East Branch DuPage River Watershed & Resiliency Plan (DRAFT)
Prepare, React and Recover February 2015
y eg He at a tr lth S & & W ip e h l s lb r e e i d n a g e L
I n
f r a s t y r t u e c i t c u o r e S
& & E y nv om iro on nm Ec ent
Prepared For DuPage County Stormwater Management
By:
Hey and Associates, Inc. Birchline Planning, LLC. Camiros, Ltd. Contents
1. Executive Summary ...... 1
2. Glossary ...... 2
2.1. Agencies/Stakeholders ...... 2
2.2. Acts/Ordinances/Programs ...... 4
2.3. Terms ...... 5
2.4. Watersheds, Subwatersheds and River Reaches...... 7
3. Introduction ...... 9
3.1. Watershed Planning Overview ...... 9
3.1.1. What is Watershed Planning? ...... 9 3.1.2. Watershed Planning for the East Branch DuPage River ...... 10 3.1.3. Resilience and Watershed Planning ...... 11 3.1.4. Addressing Unmet Needs in the East Branch DuPage River Watershed ...... 12 3.1.5. Statement of Plan Goals ...... 12 3.2. Watershed Planning Process & Data Collection ...... 14
3.2.1. Identifying Watershed Jurisdictions and Stakeholders ...... 14 3.2.2. Stakeholder Data Collection Process ...... 18 3.3. Watershed Physical and Water Quality Data ...... 18
3.3.1. Flooding-Related Data & Analysis ...... 19 3.3.2. Demographics & Socioeconomic Data ...... 19 3.4. Public Outreach & Stakeholder Engagement ...... 19
3.5. Plan Adoption ...... 21
4. Watershed Characteristics Assessment ...... 22
4.1. The East Branch DuPage River Watershed ...... 22
4.1.1. Mainstem of the East Branch DuPage River ...... 23 4.1.2. East Branch Subwatersheds ...... 23
i
4.1.3. Channel Conditions ...... 26 4.2. Climate and Precipitation ...... 27
4.2.1. Climate ...... 27 4.2.2. Precipitation...... 27 4.3. Geology and Topography ...... 28
4.4. Soils ...... 29
4.4.1. Soil Series ...... 29 4.4.2. Hydric Soils ...... 32 4.4.3. Soil Erodibility ...... 32 4.4.4. Soil Infiltration Capacities (Hydrologic Soil Groups)...... 33 4.5. Cultural Resources ...... 35
4.6. Natural Resources ...... 36
4.6.1. Illinois Natural Area Inventory Sites ...... 36 4.6.2. Parks, Forest Preserve Lands and Trails ...... 37 4.6.3. Threatened and Endangered Species ...... 38 4.6.4. Wetlands, Riparian Areas, and Potential Wetland Restoration Sites ...... 39 4.7. Groundwater Resources ...... 42
4.8. Agricultural Best Management Practices ...... 43
4.9. Watershed Drainage, Hydrology & Hydraulics ...... 44
4.9.1. Stream Flow, Discharge & Baseflow Characteristics ...... 44 4.9.2. Channel Conditions ...... 45 4.9.3. Hydraulic Structures ...... 46 4.9.4. Stormwater Management Facilities ...... 48 4.10. Floodplains ...... 50
4.11. Water Quality ...... 51
4.11.1. State of Illinois Water Quality Reporting ...... 52 4.11.2. IEPA Permit Programs ...... 55 4.11.3. Water Quality Monitoring Stations, Results and Trends ...... 58 4.11.4. Nonpoint Pollution Sources & Load Analysis ...... 66
ii
4.12. Critical Areas for Watershed Improvement ...... 67
4.12.1. Critical Subbasins ...... 67 4.12.2. Critical Stream Reaches ...... 67 4.12.3. Summary and Conclusions ...... 67 5. Land Use, Demographics and Transportation ...... 68
5.1. Watershed Land Use and Land Cover ...... 68
5.1.1. Historical Land Use ...... 68 5.1.2. Current Land Use and Land Cover ...... 69 5.1.3. Future Land Use / Land Cover Projections ...... 70 5.1.4. Land Use Impacts on the East Branch Watershed ...... 71 5.1.5. Impervious Area Analysis ...... 72 5.2. Watershed Socioeconomic and Demographic Conditions ...... 72
5.2.1. Population ...... 73 5.2.2. Income Profile & Low-Moderate Income Areas ...... 75 5.2.3. Economic Activity & Industry Profile ...... 77 5.2.4. Housing & Home Ownership ...... 78 5.2.5. Community Facilities ...... 81 5.2.6. Community & Organizational Resources ...... 82 5.3. Transportation ...... 82
5.3.1. Existing Transportation Network & Issues ...... 83 5.3.2. Proposed Transportation Projects ...... 85 6. Watershed Problems & Opportunities ...... 86
6.1. Water Quality Problems and Opportunities ...... 86
