depths (less than 3 ft) to moderate at depths ranging from 5 to 6 ft (1.5 -1.8 in ). The efficiency of bubble aeration systems is also dependent on the initial DO concentration. 5.2 High Purity Oxygen Alternatives High - purity oxygen alternatives for increasing dissolved oxygen are based on contacting the water column with a concentrated source of oxygen, with or without pressure above ambient atmospheric conditions. This concentrated or high - purity oxygen source is generally 90 to 99 percent oxygen versus the atmospheric percentage of around 21 percent. High - purity oxygen applications generally utilize on -site storage of oxygen in liquid form. Specialized liquid oxygen vessels store the oxygen under pressure and utilize on -site vaporization to convert liquid oxygen to gaseous oxygen. Site piping is also required to distribute the gaseous oxygen to the various contact methods. As an altern ative to liquid storage, on -site oxygen generators can be utilized to provide a source of high purity oxygen; however, given the seasonality in the need for the oxygen, on -site generation is not cost competitive with on -site storage. High - purity oxygen systems differ from atmospheric systems due to the nearly five -fold increase in oxygen concentration in the gas and the higher gas pressure that can be utilized. In high - purity oxygen systems with increased pressure and oxygen concentration, the water can readily reach DO concentrations up to 100 mg /L as compared to less than 8 mg /L with air systems in the summer months. High - purity oxygen systems can achieve OTE in excess of 80 percent, and DRSCW - 3 - April 2009 d'C �� 4 - �' - .�•s� � —RIVER BANK "¢ �e d �r AIR ! t' F ,`U•��t� + , � �71.AN �'FCg+�r ft�; .y; ��r' �j.QY�Ii�(`�. �f�� F� i 'u �F, :i ". f�9��li,;K 1 � e� ,art Figure 5 -2 - Bubble Aeration Advantages of bubble aeration include the ability to be placed in existing conditions with relative ease, minimal impacts from floating debris and flood -stage conditions, widely serviceable components for repairs, and the ability to operate in series. Disadvantages of bubble aeration include the need for a continuous power supply and the potential that sediment transported during heavy rain events will bury the tubing.. Oxygen transfer efficiencies are a function of water depth, from poor at shallow depths (less than 3 ft) to moderate at depths ranging from 5 to 6 ft (1.5 -1.8 in ). The efficiency of bubble aeration systems is also dependent on the initial DO concentration. 5.2 High Purity Oxygen Alternatives High - purity oxygen alternatives for increasing dissolved oxygen are based on contacting the water column with a concentrated source of oxygen, with or without pressure above ambient atmospheric conditions. This concentrated or high - purity oxygen source is generally 90 to 99 percent oxygen versus the atmospheric percentage of around 21 percent. High - purity oxygen applications generally utilize on -site storage of oxygen in liquid form. Specialized liquid oxygen vessels store the oxygen under pressure and utilize on -site vaporization to convert liquid oxygen to gaseous oxygen. Site piping is also required to distribute the gaseous oxygen to the various contact methods. As an altern ative to liquid storage, on -site oxygen generators can be utilized to provide a source of high purity oxygen; however, given the seasonality in the need for the oxygen, on -site generation is not cost competitive with on -site storage. High - purity oxygen systems differ from atmospheric systems due to the nearly five -fold increase in oxygen concentration in the gas and the higher gas pressure that can be utilized. In high - purity oxygen systems with increased pressure and oxygen concentration, the water can readily reach DO concentrations up to 100 mg /L as compared to less than 8 mg /L with air systems in the summer months. High - purity oxygen systems can achieve OTE in excess of 80 percent, and DRSCW - 3 - April 2009 FINE BUBBLE- TUBING - -.� �� - �' - .�•s� � —RIVER BANK ,`U•��t� + , � �71.AN �'FCg+�r ft�; .y; ��r' �j.QY�Ii�(`�. �f�� F� i 'u �F, :i ". f�9��li,;K 1 � Figure 5 -2 - Bubble Aeration Advantages of bubble aeration include the ability to be placed in existing conditions with relative ease, minimal impacts from floating debris and flood -stage conditions, widely serviceable components for repairs, and the ability to operate in series. Disadvantages of bubble aeration include the need for a continuous power supply and the potential that sediment transported during heavy rain events will bury the tubing.. Oxygen transfer efficiencies are a function of water depth, from poor at shallow depths (less than 3 ft) to moderate at depths ranging from 5 to 6 ft (1.5 -1.8 in ). The efficiency of bubble aeration systems is also dependent on the initial DO concentration. 5.2 High Purity Oxygen Alternatives High - purity oxygen alternatives for increasing dissolved oxygen are based on contacting the water column with a concentrated source of oxygen, with or without pressure above ambient atmospheric conditions. This concentrated or high - purity oxygen source is generally 90 to 99 percent oxygen versus the atmospheric percentage of around 21 percent. High - purity oxygen applications generally utilize on -site storage of oxygen in liquid form. Specialized liquid oxygen vessels store the oxygen under pressure and utilize on -site vaporization to convert liquid oxygen to gaseous oxygen. Site piping is also required to distribute the gaseous oxygen to the various contact methods. As an altern ative to liquid storage, on -site oxygen generators can be utilized to provide a source of high purity oxygen; however, given the seasonality in the need for the oxygen, on -site generation is not cost competitive with on -site storage. High - purity oxygen systems differ from atmospheric systems due to the nearly five -fold increase in oxygen concentration in the gas and the higher gas pressure that can be utilized. In high - purity oxygen systems with increased pressure and oxygen concentration, the water can readily reach DO concentrations up to 100 mg /L as compared to less than 8 mg /L with air systems in the summer months. High - purity oxygen systems can achieve OTE in excess of 80 percent, and DRSCW - 3 - April 2009 DO Improvement Feasibility Study Salt Creek 5.0 Screening for Stream Aeration achieve supersaturated levels across the entire stream. The result is that fewer installations are needed with this technology to maintain a defined DO level along the entire stream. This subsection outlines alternatives that have been developed to increase dissolved oxygen concentrations utilizing high - purity oxygen. For this discussion, alternatives are grouped into simple oxygenation and bubble oxygenation. For high - purity oxygen, the term oxygenation will replace aeration as an indication of the high purity versus the atmospheric source of oxygen. 5.2.1 Simple Oxygenation using High - Purity Oxygen Simple oxygenation devices increase DO concentrations by allowing oxygen - deficit water to contact high - purity oxygen as it flows through a sealed chamber. As water drops from the top of the chamber to the bottom, a gas /liquid interface is created by contact between the water and the oxygen source. Low head oxygenators (LHO) and sealed columns are two examples of devices that can be utilized with high - purity oxygen. These alternatives would most likely be applied in a side - stream setting with pumping due to limitation of sufficient gradient change necessary to drive water through the devices, flow requirements, and navigational issues. Installation of these devices may require site considerations for constructability, maintenance and operation access, storage of supplies, and storage of liquid oxygen. Advantages of these alternatives include high oxygen transfer efficiency, ease of construction, little navigational impact, and low maintenance due to a limited number of working parts. Disadvantages include potential for debris collection and clogging of the water intake structure, similar to any side - stream technology, and DO levels achieved in the side - stream will be limited to approximately 40 mg /L as they are operated at atmospheric pressures. . Figure 5 -3 - Low Head Oxygenators 5.2.2 Pressurized Oxygenation Using High - Purity Oxygen DRSCW - 4 - April 2009 DO Improvement Feasibility Study Salt Creek 5.0 Screening for Stream Aeration Again using the side - stream approach, but with sealed vessels, the oxygen and water can be introduced at pressures near 100 psig. The solubility of oxygen is proportional to the pressure as well as the oxygen content of the gas feed, so DO levels near 100 mg /L can readily be achieved. This reduces the pumping rate of the withdrawn water, but requires a rapid mix diffuser on the discharge back into the waterway to dissipate the highly enriched oxygenated water before the oxygen is lost to the atmosphere. Oxygenation systems include aeration cones, serpentine pipe mixers, and simply longer runs of pipe with a pressure let down device on the discharge end (for example, eductors). Installation of these devices will require site considerations for constructability, maintenance and operation access, and storage of supplies and liquid oxygen. Both the intake and discharge ends will require routine maintenance to remove debris. Advantages to pressurized oxygenation devices include low navigational impacts, high oxygen transfer efficiencies, high efficiency at low water depths, and the ability to operate in varying water flows. A disadvantage is the maintenance on the water intake and discharge end. Figure 5 -4 - Diffuser Used for Bubble Aeration 5.3 Air Supplied Side - Stream Alternatives Aeration of side - streams is another technique that can be utilized to increase DO concentrations. Side stream applications involve partitioning a portion of the total river flow off and increasing the dissolved oxygen concentration in that portion. To maintain DO levels above 5 mg /L, water withdrawal rates will approach 30 to 50% of the stream flow at low flow conditions, as opposed to only 5 to 10 percent with high - purity oxygen. Higher DO increases are associated with larger volumes of water contacted with the alternative, but fewer overall installations. Specific side - stream applications include side - stream elevated pool aeration (SEPA), pressurized side - stream columns, side - stream channels, and bubble -free aeration; however, all alternatives outlined above can also be implemented as a side - stream alternative with the construction of a side - stream channel adjacent to the existing main riverbed. Advantages of the side - stream applications include potential for community amenity (SEPA has been implemented in the Chicago Metro DRSCW - 5 - April 2009 DO Improvement Feasibility Study Salt Creek 5.0 Screening for Stream Aeration area and has become a popular attraction), a reduced column of water needed for direct addition of air or oxygen, control over flow conditions, and enhanced ability to supersaturate when utilizing high - purity oxygen (in some cases). Disadvantages include the need for elevation changes necessitating pumping, more fish impingement and entrainment as a result of the larger pumping rates, and the necessity to acquire space adjacent to the main river channel. Figure 5 -5 - Side - Stream Aeration Facility 5.4 Overview of Aeration Feasible Alternatives From Sections 2 and 3, the lowest DO levels on Salt Creek occur within the impoundment above the Graue Mill Dam. Low DO values have also been noted near Butterfield Road; however, at this location the stream channel has been excessively widened and this could be corrected by restoring the natural channel through this area. In addition, limited DO data above the Oak Meadows dam indicates that lower DO levels also occur in this stretch, the modeling results are consistent with these observations. From a priority perspective, the lowest DO reach should be addressed first, which is the Fullersburg Impoundment above the Graue Mill Dam. The quiescent conditions within the impoundment are ideal for oxygen systems, as minimum DO will be lost to the atmosphere within the impoundment under supersaturated conditions, at least until the water overflows the dam. Side - stream air systems are also possible, but will require pumping rates that will approach the daily flow in Salt Creek. However, the SOD within the impoundment may necessitate more than one side - stream to maintain the DO level above 5.0 mg /L. Bubble diffusers laid parallel to the flow within the impoundment would also be a viable option, assuming the diffusers do not get covered in silt during high -flow periods. This would have to be demonstrated initially. Surface aerators are not recommended due to aesthetic and maintenance perspectives. DRSCW - 6 - April 2009 DO Improvement Feasibility Study Salt Creek 5.0 Screening for Stream Aeration In all cases, the aeration device would be operating in the evening hours. Once photosynthesis begins in the mid - morning, the DO levels would remain above 5.0 mg /L until the early evening hours, when the aeration system would be restarted. Finally, the question of ownership and operating /maintenance responsibilities will need to be addressed, if this approach is selected. There are electrical costs, potentially oxygen costs, and on -going labor for operation and maintenance. Unlike a dam removal/bridging project, which is basically a one -time cost for removal /modification, in- stream aeration will have on -going costs in perpetuity. DRSCW - 7 - April 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation 6 EVALUATION The Workgroup started out to improve on the stream DO model used by IEPA for Salt Creek, from which alternatives for improving the DO in Salt Creek could be evaluated. It soon became clear that better data inputs for the model development were necessary. Two years of excellent continuous summer DO data have now been generated, along with SOD data collected over the summers of 2006 and 2007. The result is a model that reasonably predicts observed DO and can reasonable predict conditions during low flow, warm weather conditions. Con - currently with these DO data collection efforts, the Workgroup collected extensive fish, macroinvertebrate and habitat data on Salt Creek. Analysis of the continuous stream DO monitoring, the DO modeling, and the biological survey data all yield similar findings; that is, the Graue Mill Dam is the single largest impediment to improved water quality and aquatic community integrity on Salt Creek, followed by the Oak Meadows Dam and the wide channelization at Butterfield Road. From a priority perspective, improvements in low flow DO levels should focus on these three areas, in this order. At the Old Oak Brook Dam, the baseline model predicts DO levels during low flow - warm conditions will drop to a minimum of 4.1 mg/L, as compared to the minimums predicted above the Oak Meadows Dam of 3.6 mg/L and above the Graue Mill Dam of 1.2 mg/L. Continuous monitoring at Butterfield Road in 2008 revealed minimum DO values on the order of 2.5 mg/L during low flow conditions. Restoring this stretch to a more natural channel and addressing the low DO values above the Oak Meadows and Graue Mill Dams will result in more benefit to the stream than the lower DO values caused by the Old Oak Brook Dam. To improve the DO levels within the impoundments, there are a number of options: Complete dam removal; Periodic dredging; Partially breach the dam; Bridge the dam; and In- stream aeration. Given the historic value of the Graue Mill Dam, complete dam removal was not considered a viable option. Periodic dredging would require dredging on a two -year cycle, and would little for improving the biological stream characteristics. Within the Fullersburg Woods Impoundment, the sediment accumulation rate is on the order of 10,000 cu yd per year. To remove this sediment would cost on the order of $400,000 per year. From both a cost and biological perspective, this option was also rejected. Partially breaching the dam or enhanced bridging, if done correctly, have the added advantages of allowing fish passage and habitat improvements. Simply raising the DO level within the impoundments via aeration will neither allow fish passage or improvements to feeding and breeding conditions upstream, As discussed in Section 5, dam removal /bridging is a one time cost, while aeration has capital and on -going operating/maintenance cost components. As discussed in Section 3, a baseline model was developed based on peak temperature data collected over the most recent ten years and actual 2005 summer pollutant loadings from the POTWs. The model was then used to evaluate the DO levels that can be achieved from alternatives including dam removal/bridging and in- stream aeration, focusing in on the two most DRSCW 6 -1 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation significant impairments to DO, the Graue Mill Dam and the Oak Meadows Dam. In addition, an alternative model was run assuming all of the pollutant loading from the wastewater treatment plants is removed from Salt Creek, while flow is held constant. 