6.2. Flooding and Flood Resilience Issues ...... 86
6.2.1. Types of Flooding and Flood Damages in the Watershed ...... 86 6.2.2. Urban and Nuisance Flooding ...... 88 6.2.3. Description of Major Flood-Affected Areas ...... 89 6.2.4. Problem Areas Identified by Watershed Stakeholders ...... 92 6.2.5. Health and Wellbeing Impacts ...... 93 6.3. Land Use Plans, Policies & Practices ...... 99 iii
6.3.1. DuPage County Countywide Stormwater and Flood Plain Ordinance (DCCSFPO) 99 6.3.2. Municipal Plans & Initiatives...... 103 6.3.3. Planning for Natural Areas ...... 103 6.4. Watershed Jurisdictional Coordination ...... 109
6.4.1. Roles and Responsibilities ...... 109 6.4.2. Policies and Regulations ...... 109 7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives...... 111
7.1. Existing Studies and Analyses ...... 111
7.1.1. FEMA Flood Insurance Study (FIS) ...... 111 7.1.2. East Branch Mapping Updates ...... 112 7.1.3. East Branch – River-Dumoulin Area ...... 113 7.1.4. East Branch – Valley View Area ...... 114 7.1.5. Illinois Route 53 North ...... 114 7.1.6. Other Local Studies ...... 115 7.2. Economic Analysis ...... 115
7.3. Recommended Alternatives ...... 115
8. Watershed Needs and Issues ...... 117
8.1. Watershed Resilience Principles & Goals...... 117
8.2. Identification of Unmet Needs ...... 120
8.2.1. Housing ...... 120 8.2.2. Infrastructure ...... 122 8.2.3. Impacts to Environmental Health ...... 126 8.2.4. Economic Impacts ...... 126 8.3. Most Impacted / Most Distressed Area...... 127
8.4. Additional Flood Impacted and Distressed Areas ...... 127
8.5. Critical Areas of Environmental Degradation ...... 128
9. Recommended Action Plan ...... 129
iv
9.1. Watershedwide Programmatic Plans ...... 129
9.1.1. Infrastructure ...... 129 9.1.2. Housing ...... 132 9.1.3. Environmental Health ...... 134 9.1.4. Policy, Finance and Regulatory Tools...... 135 9.1.5. Social Cohesion ...... 136 9.1.6. Leveraging ...... 137 9.2. Site Specific Flood Risk Reduction Plans ...... 138
9.2.1. Most Impacted / Most Distressed – River Dumoulin Area ...... 138 9.2.2. Local Projects ...... 140 9.2.3. Reserved ...... 145 9.3. Non-Point Source Pollution Control Plan ...... 145
9.3.1. Non-Point Source Reduction Programmatic Action Plan ...... 146 9.3.2. Non-Point Source Reduction Site Specific Plans ...... 157 9.3.3. Non-Point Source Reduction Education and Outreach Plan ...... 158 10. Plan Implementation & Evaluation ...... 159
10.1. Implementation Process ...... 159
10.2. Stakeholder Engagement ...... 159
10.3. Implementation Roles & Responsibilities ...... 159
10.3.1. Conservation Strategies ...... 159 10.3.2. Jurisdictional Strategies ...... 159 10.3.3. Other Stakeholder Strategies ...... 160 10.4. Implementation Schedule ...... 160
10.5. Funding Sources ...... 160
10.6. Interim Milestones & Progress Evaluations ...... 160
10.7. Hydrologic ...... 160
10.8. Data Collection & Analysis ...... 160
10.9. Flood Forecasting & Watershed Resilience ...... 161
v
11. References ...... 162
12. Exhibits ...... 163
13. Appendices ...... 164
13.1. Appendix A: Stakeholder Questionnaires ...... 165
13.2. Appendix B: Other East Branch DuPage River Studies ...... 166
13.3. Appendix C: Watershed Jurisdictions ...... 167
Figures
1-1 Watershed Diagram
4-1 Example Soil Profile
5-1 Percentage of Housing Units Constructed by Decade
5-2 Distribution of Value of Owner Occupied Housing Units
5-3 Traffic Effects of Road Closures Tables
3-1 Municipal Jurisdictions within the East Branch DuPage River Watershed
3-2 Non-Geographic Stakeholders & County Departments
3-3 Public Sector Stakeholders and Areas of Responsibility
4-1 Drainage Areas of the East Branch
4-2 East Branch Mainstem and Subwatershed Information
4-3 Soil Series in the East Branch DuPage River Watershed (DuPage County portion)
4-4 Percent Coverage of hydric and non-hydric soils in the East Branch
4-5 Highly erodible soils in the East Branch DuPage River Watershed
vi