6.1 Baseline Model Figure 6 -1 presents the baseline conditions, as previously presented in Section 3. This baseline assumes average summer pollutant loadings from the wastewater treatment plants (based on 2005 summer data) and maximum stream temperatures, based on historical data. To achieve the DO water quality standards, the minimum DO is to be maintained above 5.0 mg/L through July 31'` each year. The minimum DO is located just above the Graue Mill Dam, where minimum DO values of 1.2 mg/L will occur. Above the Oak Meadows Dam, minimum DO levels are predicted to reach 3.6 mg/L, and above the Old Oak Brook Dam, minimum DO levels are predicted to reach 4.1 mg/L. Details on the input to the Baseline Model are provided in Section 3 and Appendix B. 11 10 B B 7 �Jf E 6 0 0 5 4 3 2 1 0 F- 50 Salt Creek malnstem Monthly Average of June 2005 DMR Condition with 3 ° C Increased Plant Discharge and Air Temperature Oak Meadows Golf Course dam Old Oak Brook darn FuBersburg Woods Dam (Grace MdQ a b c d e f9 e------ :----------- - - - - -- - -- ------------------------ - - - -- r- - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- G - - - - - - - 4 - - % oe -- ------- - - - - -- - - - - - - - - - - - - - ,- - - - - - - - - ---- �' - - - - - f - - - - - - - ♦� - - ° B- - - - - °°°- F - - -- - - - - - - - - '- ---- - - - - -- :s- - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - C _ ._ .:a_ _ _ _ - _ _ - _ _ _ - - _ - _ _ -- - -- ?� - - - - - - -- - - - - - - - - - - - - - - - - - -- - �- ', - �- - - - - - - - - - -" -' - - -- - - - - -- 21� ® 4 - - - - - — - - ` -- - - - - - - - - - - -- - �� - - - - -- 45 40 35 30 25 20 15 10 5 0 Distance from downstream (km) —DO(mg021L) -- m DO(mg=L) Min °- - DO(mg02/L) Max - - DO sat a Point Source Figure 6 -1. Baseline Dissolved Oxygen for Salt Creek 6.2 Alternative 1: Eliminate Pollutants in Wastewater Treatment Plant Effluents For reference purposes, the model was run assuming the wastewater treatment plants maintain their discharges to Salt Creek but reduce all oxygen demanding pollutants and nutrients from their effluents. Figure 6 -2 presents a comparison of the baseline model (current worst conditions) to the predicted minimum DO profile. The model predicts improvements to greater than 5.0 mg/L above the Oak Meadows Golf Course and above the Old Oak Brook Dam. Above the Graue Mill Dam, minimum DO is predicted to improve from 1.2 mg/L to 3.8 mg/L. From DRSCW 6 -2 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation this simulation, even without any point source pollutants but maintaining flow, the Fullersburg Woods impoundment will not achieve the Illinois DO water quality standard. In addition it important to note that this alternative does nothing to alleviate the impairment to habitat caused by the dam impoundment and the negative impacts on fish migration posed by the dam. 8 7 6 5 O 4 0 3 2 1 0 50 Daily Minimum Dissolved Oxygen vs. Downstream Distance Evaluation Scenarios 1 -No Pollutant Loading from POTWs Oak Meadows Golf Course dam Old Oak Brook dam Fullersburg :Moods Dam (Graue Mill) a b ( d a f 9 I I ♦ Point Source Locations t I I I I I DO Standard (above 5 mg /L at any tim ( ( � I i i------------ - - - - -- - - - -- -------------------------- - - - - -- -- -- -- -- -- i -- — - -- -- - -- ---------- - - - - -- -------------- I _ I _ I I - Baselvre - No Font Source Lcadmps I I i 45 40 35 30 25 20 15 10 5 0 Downstream Distance (km) Figure 6 -2. Baseline Minimum D.O. vs. Downstream Distance Table 6 -1 presents the estimated costs for achieving essentially zero pollutant discharge. Each of the plants were assumed to be retrofitted with Membrane Bioreactors and polished with granular activated carbon. The estimated capital cost is in excess of $200,000,000. No estimate of operating costs was made, given the large capital cost and the predicted minimum DO below 5 mg/L in the Fullersburg Woods Impoundment. DRSCW 6 -3 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation TABLE 6 -1 SALT CREEK POTW UPGRADE ESTIMATE CAPITAL COST FOR MBR & GAC ADDITIONS Plant Design Average Flow, MGD Design Max Flow, MGD MBR @ $2 /Gal GAC �a, $1.50 /Gal Per Plant Total Egan 30.00 50.00 _ $100,000,000 $7550005000 $175310001000 Nordic Park 0.50 1.00 $2300031000 $11500,000 $3750011000 Itasca 2.60 10.00 $207000P0 000 $15, 000, 000 $35)000.1000 Wood Dale N 1.97 3.93 $77860,000 $51,8951,000 $13317553,000 Wood Dale S 1.13 2.33 $4,6601000 $3,49511000 $8,15511000 Addison N 5.30 7.60 $1512001P000 $11,400,000 $26,6002000 Addison S 3.20 8.00 $16110001000 $1270001P00 $28, 000, 000 SC SD 3.30 8.00 $16,0001000 $12,000,000 $28,000,000 Elmhurst 8.00 20.00 , $4010001000 $301000,000 $7020001,000 $38811010,000 6.3 Alternative 2: Dam Crest Drop or Bridging (Graue Mill Dam) and Removal (Oak Meadows Dam) Alternative 2 was prepared, assuming dam removal in the case of Oak Meadows, and the lowering of the Graue Mill Dam by 1 ft, 2 ft, and 3 ft. Figure 6 -3 presents the minimum DO profile under the various dam removal/bridging options, along with the baseline DO profile. The model predicts the minimum DO above Oak Meadows will still reach below 4.0 mg/L. This is a location where additional monitoring data would be appropriate. The model predicts that this drop in DO happens nearly 2.5 RM (4 km) above the Oak Meadows Dam. This output is suspect, as there is a wastewater treatment plant discharge (the Itasca POTW) at RM 25.9 (km 41.4), or 3.0 miles (4.8 km) above the Oak Meadows Dam. More recent DO data from the Itasca POTW indicates a minimum DO effluent level of 6 mg/L, and one would expect some distance before 5.0 mg/L would be reached. In addition, this POTW is currently undergoing a significant upgrade that will result in a higher quality effluent than is currently being attained. Below this wastewater treatment plant there is excellent canopy cover until the Oak Meadows Golf Course, conducive to minimizing algal growth. Only two SOD results have been collected above the Oak Meadows Dam at RM 23.0 and 22.9 (37.0 and 36.8 km), one a low 0.5 g/m2 /day and the second 2.27 g/m2 /day. The model used the highest of these two values, which is likely unrepresentative of the average SOD conditions. At the Graue Mill Dam, lowering the crest one foot improves the minimum DO to 4.0 mg/L (from 1.2 mg/L), and lowering the crest two feet improves the minimum DO to 5.2 mg/L. If the crest is lowered three ft, the minimum DO is predicted to remain above 6.0 mg/L. Thus, a reduction in crest height of 2 ft at the Graue Mill Dam would result in achieving the Illinois DO water quality standards, while at the Oak Meadows Dam, the model predicts there will still be minimum DO levels below the 5 mg/L. DRSCW 64 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation v 01 O 4 O Daily Minimum Dissolved Oxygen vs. Downstream Distance Evaluation Scenario 243am Removaif8ridging Oak Meadows Gal {Course dam Old Oak Brook dam Fullersburg `Hoods Dam (Grave Mill) a b c d e f 9 ! ♦- Point Source Locations ---------- -------- ---- --- ---- --- --- --- -- ------- ------ -------- — --- ----- ---------- — DOStandard(above6mg)Latanytime) - - -------- - - — Baseline — 2 Dams RemDVed Dam Bridging t (dam crest lowered by t ft) — — -- -- - - "- -- _ ' — Dam Bndgmo 2 (dam crest lowered by 2 ft) i — Dam Bridging 3 (dam emst lowered by 3 ft) 50 45 40 35 30 25 20 15 10 Downstream Distance (Km) Figure 6 -3. Dam Removal Minimum D.O. vs. Downstream Distance 6.3.1 Oak Meadows Dam Removal Aside from needing to perform the project without impinging on golfing operations at the site, the full removal of the Oak Meadows Dam is a simple project and the cost estimate reflects that. The dam itself can be fully removed and the former abutments restored to either match the existing bank treatment (a jacks on the right and steel sheet pile on the left) or graded for a more natural appearance. Sediment impounded by the dam can likely be stabilized in -situ with careful removal of the dam, and limited excavation will be needed. Some riparian planting upstream within the dewatered channel was assumed in this estimate, though may be either eliminated or enhanced depending on the management goals. Upstream impacts to golf course irrigation ponds may require mitigation if the existing water source is to be used. Incidental bank grading and stabilization as a result of removal was also not accounted for, but should represent a minor contingency in the budget. Sediment behind the dam is assumed to be clean of contaminates that would require special handling. The planning level estimate for design and construction of this project includes $60,000 for design and permitting and $190,000 for construction, or a total capital cost of $250,000. The on shore work would occur during the non - golfing season, mid - November to early April, while the in stream work would need to be done during the lower flow - warmer conditions. There would be no on -going operations or maintenance costs. DRSCW 6 -5 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation 6.3.2 Graue Mill Dam Given the historical and aesthetic value placed on this dam to the community, complete dam removal at this location was not considered as an option beyond the act of modeling. The two options that were considered at the site are bridging or a partial breach. This dam presents a more complex project than the Oak Meadows Dam with associated changes to wetlands and aesthetics that exist currently as a result of the dam. For the purposes of simplifying the cost estimation, given the uncertainty associated with the two approaches presented, a few assumptions were made. First, no active restoration of the channel above the dam was assumed in the estimate. The upstream channel can be actively or passively restored based on the management goals of the Forest Preserve District of DuPage County. Second, an estimate for any modification to the existing sluice way required to provide head to drive the water wheel was not included in the estimate, since specific solutions to this have not been investigated in detail. Last, any amenities, including adding a recirculating pump to spill water over the remaining crest of the dam (under the breach option) were not included. The cost estimates for both alternatives assume approximately $200,000 for design and permitting, variations in this cost are expected to be minor between the two options. Costs for seeding and dealing with invasive plant species have not been included in the estimate. Bridging would lower the crest of the dam by approximately 2 to 3 feet and fill the downstream face with rock, creating a riffle or bridge between the upstream and downstream sections. A new water surface elevation upstream would result in the need for riparian re- vegetation and control of invasive species. Since the spillway would be back filled with rock on the downstream side, additional buttressing to address stability of the dam would not be required. The rock fill would be rounded, glacial stone, representing a substantial portion of the overall construction budget. Estimated costs for the design and construction of the bridging option range from $800,000 — $1,100,000. Figure 6 -4 depicts the footprint of the Fullersburg Impoundment under the various lowering of the dam height scenarios. DRSCW 6 -6 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation Figure 6 -4. Fullersburg Woods Footprint with Lowered Dam Elevations A partial breach of the dam would occur on the left (north east) bank, removing the existing dewatering structure and removing a portion of the existing dam. The amount of exposed (former) impoundment upstream of the dam would be larger than under the bridging option and represents a substantial portion of the estimated cost. Again no channel restoration upstream of the existing dam is assumed in this scenario. The estimated cost range for designing and constructing a partial breach of the dam is $300,000 - $600,000. Figure 6 -5 depicts the stream channel through the area of the Fullersburg Woods Impoundment if the dam is breached. DRSCW 6 -7 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation Graue Mill Dam, Partial Breaching Option Current conditions at dam Current reservoir before before partial breaching partial breaching, looking upstream Dam after proposed partial Reservoir after paoposed breaching partial breaching looking upstream Figure 6 -5. Fullersburg Woods Footprint with Breaching Option Depending on the final design there would also be perpetual operating costs associated with pumping if utilized for the water wheel and/or to pass over the spillway. These costs are estimated at $20,000 per year. 6.4 Alternative 3: In- strew Aeration Using Air -Based 'Technology In- stream aeration is presented as Alternative 3, and the resulting DO trend is depicted in Figure 6 -4 for the daily minimum prediction using air -based technology. Raising the DO levels from 5.0 to 6.0 mg/L at a single location above each dam results in some improvement in overall DO levels but does not achieve state water quality standards through the entire length that is below the 5.0 mg/L level. 6.4.1 Oak Meadows Golf Course Dam As discussed previously, any supplemental aeration technology needs to be applied at locations where the DO first dips to 5.0 mg/L, and the modeling predicts this happens nearly 4 km above the Oak Meadows Dam. As noted previously, this location is suspect as there is a wastewater DRSCW 6 -8 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation treatment plant discharge (the Itasca POTW) at RM 25.9 (41.4 km), or 3 miles (4.8 km) above the Oak Meadows Dam. More recent DO data from the Itasca POTW indicates a minimum DO effluent level of 6 mg/L, and one would expect some distance before 5.0 mg/L would be reached. In addition, this POTW is currently undergoing a significant upgrade that will result in a higher quality effluent than is currently being attained. Below the POTW there is excellent canopy cover until the Oak Meadows Golf Course, and algal and plant growth in the stream would be expected to be minimal under this canopy cover. The shallow nature of the stream above the Oak Meadows Dam limits the possible air -based technologies. If side - stream aeration is selected, the withdrawal rate will be approximately 50% of the low flow, or 14 MGD (0.6 m3 /s). Such a high withdrawal rate will require a fine screen to avoid fish impingement, and with the debris that accumulates on the screen an automatic cleaning screen will be necessary. Fine bubble tubing, as illustrated in Figure 5 -2, would avoid the potential for fish damage and high maintenance for the screen. Approximately 1,200 ft of fine bubble tubing would be necessary above Oak Meadows to raise the DO from 5.0 to 6.0 mg/L and a 10 HP blower plus one spare would be required. The blowers would be housed in a small building with a header laid on the floor of the Salt Creek, with the tubing extending downstream. Tubing runs of 300 ft are acceptable, therefore, there would be 4 aeration tubings extending downstream. Figure 6 -6 presents the improvement with air -based technology. The model predicts the minimum DO drops below 5.0 mg/L 3.1 miles (5 km) above the Oak Meadows Dam. In an ideal situation, this is where the in- stream aeration would be located. However, this is within a wooded area without access or power currently. As noted previously, the SOD value used above this dam in the model was the higher of only two results, and therefore may be overly conservative. Above Oak Meadows a potential location for this would be at the north end of the Oak Meadows Golf Course, along Elizabeth Drive, approximately 0. 94 miles (1.5 km) above the Oak Meadows Dam. There would be access here, and power could be run in from along Addison Road. From the modeling, if the DO is raised from 5.0 to 6.0 mg/L at this location, the benefit would carry 0.8 stream miles (1.3 km) downstream. From an accuracy perspective, this would carry the DO improvement to within 0.14 stream miles (0.2 km) of the dam, so DO would be expected to remain above 5.0 mg/L in all but the warmest extended periods. This location is also the beginning of where minimum DO values actually fall below 5.0 mg/L, due to the lack of canopy cover through this stretch of Salt Creek. DRSCW 6 -9 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation ill SO 6 0 6 Salt Creek (8/15/2006) Mainstem Aeration Altematfve 3 in Oak Meadows Dam and Graue Mill Darn Impoundments Oak Meadows Gulf Course dam Old Oak Brook dam Fullersburg Woods Dam (Graue Mill) s `a b o d °- f 9 I If �� r ^� DO Standard (sboAn 5 mg,L atanytims) In -stream Aeration - In -stream Aeratio J� 50 45 40 35 30 26 20 15 10 Distance from downstream (km) 00(mg021L) - -- 00(mg021L)Min - -- 00(mgQ2/L) Max a Point Source Figure 6 -6. Aeration Alternative Minimum D.O. vs. Downstream Distance The capital cost for a single installation above Oak Meadows is estimated at $470,000 and the annual operating cost would be $100,000 per year. The net present value over 20 years would be $1,190,000, assuming only one installation is necessary. If a second air -based system is necessary, these costs would nearly double, to $800,000 capital and a net present value of $2,050,000. The cost for one installation above Oak Meadows is presented in Table 6 -2. 