4-6 Hydrologic Soil Groups and corresponding attributes in the East Branch DuPage River Watershed (DuPage County portion)
4-7 Hydrologic Soil Groups including acreage and percent of watershed
4-8 National Register of Historic Places sites in the East Branch watershed
4-9 INAI Sites located within East Branch DuPage River watershed
4-10 Natural Areas and Recreational Parks in the East Branch DuPage River watershed
4-11 Historic and Existing Wetland Area, East Branch Watershed and DuPage County
4-12 Active and historic stream gauges in the East Branch DuPage River watershed
4-13 Historic Low and Mean Flows in the East Branch DuPage River watershed
4-14 Dams in the East Branch watershed
4-15 Major Culverts in the East Branch watershed
4-16 Open Water Areas of the Compensatory Storage Facilities within the East Branch watershed
4-17 Categorization of 303(d) Listed Waters in Illinois
4-18 2014 303(d) Listings in the East Branch watershed
4-20 Approved TMDLs in the East Branch watershed
4-21 Wastewater Treatment Plants (WWTPs) and NPDES Industrial Discharges in the East Branch watershed
4-22 Illinois DO Water Quality Standard
4-23 AWQMN Monitoring Stations in the East Branch DuPage River Watershed
4-24 Water Quality Studies Conducted by the DRSCW
4-25 Sierra Club Sampling Sites in the East Branch DuPage River watershed
5-1 United States Geological Survey (USGS) GIRAS Land Use and Land Cover for the East Branch Watershed (DuPage County Portion)
5-2 CMAP Existing Land Use for the East Branch Watershed
5-3 Projected Land Use for the East Branch Watershed
5-4 Total Impervious Cover by Land Use/Land Cover Type (2010)
5-5 2013 Population and Household Structure vii
5-6 Educational Attainment and Language
5-7 Household Income Distribution (Household Income in the past 12 Months in Current 2013 Dollars)
5-8 Employment and Disability Status
5-9 FY2014 Income Limits for Low, Very Low & Extremely Low Income Households
5-10 2013 and Projected 2016 Jobs by Industry, DuPage County
5-11 Housing Tenure, Values and Characteristics
5-12 Age of Housing Structures
5-13 Value of Owner-Occupied Housing Units, Median Value, Median Rent & Substandard Status
5-14 Community Organizations and Resources
5-15 Transportation Related Pollutants
6-1 Problem Areas Identified by Stakeholders
7-1 Summary of FIS Data Sources for Hydrologic and Hydraulic Analyses per the 2007 FIS
8-1 DuPage County Residential Ownership Unmet Needs – Damage at least $8,000
8-2 DuPage County Residential Ownership Unmet Needs – Flooding Over Four Feet
8-3 Infrastructure Needs Exhibits
Exhibit 1 Overview of Watershed
Exhibit 2 Jurisdictions
Exhibit 3 Transportation Network
Exhibit 4 East Branch DuPage River Subwatersheds
Exhibit 5 DuPage County 2-foot Topography
Exhibit 6 Soil Series in the East Branch DuPage River Watershed
Exhibit 7 Coverage of Hydric Soils in the East Branch DuPage River Watershed
viii
Exhibit 8 Highly Erodible Soils in the East Branch DuPage River Watershed
Exhibit 9 Hydrologic Soil Groups in the East Branch DuPage River Watershed
Exhibit 10 Historic Places/Districts in the East Branch DuPage River Watershed
Exhibit 11 Forest Preserves in the East Branch DuPage River Watershed
Exhibit 12 Wetlands in the East Branch DuPage River Watershed
Exhibit 13 100-year Floodplains
Exhibit 14 NPDES Point Source Discharges
Exhibit 15 Sampling Sites
Exhibit 16 Existing Land Use in the East Branch DuPage River Watershed
Exhibit 17 Future Land Use in the East Branch DuPage River Watershed
Exhibit 18 Low to Moderate Income Census Tracts
Exhibit 19 Critical Facilities in the East Branch DuPage River Watershed
Exhibit 20 Heat Map of Damages from April 2013 Flood Event
Exhibit 21 Road Construction, Repairs, or Reconfigurations (Ongoing or Proposed, 2015- 2020) for Roads in the East Branch DuPage River Watershed
Exhibit 22 Identified Flood Problem Areas
ix
1. Executive Summary A formal executive summary will be prepared during and after the comment period.
What is a Watershed?