6.4.2 Graue Mill Dam In the Fullersburg Woods impoundment, the minimum DO drops below 5.0 mg/L approximately 1.25 stream miles (2.0 km) above the Graue Mill Dam. Two air -based instream aeration systems will be required to maintain the DO above 5.0 mg/L with the second one located less than 0.3 miles (0.5 km) above the dam. Within the impoundment, sediment levels are thicker and sediment deposition over the aeration tubing during -the periods not in operation will be a concern. However, the water column depth is greater than above the Oak Meadows Dam, so the oxygen transfer efficiency will be greater. When the aeration tubing is first started up in May /June, re- suspension of sediment will occur for a short period of time. It is likely that the tubing will have to be physically removed each fall, and re- installed in the late spring to maintain its efficiency, which was factored into the costs. Table 6 -3 presents the capital, operating, and net present value for two instream aeration systems in the Fullersburg Woods impoundment. The estimated capital cost is $800,000, and the annual operating cost is estimated at $100,000. The net present value over the next twenty years is $251050,000. DRSCW 6 -10 June 2009 DO Improvement Feasibility Study Salt Creek TABLE 6 -2 INSTREAM AERATION AT OAK MEADOWS USING FINE BUBBLE TUBING AND AIR Assumptions 1) 210 lbs per oxygen transferred per day required, per location 2) Assume 2.2 lbs of oxygen transferred per hr per hp can be achieved 3) Assume average depth of 3 ft attainable at location of tubing 4) Electrical cost in sunnier $.10 per kwhr 5) Target DO not allowed to drop below 5 mg/L in June and July CAPITAL COST Number Units Unit Cost Cost 6.0 Evaluation Land 0.5 acres $ 50,000.00 $ 25,000.00 Blower building 1 bldg $ 60,000.00 $ 60,000.00 Blower piping 150 ft $ 100.00 $ 15,000.00 Blower header 1 header $ 10,000.00 $ 10,000.00 Trenching & Restoration 150 ft $ 40.00 $ 6,000.00 Blowers -10 hp each 4 $ 10,000.00 $ 40,000.00 Bubble diffusers,purchase 1200 ft $ 6.00 $ 7,200.00 Bubble diffuser installation 4 mandays $ 800.00 $ 3,200.00 Electrical 1 $ 60,000.00 $ 60,000.00 Design $ 40,000.00 Permitting $ 10,000.00 WetlandsMitigation $ 20,000.00 Controls & Telemeter 1 each 25000 $ 25,000.00 Access Road 1 30000 $ 30,000.00 Erosion control $ 10,000.00 Sub -Total $ 361,400.00 Contingency 0.3 $ 108,420.00 Total $ 470,000.00 Annual cost Electrical 120 days $18.00 $2,160.00 Operating Labor 320 hrstyr 50 $ 16,000.00 Maintenance 320 hrstyr 50 $ 16,000.00 Replacement Costs 5% of capital $ 23,500.00 Total Annual cost $58,000.00 Net present value over 20 years Capital Cost $ 470,000.00 Present Value from Annual $ 58,000.00 5% 12.466 $ 723,028.00 Net Present Value $ 1,190,000.00 DRSCW 6 -11 rune 2009 DO Improvement Feasibility Study Salt Creek TABLE 6 -3 INSTREAM AERATION AT GRAUE MILL USING FINE BUBBLE TUBING AND AIR Assumptions 1) 325 lbs per oxygen transferred per day required, per station or 650 lb /day total. 2) Assume 2.21bs of oxygen transferred per hr per hp can be achieved 3) Assume average depth of 4 ft attainable at location of tubing 4) Electrical cost in summer $.10 per kwhr 5) Target DO not allowed to drop below 5 mg/L in June and July 6.0 Evaluation CAPITAL COST $ 800,000.00 Annual cost Number Units 120 days Unit Cost Cost Land 1 acre $ 50,000.00 $ 50,000.00 Blower building 2 bldg $ 60,000.00 $ 120,000.00 Blower piping 300 ft $ 100.00 $ 30,000.00 Blower header 2 header $ 10,000.00 $ 20,000.00 Trenching & Restoration 300 ft $ 40.00 $ 12,000.00 Blowers -15 hp each 4 $ 10,000.00 $ 40,000.00 Bubble diffusers,purchase 3000 ft $ 6.00 $ 18,000.00 Bubble diffuser installation 10 mandays $ 800.00 $ 8,000.00 Electrical 2 $ 60,000.00 $ 120,000.00 Design $ 50,000.00 Permitting $ 20,000.00 WetlandsMitigation $ 40,000.00 Controls & Telemeter $ 40,000.00 Access Road 2 30000 $ 60,000.00 Erosion control $ 20,000.00 Sub -Total $ 648,000.00 Contingency 0.3 $ 194,400.00 Total $ 800,000.00 Annual cost Electrical 120 days $54.00 $6,480.00 Operating Labor 700 hrs /yr 50 $ 35,000.00 Maintenance 640 hrs/yr 50 $ 32,000.00 Replacement Costs 5% of capital $ 40,000.00 Total Annual cost $100,000.00 Net present value over 20 years Capital Cost $ 800,000.00 Present Value from Annual # # # # # # # # ## 5% 12.466 $ 1,246,600.00 Net Present Value $ 2,050,000.00 DRSCW 6 -12 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation 6.4.3 Flood Control Reservoirs Use During Low Flow -Warm Conditions Although beyond the current scope of work, the two flood control reservoirs (Wood Dale Itasca Reservoir and the Elmhurst Quarry offer the potential to improve DO levels during the warmer dry weather periods. Routine pumping of groundwater from the Elmhurst Quarry occurs, and the existing outfall passes over a cascading aerator. If pumping could be conducted during the evening hours, flow during the critical diurnal DO periods could be supplemented, bringing in additional oxygen and reducing retention time through areas like Butterfield Road during these similar conditions. Whether a similar approach at Wood Dale Itasca Reservoir could also be done has not been investigated, but has the potential of increasing DO in the stretch above the Oak Meadows Dam would suggest this should also be explored. 6.5 Alternative 4: High - Purity Oxygen The advantage of high - purity oxygen is that higher initial DO levels in the stream are possible, typically up to 150 percent of saturation, resulting in maintaining minimum DO levels above 5.0 mg/L for longer stream reaches. Thus fewer installations are required. Figure 6 -7 depicts the DO profile in Salt Creek, assuming high- purity oxygen injections above Oak Meadows and Crraue Mill Dams. 6.5.1 Oak Meadows Golf Course Dam Raising the DO from 5 to 12 mg/L above Oak Meadows carries 2.5 miles (4 km), so only one installation would be necessary. The capital cost is estimated at $460,000 (Table 6 -4), and the annual operating cost is estimated at $76,000 per year. A total of 110,000 pounds of high- purity oxygen would be injected annually. The net present value over 20 years is estimated at $1,410,000. 6.5.2 Graue Mill Dam In the Fullersburg Woods impoundment, the benefit of oxygen injection carries 1.25 miles (2 km), as depicted in Figure 6 -5. Such improvement would be expected to result in all of the Fullersburg Woods impoundment maintaining minimum DO levels above 5.0 mg/L except for during the warmest prolonged dry periods, when the model predicts DO levels near the dam itself would fall to approximately 3.0 mg/L (compared to 1.2 mg/L currently). The capital cost for a single high -purity oxygen system is estimated at $500,000, and the annual operating cost would be on the order of $97,000. Oxygen injection would be on the order of 330,000 pounds per year. Over a twenty year period, the net present value for oxygen addition at within the Fullersburg Impoundment would be $1,710,000. DRSCW 6 -13 June 2009 DO Improvement Feasibility Study Salt Creek TABLE 6-4 HIGH - PURITY OXYGEN ADDITION AT OAK MEADOWS Assumptions 1)1,456lbs per day required per CW. 2) 02 transfer efficiency of 80 %, so consumption 1,820 lbs per day 3) density of LOX is 9.5 lbs per gal, so consumption will be 290 gallons per day 4) There are 12 cu ft per pound 5) Price of Oxygen is $0.05 per pound 6) Over a four month period, at 1,820 lbs per day, operated 12 hours per day, need 110,000 pounds per yr 7) Lease 2 -6,000 gallon tanks, or 18,000 gallon capacity, or one year supply 8) DO not allowed to drop below 5 mg/L in June and July 9) Assume one system placed at northern edge of golf course CAPITAL COST Number Units Unit Cost Cost Land 0.5 acres $ 50,000.00 $ 25,000.00 Concrete Pads 2 10 x 10 $ 4,000.00 $ 8,000.00 Piping $ 25,000.00 Insulation $ 5,000.00 Trenching $ 8,000.00 Pumps 2 $ 5,000.00 $ 10,000.00 Intake structures 1 $ 20,000.00 $ 20,000.00 Eductors installation 