Everyone in DuPage County lives in a watershed or area of land that drains water to a stream or lake. Although the definition is simple, the interaction is complex between natural elements such as climate, surface water, groundwater, vegetation, wildlife and humans. It is these human influences that can have the biggest impact by producing polluted stormwater runoff, increased impervious surfaces, altering stormwater flows and increased erosion.
Why a watershed plan?
A watershed plan will help describe:
1. Impairment
2. Flooding
3. Unmet needs
4. Resilience features
Figure 1-1: Watershed Diagram It will also help identify:
1. Actions
2. Flood resilience actions for Most Impacted/Most Distressed and other Impacted/Distressed areas
3. Structural & non-structural water quality improvements
4. Opportunities for implementation of green infrastructure
5. Improved Flood Forecasting
1
2. Glossary 2.1. Agencies/Stakeholders Burlington Northern Santa Fe (BNSF) Railroad: http://metrarail.com/metra/en/home/maps_schedules/metra_system_map/bnsf/schedule.ht ml
Chicago Metropolitan Association of Planning (CMAP): http://www.cmap.illinois.gov/
Chicago Region Trees Initiative (CRTI): http://www.mortonarb.org/science- conservation/chicago-region-trees-initiative
Chicago Wilderness (CW): http://www.chicagowilderness.org/
City of Wheaton (CW): http://www.wheaton.il.us/
Corporate and Business Landowners (CBL)
Developers & Builders (DB)
Downtown Wheaton Association (DWA): http://downtownwheaton.com/
Drainage Districts (DD)
DuPage County Community Foundation (DCCF): http://www.dcfdn.org/
DuPage County Division of Transportation (DuDOT): http://www.dupageco.org/DOT/
DuPage County Health Department (DCHD): http://www.dupagehealth.org/
DuPage County Stormwater Management Plan (DCSMP)
DuPage County Stormwater Management Planning Committee (DCSWM or DCSWMPC): http://www.dupageco.org/swm/
DuPage County Watershed Steering Committee (DCWSC)
DuPage River Salt Creek Workgroup (DRSCW): http://www.drscw.org/
Educational Institutions (EI)
Federal Emergency Management Agency (FEMA): http://www.fema.gov/
Federal Highway Administration (FHWA): http://www.fhwa.dot.gov/
Forest Preserve District of DuPage County (FPDDC): http://www.dupageforest.org/
Forest Preserve District of Kane County (FPDKC): http://www.kaneforest.com/
2
2. Glossary
Golf Courses (GC)
Historic Architectural Resources Geographic Information System (HARGIS): http://gis.hpa.state.il.us/hargis/
Illinois Department of Natural Resources (IDNR): http://www.dnr.illinois.gov/
Illinois Department of Natural Resources Office of Water Resources (IDNR/OWR): http://www.dnr.illinois.gov/WaterResources/Pages/default.aspx
Illinois Department of Transportation (IDOT): http://www.idot.illinois.gov/
Illinois Emergency Management Agency (IEMA): http://www.illinois.gov/iema/Pages/default.aspx
Illinois Environmental Protection Agency (IEPA): http://www.epa.illinois.gov/index
Illinois Historical Preservation Agency (IHPA): http://www.illinois.gov/ihpa/Pages/default.aspx
Illinois Natural Areas Inventory (INAI): http://wwx.inhs.illinois.edu/research/inai/
Illinois State Geological Survey (ISGS): https://www.isgs.illinois.edu/
Illinois State Tollway Highway Authority (ISTHA): http://www.illinoistollway.com/homepage
Kane County Division of Transportation (KCDOT): http://www.co.kane.il.us/dot/
Kane-DuPage Soil and Water Conservation Districts (SWCD): http://www.kanedupageswcd.org/
Kishwaukee River Ecosystem Partnership (KREP): http://krep.bios.niu.edu/
Metropolitan Water Reclamation District of Greater Chicago (MWRD or MWRDGC): https://www.mwrd.org/irj/portal/anonymous/Home
Municipalities (all departments) (MUN)
National Technical Committee for Hydric Soils (NTCHS): http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/hydric/?cid=nrcs142p2_053963
National Wetlands Inventory (NWI): http://www.fws.gov/wetlands/
Natural Resources Conservation Service (NRCS): http://www.nrcs.usda.gov/wps/portal/nrcs/site/national/home/
Northeastern Illinois Planning Commission (NIPC), formerly NIPC, now part of CMAP
Northwestern Indiana Regional Planning Commission (NIRPC): http://www.nirpc.org/
3
2. Glossary
Parks Districts (PD)
Residents and Owners (RO)
School and Community Assistance for Recycling and Composting Education (SCARCE): http://www.scarceecoed.org/
Southeastern Wisconsin Regional Planning Agency (SEWRPC): http://www.sewrpc.org/SEWRPC.htm
The Conservation Foundation (TCF): http://www.theconservationfoundation.org/
Townships (TOWN)
Union Pacific West (UP-W) Railroad: http://metrarail.com/content/metra/en/home/maps_schedules/metra_system_map/up- w/map.html
United States Army Corps of Engineers (USACE): http://www.usace.army.mil/
United States Department of Agriculture (USDA): http://www.usda.gov/wps/portal/usda/usdahome
United States Department of Housing and Urban Development (HUD): http://portal.hud.gov/hudportal/HUD
United States Environmental Protection Agency (USEPA): http://www.epa.gov/
United States Fish and Wildlife Service (USFWS): http://www.fws.gov/
United States Geological Survey (USGS): http://www.usgs.gov/
2.2. Acts/Ordinances/Programs Community Development Block Grant Disaster Recovery Program (CDBG-DR): https://www.hudexchange.info/cdbg-dr/
Conservation Reserve Program (CRP): http://www.fsa.usda.gov/FSA/webapp?area=home&subject=copr&topic=crp
Conservation Reserve Enhancement Program (CREP): http://www.creppa.org/
DuPage County Countywide Stormwater and Flood Plain Ordinance (DCCSFPO): http://www.dupageco.org/EDP/Stormwater_Management/Regulatory_Services/1420/
Environmental Quality Incentives Program (EQIP): http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/financial/eqip/
4
2. Glossary
Grasslands Reserve Program (GRP): http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/easements/grassland/
Hazard Mitigation Grant Program (HMGP): https://www.fema.gov/hazard-mitigation-grant- program
Illinois Disaster Assistance Program (IDAP): http://www.dhs.state.il.us/page.aspx?item=47579
Illinois Groundwater Protection Act (IGPA)
National Flood Insurance Program (NFIP): https://www.fema.gov/national-flood-insurance- program
National Pollutant Discharge Elimination System (NPDES): http://www.epa.gov/region6/water/npdes/index.htm
Wetlands Reserve Program (WRP): http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/easements/wetlands/
Wildlife Habitat Incentive Program (WHIP): http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/financial/whip/
2.3. Terms Advance Identification of Disposal Areas (ADID)
Best Management Practice (BMP)
Carbonaceous Oxygen Demand (CBOD)
Combined Sewer Overflow (CSO)
Cubic feet per second (CFS)
Dissolved Oxygen (DO)
DuPage County Damages Model (DEC-2)
East Branch DuPage River (East Branch)
East Branch DuPage River Watershed and Resiliency Plan (Plan)
Flood Hydrograph Package (HEC-1)
Flood Insurance Rate Map (FIRM)
Flood Insurance Study (FIS)
Freedom of Information Request (FOIA) 5
2. Glossary
Full Equations (FEQ) Model
General Permit (GP)
Geographic Information Retrieval and Analysis System (GIRAS)
Geographic Information Systems (GIS)
Green Infrastructure Vision (GIV)
Gross Domestic Product (GDP)
High Impact-High Distressed (HIHD)
Hydrologic Engineering Center (HEC)
Hydrologic Soil Group (HSG)
Hydrological Simulation Program – Fortran (HSPF)
Illicit Discharge Detection and Elimination (IDDE)
Incident of Non-compliance (ION)
Metropolitan Planning Organization (MPO)
Million gallons per day (MGD)
Most Impacted-Most Distressed (MIMD)
Municipal Separate Storm Sewer System (MS4)
Notice of Intent (NOI)
Notice of Termination (NOT)
Peak-to-Volume Statistics (PVSTATS)
Plan (See East Branch DuPage River Watershed and Resiliency Plan)
Post-Construction Best Management Practices (PCBMP)
Public Service Announcement (PSA)
Quality Assurance/Quality Control (QA/QC)
Quality Review 3 (QR3)
Regional Permits (RP)
Resource Protection Area (RPA) 6
2. Glossary
Sensitive Aquifer Recharge Areas (SARAs)
Soil Erosion and Sediment Control (SESC)
Stormwater Pollution Prevent Plan (SWPPP)
Threatened and Endangered (T&E)
Total Maximum Daily Load (TMDL)
Total Suspended Solids (TSS)
Wastewater Treatment Plant (WWTP)
Water Surface Profiles Program (HEC-2)
2.4. Watersheds, Subwatersheds and River Reaches 22nd Street (EBTS)
Armitage Creek (EBAR)
Army Trail Road Tributary (EBAT)
Crabtree Creek (EBCR)
East Branch DuPage River Mainstem (EBEB)
Glen Park (EBGP)
Glencrest Creek (EBGL)
Lacey Creek (EBLA)
Prentiss Creek (EBPR)
Rott Creek (EBRC)
St. Joseph’s Creek (EBSJ)
Swift Meadows (EBSM)
Tributary No. 1 (EBE1)
Tributary No. 2 (EBE2)
Tributary No. 3 (EBE3)
Tributary No. 6 (EBE6)
7
2. Glossary
Tributary No. 7 (EBE7)
Willoway Brook (EBWI)
8
3. Introduction 3.1. Watershed Planning Overview 3.1.1. What is Watershed Planning? A watershed plan brings together assessment and management information for a geographically defined watershed of a particular water body – in this case, the watershed of the East Branch DuPage River (Exhibit 1, Overview of Watershed) – into a plan for the protection, enhancement and monitoring of the water body and its associated watershed. The Plan for the East Branch watershed, which drains all or parts of What’s in a Watershed Plan? Bloomingdale, Carol Stream, Glendale