1 $ 30,000.00 $ 30,000.00 Electrical 1 $ 60,000.00 $ 60,000.00 Design $ 50,000.00 Permitting $ 10,000.00 WetlandsMitigation $ 20,000.00 Controls & Telemeter $ 25,000.00 Fencing 1 15000 $ 15,000.00 Access Road 1 30000 $ 30,000.00 Erosion control $ 10,000.00 Sub -Total $ 351,000.00 Contingency 0.3 $ 105,300.00 Total $ 460,000.00 ANNUAL COST Lease 2 -6000 gal Cryogenic tanks 2 6,000 gal $ 6,500.00 $ 13,000.00 Oxygen 110000 lbs $0.06 $6,600.00 Electrical 100 KWhr /day $0.10 $1,200.00 Operating Labor 320 hrs/yr 50 $ 16,000.00 Maintenance 320 hrs/yr 50 $ 16,000.00 Replacement Costs 5% of capital $ 23,000.00 Total Annual cost $ 76,000.00 Net present value over 20 years Capital Cost $ 460,000.00 Presnt of Annual $ 76,000.00 5% 12.466 $ 950,000.00 Net Present Value $ 1,410,000.00 6.0 Evaluation DRSCW 6 -14 June 2009 DO Improvement Feasibility Study Salt Creek TABLE 6 -5 HIGH- PURITY OXYGEN ADDITION AT GRAUE MILL Assumptions 1) 2,200 lbs per day required 2) 02 transfer efficiency of 80 %, so consumption 2,750 lbs per day 3) density of LOX is 9.5 lbs per gal, so consumption will be 290 gallons per day 4) There are 12 cu ft per pound 5) Price of Oxygen is $0.05 per pound 6) Over a four month period, at 2,750 lbs per day need 330,000 pounds per yr 7) Lease 2 -9,000 gallon tanks, or 18,000 gallon capacity, or 62 day supply 8) DO not allowed to drop below 5 mg/L in June and July, system required 24 hour per day 9) Assume one system placed along pool at Fullersburg Woods where DO declines below 5 mg/L CAPITAL COST Number Units Unit Cost Cost Land 0.5 acres $ 50,000.00 $ 25,000.00 Concrete Pads 2 15x15 ft $ 5,000.00 $ 10,000.00 Piping $ 25,000.00 Insulation $ 5,000.00 Trenching $ 8,000.00 Pumps 2 $ 5,000.00 $ 10,000.00 Intake structures 1 $ 25,000.00 $ 25,000.00 Eductors installation 1 $ 50,000.00 $ 50,000.00 Electrical 1 $ 50,000.00 $ 50,000.00 Design $ 50,000.00 Permitting $ 10,000.00 WetlandsMitigation $ 25,000.00 Controls & Telemeter $ 25,000.00 Fencing 1 15000 $ 15,000.00 Access Road 1 40000 $ 40,000.00 Erosion control $ 10,000.00 Sub -Total $ 383,000.00 Contingency 0.3 $ 114,900.00 Total $ 500,000.00 ANNUAL COST Lease 2 -9,000 gal Cryogenic tanks 2 9000 gal 8100 $ 16,200.00 Oxygen 330000 lbs $0.06 $19,800.00 Electical 300 kwh/day $0.10 $3,600.00 Operating Labor 320 hrs /yr 50 $ 16,000.00 Maintenance 320 hrs/yr 50 $ 16,000.00 Replacement Costs 5% of capital $ 25,000.00 Total Annual cost $ 97,000.00 Net present value over 20 years Capital Cost $ 500,000.00 Presnt of Annual $ 97,000.00 5% 12.466 $ 1,210,000.00 Net Present Value $ 1,710,000.00 6.0 Evaluation DRSCW 6 -15 June 2009 DO Improvement Feasibility Study Salt Creek Salt Creek ■leisstwr Oxygen Addition Aftemative 4 in Oak Aleadows Dam and Orate Mill Dam Impoundments Oak Meadows Gol Omse dam Ofd Oak Brook dam �Fu lersbwg Hoods Darn (CiravP e.o. I 2 6.0 Evaluation I a b e A e $9 Net Present DO Compliance -- Fish �- Impact - -- ---- -- - --- - --�� - - -- - -- -- -- --- - - -- -- -- ------- --- - -- - --------------------------------------------- > $208,000,000 !r �-- ---------- - ---------------------------------------- ------ ------ ------ ---- -- ------- -- -- ------- ---- ------ Impoundment change -- ----------------- OM- $25011000 1 - J ----- - - - --- : ` I _ achieved in Fullersburg Woods proved P 4 O cti Ily I� v 1ia A� .-p ---- -- - - - - --- --- --------- -- U - -- p---- --- ---- --- ----- -- - - -- d DO Standard (above 5 mgfL at any tkiie)— �. -- ------------------------------------------- -------- ----- ---------- ----- -- --- - - - - -- 4y _ _ _ - r - - -- --- ------ -- --- ........... -- -- -- ---------------------------------------- 0 5o 45 40 35 25 20 t5 to 5 0 Distance kom downstream (tm) �DD[mg 1 _00(m90211.) Min DD(rn00210 Max - - 470 sat A Point S.. Figure 6-7. Oxygen Addition Alternative Minimum D.O. vs. Downstream Distance 6.6 Summary of Options Four options have been" evaluated to increase the dissolved oxygen at the lowest points on Salt Creek. For comparison purposes, the net present value of each alternative can be compared. Where there are no on -going operating costs, the net present value was set equal to the capital cost. Not all options will achieve the desired minimum DO of 5.0 mg/L in the June and July months. A summary of the net present values is as follows: Option Net Present DO Compliance Habitat Fish Value, $ Impact Passage 1- Eliminate Point > $208,000,000 Not in the Fullersburg Woods No No Source Pollutants Impoundment change 2 -Oak Meadows OM- $25011000 Likely achieved above OM, Im- Yes Dam Removal and GM- $800,000 to achieved in Fullersburg Woods proved Bridging/Partial $1,100,0W Impoundment. Not in Butter - breach at Graue Mill field Rd to Old Oak Brook Dam 3 -Air based In- OM41,19011000 OM -Yes (1 or 2 units) No No stream Aeration GM- $21050,000 GM -Yes. No- Butterfield Rd to Old Oak Brook Dam 4 -High purity OM411410,000 OM -Yes No No Oxygen Addition GM -$ 1,710,000 GM -Yes No- Butterfield to Old Oak Brook Dam DRSCW 6 -16 June 2009 DO Improvement Feasibility Study Salt Creek 6.0 Evaluation The low cost option at the Oak Meadows Dam is to remove this dam, which has a net present value of $250,000. The next lowest option is air based in- stream aeration assuming one installation will be sufficient to maintain the DO above 5.0 mg/L. At Graue Mill bridging or partial breaching of the dam is also the lowest cost option, with a net present value of between $800,000 and $1,100,000. High- purity oxygen is the second lowest cost option, with a net present value of $1,710,000, assuming that one system can maintain the DO above 5.0 mg/L adjacent to the dam. As discussed previously, complete dam removal has the advantage of improving the fish and benthic qualities upstream of the dam. Also, as discussed in Section 2.5.1, the Oak Meadows Darn is in need of repair, and there are on -going costs associated with maintaining this dam. If supplemental oxygen addition is selected, there are on -going operational costs that some entity will have to assume responsibility for as well as the on -going costs. This is more complicated than the dam removal/bridging/partial breach option, where the costs are all associated with the initial capital costs. Based on the recent dam removal projects within DuPage County, funding assistance from both the State and Federal Governments for the capital costs have been successfully secured. It is doubtful that for operating costs that such external funding sources will be available. Implementation will depend first on reaching consensus of the stakeholders. Given the location and condition of the Oak Meadows Dam, support for removal is expected to be strong among the stakeholders. Funding will be the key to implementation. DuPage County Division of Stormwater Management is currently managing two dam removal projects. It is recommended that these projects be completed so that the water quality benefits can measured and confirmed before proceeding with any of the recommended projects contained in this report. Graue Mill Dam has a significant historical component and local interest in preserving this dam is high. Several public outreach meetings have been held in the local community, and comments were received on the value of this dam to the community from a historical perspective and a perspective. These comments are summarized in Appendix C. It is clear from these meetings that building a consensus on how best to address the water quality issues while preserving the historical and aesthetic value of the dam/impoundment will require significant effort that will need to be expended before proceeding in any direction at this location. The comments concerning the documentation of impacts at the sites where dam removal is ongoing given in the paragraph above are equally applicable here. The de- watering gates at the site provide the possibility to draw water levels down the site and observe what habitat is available as well as gauge impacts on DO. The idea of using the structure was raised at both the DRSCW DO Committee and the public meetings. DRSCW 6 -17 June 2009 Meeting 1. 7.30 PM Oak Brook Village Hall. 03.18.2009. Number of attendees' 44 ; Comments: (Italicized are hosts answers) 4ti Public Comments y' Two solutions were proposed, the second was not clear. 