In March 2008, the United States Environmental Protection Heights, Lombard, Addison, Glen Ellyn, Agency (USEPA) published a Handbook for Developing Wheaton, Warrenville, Naperville, Oak Watershed Plans to Restore and Protect Our Waters (EPA Brook, Downers Grove, Lisle, Westmont, 841-B-08-002) for the development and implementation of plans that help to restore and protect water quality. USEPA Woodridge, Naperville, Darien, Bolingbrook requires that nine elements be addressed in watershed plans and portions of unincorporated DuPage funded with incremental Clean Water Act §319 funds, and County, compiles essential data and strongly recommends that they be included in all other watershed plans intended to address water quality analysis, along with identification of impairments. The nine elements of watershed plans, which are stakeholders, resources and actions, that incorporated into this Plan, include: will be needed to develop and implement the 1. Identification of causes of impairment and pollutant Plan’s goals over time. sources or groups of similar sources that need to be controlled to achieve needed load reductions, and any other goals identified in the watershed plan. Sources that Since the late 1980s, watershed need to be controlled should be identified at the organizations, tribes, and federal and state significant subcategory level along with estimates of the extent to which they are present in the watershed. agencies throughout the United States have 2. An estimate of the load reductions expected from management measures. moved toward managing water quality 3. A description of the nonpoint source management through a watershed approach (see sidebar measures that will need to be implemented to achieve load reductions and a description of the critical at left). A watershed approach is a flexible areas in which those measures will be needed to framework for managing water resource implement this plan. 4. Estimate of the amounts of technical and financial quality and quantity within specified assistance needed, associated costs, and/or the drainage areas, or watersheds. This sources and authorities that will be relied upon to implement this plan. approach includes stakeholder involvement 5. An information and education component used to enhance public understanding of the project and and management actions supported by encourage their early and continued participation in sound science and appropriate technology, selecting, designing, and implementing the nonpoint source management measures that will be implemented. and requires a certain level of technical 6. Schedule for implementing the nonpoint source expertise and the participation of a variety of management measures identified in this plan that is reasonably expeditious. people with diverse skills and knowledge. 7. A description of interim measureable milestones for The watershed planning process works determining whether nonpoint source management measures or other control actions are being implemented. within this framework by using a series of 8. A set of criteria that can be used to determine whether loading reductions are being achieved cooperative, iterative steps to characterize over time and substantial progress is being made toward existing conditions, identify and prioritize attaining water quality standards. 9. A monitoring component to evaluate the effectiveness problems, define management objectives, of the implementation efforts over time, measured against develop protection or remediation the criteria established. strategies, and implement and adapt 9
3. Introduction selected actions, as necessary. The outcomes of this process are documented or referenced in the watershed plan. Watershed plans also then identify the parties responsible for implementation actions and the potential funding sources.
3.1.2. Watershed Planning for the East Branch DuPage River Historically, precipitation falling on DuPage County and within the watershed of the DuPage River was stored naturally in the soils and surface depressions where it fell. Over time, the natural drainage system of creeks and rivers developed a capacity for conveying stormwater that was balanced with these watershed characteristics of soils, vegetation and topography. Human land development practices – starting with agriculture, and continuing to urban development - offset this natural balance by eliminating naturally occurring storage, reducing the infiltration of stormwater into the ground, and generally increasing the velocity and quantity of the runoff. Because receiving streams do not naturally have the capacity to transport these increased flows, downstream flooding and reduced water quality have resulted. Working to bring natural and human systems and processes into greater balance, through engineered and natural systems and processes, is the purpose of the DuPage County Stormwater Management program, and a central purpose of this Watershed Plan.
In addition to documenting these ongoing issues and concerns for the East Branch, including physical conditions and pollutant loads, this Watershed Plan inventories the many restoration and protection activities being taken by public, non-profit and private stakeholders throughout the watershed. While no individual watershed plan using the EPA guidelines described above has been prepared, the East Branch has been the subject of monitoring, assessment, regulatory actions, and engineering studies. These water quality conditions, restoration, monitoring and water quality projects either ongoing, planned or possible, are compiled in this Plan. Evaluating the East Branch’s water quality problems against the The DuPage County Stormwater wide range of possible solutions, and identifying the Management Plan, approved by the DuPage stakeholders and resources needed to carry these County Board in September 1989, states that through is a primary purpose of this Watershed Plan. the following components will be part of each watershed plan: This Plan has been structured to serve several important purposes, including watershed • updated and revised flood plain maps; management, flood resilience, pollution prevention, • recommended remedial and environmental restoration. It reflects both the improvement projects, both structural and nonstructural, to requirements of the DuPage County Stormwater alleviate current and anticipated Management Plan (DCSMP), approved by the flooding problems; DuPage County Board in September 1989, and the • identification of natural storage areas, including wetlands; recommendations of US EPA’s Handbook for • identification of significant natural Developing Watershed Plans to Restore and Protect areas; Our Waters (EPA 841-B-08-002). • identification of groundwater recharge areas within the watersheds; While a specific East Branch watershed plan has not • recommended site runoff and been completed to date, it has its roots in County- watershed storage criteria balanced and region-wide efforts from the 1990s. The initial with the watershed capacities; and • flood forecasting recommendations. effort to integrate issues and studies into a watershed 10
3. Introduction plan was the original Upper DuPage River Watershed Implementation Plan, which was prepared in 1997. Covering both the East and West branches of the river, the original plan was one of the first watershed plans in the state. This plan was updated in 2004 by staff of The Conservation Foundation, working with many stakeholders; along with the issuance of Total Maximum Daily Loads (TMDLs) for the East Branch and West Branch Salt Creek. The plan helped initiate more watershed-focused efforts in the County and watershed.
One of the initiatives stemming from the Impairment, Designated Uses, and original DuPage River Watershed TMDLs Implementation Plan is the DuPage River Salt The US EPA defines an impaired waterbody as a Creek Workgroup (DRSCW). The DRSCW was waterbody (i.e., stream reaches, lakes, waterbody formed in 2005 as a forum for municipalities, segments, etc.) that because of pollution or physical wastewater treatment facility operators, and conditions does not meet established standards for its designated uses: the uses the waterbody environmentally-focused non-profit would be expected to provide to the public, and for stakeholders to respond to impairment issues aquatic life, given the local climate, watershed (see text box at right) and the TMDLs characteristics, and surrounding land uses. The established for the East and West Branches of designated uses for the East Branch include fish consumption, supporting aquatic life, and contact the DuPage River and Salt Creek. The DRSCW recreation. works to prepare comprehensive data sets for local watersheds in order to determine and If an Illinois waterbody is found through address stresses on the aquatic systems in each monitoring to be impaired, it is placed on the IEPA “Section 303(d)” list of impaired waters. For each of the three river systems, and works to impaired waterbody, a plan called a Total implement cost-effective projects to improve Maximum Daily Load or TMDL must conditions in a cost-effective way. The DRSCW ultimately be prepared to address how pollutant prepared water quality and biotic assessments loads will be reduced to levels that will support the of the East Branch in 2007 and 2011, both of designated uses. A TMDL is an estimation of the maximum amount of a pollutant that a waterbody which were used as resources in the preparation can receive and still meet water quality standards. of this Watershed Plan. It assesses contributing point and nonpoint sources to identify pollution reductions necessary for In addition to reflecting County-wide standards designated use attainment. A TMDL identifies the and other higher-level directives, this Plan also source of impairment and provides reduction recognizes many municipal efforts and estimates to meet water quality standards. Pollutant reductions are then allocated to initiatives whose goals and outcomes will help contributing sources, thus triggering the need for achieve this Plan’s goals. Local efforts such as pollution control and increased management the City of Woodridge’s stream assessment responsibilities amongst sources in the watershed. program are part and parcel of the ongoing, stakeholder-driven process for implementing this Plan’s goals. Throughout the Plan, municipal plans, goals and initiatives have been integrated into the analysis and recommendations.