1. Bridging or ramping 2. Partial Breach - water not over the top of the dam unless auxiliary pumping Will there be a concrete apron installed with the breaching option? There would be a natural scour pool. There would not be an apron installed, perhaps there would be buttressing of the dam. Scour pool is a bad term, it implies sediment in my backyard. Erosion cannot increase under the regulations. What was the cost of dredging when completed previously? $500,000-600, 000 in 1995 dollars Can aeration be created any other way? Bridging, riffles and artificial aeration Can riffles be used upstream of the dam? No, a change in elevation is needed, it can't be done in a flooded area What would the bridging option look like? The crest would go down, ramp created on the downstream side. Would there be water flowing over the dam? Yes, but part of the dam would have to be removed to achieve the DO standard, the fall would be smaller than at present What would it look like upstream in the bridging option? Look at diagram — pink shows where the water level would be if the crest was decreased by one foot. The aqua shows two feet. The yellow shows three feet. The channel will narrow with the bridging option. Committee member is disappointed with the context, the colors are bad, the slides are different, the committee met four times and they had not seen this graphic. Gates were put in at the dam to make it a flood control structure. When the gates are open the upstream channel recedes to 35 feet wide, can't see it from Spring Road. Vegetation will impede the flow of water when flooding. Under no circumstances will any part of this project make flooding worse. Trees slowing down flow more than offset by increased storage? Bath tub example. The reservoir will be empty. If the sediment decomposing take DO wont dredging help? Sediment is constantly being added and even a fine layer will trigger oxygen consumption. No re- aeration in pool. Treatment plants add sediment at storm time. Treatment plants have constant flows. If we do activity and do not meet the DO goal, IEPA will come back and say do more, this is not an attempt to draw attention away from POTWs There was a request for three dimensional models. That would be cost prohibitive and would not add to the understanding of the problems or potential solutions. How does the mill race continue to flow if the dam is taken down three feet? If the dewatering gates are open the raceway is dry. There are a number of ways to accomplish this, how it will be accomplished exactly hasn't been decided. Should be discussed with mill operators. It can, and should be, engineered to continue to flow. Are there any threatened or endangered species at the site? If there are no threatened and endangered species, it's not that critical of a problem. No, there have not been any threatened or endangered species identified on site because the habitat and water chemistry are so degraded that they can not support threatened or endangered species. The habitat will not support even common species. A microphone should be on hand. There will be one at the March 31St meeting. Concerned because the character of the mill area will be changed, lose the beauty of the area — artists, photographers, families come. There are 20,000 visitors a year. This is the only place where we have a historic dam that dates back to the 1830s. The Clean Water Act does not allow for exemptions, we are looking for a balance between the history and water quality improvements. How can the historic integrity of the site be maintained if water does not flow over the dam? Where is EPA? What can we do? Who do we contact beyond this meeting? (EPA's solution is to go to treatment plants, but that costs money and won't meet the stated environmental goals. We would still have impairment on the waterway even under optimal plant upgrades. We have two options, dam modification and aeration. We discarded aeration because it doesn't solve the habitat problems and it is expensive. Aeration scenarios were examined, four different options that resulted in the following 1) very expensive equipment 2) costly maintenance 3) no one to maintain and operate 4) where to locate the equipment. If ever treatment plant puts out drinking water quality effluent, the problem is not solved. What about the two bridges above the dam? It was clarified that the question was referring to additional dams shown above Graue Mill. Oak Meadows is owned by the Forest Preserve District and will be addressed — likely removed. The Old Oak Brook Dam is not causing a major problem. We have taken the worst problem on the waterway and made it a priority project. Then we will monitor to see if the problem is solved. Are we going to destroy Graue Mill so we can take of one mile of Salt Creek? All indicators show that area at Graue Mill is one of the largest water quality problems on Salt Creek. I live downstream, what will happen to the water? There's quite a bit of flooding now. The dam creates no storage so both options will cause no increase in flooding. The DuPage County Ordinance does not allow for an increase in flooding. Do dewatering gates exist at the dam? Yes. Can we open the bridge and see if it improves DO? It was noted that the question refers to the dewatering gates, not a bridge. The Forest Preserve District operates the gates and has said that they are insufficient to dewater the impoundment. They clog with woody debris. The Forest Preserve District does not want to routinely clean the gates. The dewatering gates have approximately half the capacity of what is being proposed. Option should be examined more closely and had come up at the DRSCW working committee on DO Both options for altering Graue Mill dam will not preserve the historical aspect. The aesethics will be destroyed. Wedding parties are there every weekend. Painters paint the waterfall. The water flowing over the dam is an aeration system. He's appalled that we have a government that is worried about marginal affects. To us, and a number of other groups such issues are not small but essential. Environmental agencies will sue if the solutions do not have enough of an environmental effect. Commentor has been on the Salt Creek Committee. She was the Vice Chair of the DuPage County Stormwater Commission. She was around for the flood of 1987. The DuPage County Stormwater Committee is the only one licensed by the Corps of Engineers to operate on their behalf. They would lose that if they allowed flooding to be exacerbated downstream. It's important for residents to negotiate out a good answer. IEPA answers to USEPA, they hold all the cards. We need to collaborate to come up with a reasonable solution. In Person Comments If water flow in raceway can be maintained project look like fair compromises Presenter knows nothing of history and is biased It is understands that area upstream is essentially dead (devoid of life) Previous skepticism of project largely assuaged Very interesting presentation Maintaining flow in race way is key Comment Box: Fishable /swimmable? It won't help to alienate the sediment problems or remove the dams if the dumping of raw sewage continues in Fullersburg Woods from the Hinsdale Sanitary Sewers (Flagg Creek POTW). Meeting 2. 7.30 PM Oak Brook Village Hall. 03.31.2009. Number of attendees � 60 f„ Comments: Speaker from the' Du"llersburg Homeowners Association 550 homes, personal observations. Moved here with wife 58 years ago. His home was built in 1874, one of the only structures here that is that old including the dam, the York grocery store. He thinks this is heritage vs. fish. He doesn't know where the swimming concept came //from. He is an environmentalist, but you have to draw the line somewhere. Oakbrook is the jewel of DuPage County. It has eight historical buildings. He doesn't know the distinction between a creek or a river. The creek is an essential part of the character of Oakbrook. The vegetation will grow up and encroach and the creek will disappear visually. Are we here to support the fish downstream? Solution is to reexamine dredging in phases and discovery. There is no doubt that we could get grants. If dredging doesn't meet the criteria perhaps breaching. He wants to start group. Has to be a compromise. Last report said Salt Creek meets the DO standard and he thought DO problem was from Addison Creek. Certainly wouldn't want this to wind up in litigation, but don't rule it out. What body has ultimate authority? Who would do project This is convoluted in Illinois. Property lines go out to the middle of Salt Creek in Elmhurst and would have to get property rights. IEPA is responsible for water quality. IDNR is responsible for fish and animals. In this case there is one property owner — the Forest Preserve District, project can not happen without their consent. What will happen is that the Workgroup will do the data collection, hire a design consultant through grants, hand over the project to DuPage County Stormwater because they have the resources and knowledge to implement the project. What is the authority of the Village of Oak Brook? Answer by Village Trustee - the Village has no authority. If the residents say that don't want any change the Village can make a formal statement to the Forest Preserve District, the Workgroup, the IEPA. Wouldn't the work require a construction permit from the Village because it's within the Village limits? Not aware of how permitting would function What agency is requiring the Forest Preserve District to do this? IEPA is requiring water quality improvements. The best way to advance to those improvements is to reduce the size of the impoundment. Last meeting, it was indicated another dam upstream of Graue Mill would be removed or breached. Wouldn't it be prudent to do that first? We are trying to get the biggest bang for our buck. We are discussing removing the dam at Oak Meadows with Forest Preserve District. Old Oak Brook dam is not that big of a DO problem because it has a small impoundment. i What about flooding, salt, parking lot runoff? NPDES Phase 11 addresses stormwater. The program is in its 6th year. It changes how stormwater is treated. Silt fence, grassy swales, are Best Management Practices (BMPs), which are required to be implemented in communities to treat stormwater runoff. Stormwater is the second biggest problem in Salt Creek. The Workgroup has been very active in chloride education and is also looking at stormwater. Russ Strand from Robin Hood Ranch: Report says Salt Creek is an effluent dominated stream, what does that mean? Salt Creek is dominated, approximately 85 %, by wastewater effluent at low flow conditions, (when it's not raining). This starts at the Eagen plant in Schaumburg and goes all the way to Elmhurst. What is a combined sewer overflow (CSO)? Every community has a sewer collection system. A CSO is storm and sanitary sewers in one system. Elmhurst and Oak Brook have separate sanitary sewers which go to the treatment plant. The storm sewer goes directly to the river. In a CSO, all flow goes to the plant and is fully treated for up to the 10 year storm event. For the 10 year storm event and above, the flow bypasses part of the treatment plant, after it is treated through gravity and separation. A 10 year event or greater is very diluted. What is a sanitary sewer overflow (SSO)? Flagg Creek POTW example An SSO should never happen, it's a violation of the Clean Water Act. It happens when the sanitary collection system is overwhelmed. It consists of very diluted material, but it is illegal. He has picked up material in Fullersburg Woods. Syringes, etc. This information was shared with the Forest Preserve District and Flagg Creek Sanitary District after the last meeting. It could be many things, such as a sewer blockage or collapse. He'd like to see these things fixed before we talk about taking out the dam. Agreed Do you have any flexibility or judgment in this issue? The fact that you want to turn this into a swamp is offensive to me. Why are we returning this is the mosquitoes? You used models, the global warming model from 20 years ago are wrong. Models can say whatever you want them to say. The Clean Water Act does not have exemptions. Our flexibility is how we can implement these things. We've thought about merging what was done at the Kent dam with breaching, that was a flexible approach. On mosquitoes the situation is quite the reverse, mosquitoes love low DO and still water — the impoundment is more desirable than a moving river. Also in free flowing conditions more fish are available to consume mosquito larvae. Yes models can say what you want it to say. They have alos proven powerful tools for predicting events. On top of the model, we have three years of continuous DO monitoring. All other parameters were directly sampled — habitat, fish, macro invertebrates. Once again the goal is water quality not a certain action. How much does the impoundment have to be reduced by to meet minimum DO standard? Look at the display boards in the back of the room. This is the kind of flexibility we have — if we reduce the hydraulic head of the dam by 2.5 feet, the river will draw down by 3 feet, not sure what the area of the impoundment would be, but this would meet the DO standard. Can residents participate in the committee? Tom Richardson said that he is a resident of Oak Brook and a member of the committee, as wells Joe Rush from the Fullersburg Woods Association, Karen Bushy from Graue Mill, and another Oak Brook resident. So far the Workgroup has confirmed that there is a water quality problem. We're not rushing to provide any solutions, there is much more time for community input. Has there been any consideration of the change in property values? Where the bridge goes over the creek, the creek is 90 feet wide and will be reduced to 20 -40 feet. The creek is hard to see. Vegetation and trees will further hide it. The Forest Preserve District will be a major partner and they will have to look at the management plan. Will provide information on property values Everyone keeps saying this is not a dam issue, it is a dam issue. The dam has been there since the 1850's. The perspective given is always from the south side of the creek looking away from the mill, the mill would sit without any water around it and would look very unnatural. This is human habitat and we need to look at the human side of the story. Partial removal will destroy what the dam is. The mill was a site on the underground railroad. The dam was built to control water, to regulate flow. If you open up the dam, how will you control erosion down stream? The dam was not built for flood control or erosion control. Flood levels and erosion cannot change under the current permitting system. The dam was built as a hydraulic battery. It was said before that the dewatering gates were not enough, that 60 feet of the dam would have to be removed and that the dewatering gates are only 25 -30 feet. We don't need an all or nothing approach. We should strategically place a bunch of rocks upstream ad open the gates from Monday through Thursday. Close the gates for the weekend. This maybe done as a demonstration and to gather further data. In the long term, it is not feasible because the capacity is not there and the Forest Preserve District does not want to clean the dewatering gates frequently. The Forest Preserve District works for the taxpayers. What about the ducks, geese and the one heron? The habitat will bring more birds. We currently have puddle ducks. There will be more herons because they are fishermen. If the stream is effluent dominated, what are our native fish species? 16th and Spring Road is the location of the first native flow. Upstream of that it was stormwater. The Des Plaines has always had a constant flow. The fish migrated upstream. Did you do BOD measurements with normal flow. No. 26 villages are contributing (to the Workgroup), what is the total amount of the bill (for the Salt Creek DO study)? $300, 000 for all the studies on Salt Creek. Proposal to dredge and let the creek go down, open the flood gates and when the sludge dries out use front loaders to put it on Forest Preserve District land. Dredge down to clay. It will be cheaper. A million dollars will be used, there are lots of millionaires in this room, about half. We're not talking about that much money. My understanding is that the mill would be shut down part of the time, and the wheel would only turn part of the time. When I come under the bridge in my costume it's like Brigadoon. Kids do change in their heads. It's a wonderful place for schools; they come to Robert Crowne and Graue Mill. Those who work there love it. The wheel will turn under all scenarios. Comment Box: This is a public issue. Water quality affects everyone. Oak Brook residents' views of the creek as it is now are not a concern. It's not just fish — it's also habitat. All over the U.S. dam removal is occurring — in every case all aspects of the water are improving. Oak Brook Village has no legal authority over the removal or change in the dam,. As a fisherman I would like to see the dam come out and fish extend their range upstream