3.1.3. Resilience and Watershed Planning Because impacts and damage from overbank and other types of flooding also continue to be a driving concern within the East Branch watershed, this Plan has a special focus on planning for watershed resilience: Identifying strategies and actions that will bolster the watershed’s ability
11
3. Introduction
to prevent, withstand and recover from the acute shocks and chronic stresses in the watershed, such as severe storms and flooding. Major storms and natural flooding will continue to be a fact of life in the East Branch watershed; resilience strategies address the need to protect buildings and infrastructure when floods occur, but also to take actions that can prevent damage and disruption to homes, properties, roads and natural areas when floods, storms, and other natural events do occur. Throughout this Plan, this concept of “resilience” will be used to describe the process of helping people, communities, and institutions prepare for, withstand, and emerge stronger from the acute shocks and chronic stresses caused by flooding and storms.
3.1.4. Addressing Unmet Needs in the East Branch DuPage River Watershed Another objective of this Plan is to identify and integrate unmet needs from post-flood recovery efforts in heavily affected areas of the East Branch watershed. While this specific approach is not typically used in a water quality-oriented watershed plan, it is important to the approach in the East Branch watershed. By evaluating flood-related mitigation and investments in the context of a watershed plan, the County and other stakeholders can find synergies between programs such as buyouts, through which chronically flooded structures are purchased and demolished, and watershed restoration opportunities, such as wetland or stream corridor restoration in areas along the river. Looking at unmet needs also provides an opportunity to engage residents and businesses who have been adversely affected by the East Branch’s condition in envisioning different future outcomes with positive social and economic benefits - such as making flood control improvements, creating neighborhood greenspace after buyouts, or strengthening communication and infrastructure systems so that floods, extended wet or dry periods, or harsh winter conditions cause less harm. Unmet needs are incorporated as part of the prioritization process that is used in this Plan.
3.1.5. Statement of Plan Goals This Plan for the East Branch watershed provides an “umbrella” document integrating the results of municipal, County, non-profit and educational plans and studies into a vision for the desired future of the East Branch watershed’s natural and human environment. Specific projects and strategies in the Plan, as well as recommended watershed- and County-wide actions, all are oriented towards achieving the “best case” future condition envisioned in these goals.
This Plan’s overall goal is to enhance resilience, environmental quality, and community cohesion throughout the East Branch watershed. This overall goal has three distinct, though inter-related, parts.
Goal #1: A resilient watershed.
In a resilient watershed:
• Residents, businesses, commuters, utilities, and public service providers will have more rapid and accurate predictions of adverse weather and particularly flood events, with more time to anticipate and avoid impacts – instead of reacting.
12
3. Introduction
• The County’s transportation and distribution systems, its public and emergency services, and its utility systems will experience less disruption during adverse weather and flood events, reducing the severity and “shock” to the community and economy. • Fewer structures and less critical infrastructure will be damaged when flooding does occur, reducing primary (damage repair/buyout) and secondary (business loss/homeowner disruption/social services) costs. • Preventive maintenance will be sufficiently funded, and the County and municipalities will have sufficient legal authority, to ensure that public and private investments throughout the watershed are protected and water infrastructure systems will function well. • Updated regulatory structures and policies will incentivize the use of best practices for watershed resilience and damage prevention as development and public investment occur.
Goal #2: A watershed with enhanced environmental quality and minimal degradation, where beneficial uses are fully attained.
In a future with enhanced environmental quality,
• Storm and flood events will carry smaller or minimal non-point source pollutant loads into the watershed’s surface and ground waters, reducing impacts from erosion and supporting healthy aquatic habitats. • Impacts from hydrologic modification will be reduced or eliminated through a combination of upstream controls and in-stream restoration. • Degraded stream segments will be restored using design and engineering strategies that are compatible with the needs of the surrounding community. • Capital investments, land purchases, buyouts, and preventive measures will be coordinated to improve natural function, reduce pollutant loads, and enhance environmental quality. • Sanitary and combined sewer overflows will be mitigated, preventing detrimental impacts to water quality. • In-stream structures not required to support the County’s economy and community systems will be removed, and the aquatic health impact of necessary in-stream structures will be mitigated through engineering and environmental restoration techniques. • Where possible, land acquisitions, park and natural areas management, and community development planning will incorporate natural buffers for the East Branch, providing for natural floodplain and river dynamics.
Goal #3: Greater Community Cohesion.
In a future with greater community cohesion throughout the watershed:
13
3. Introduction
• Residents, public agencies and businesses will know about and value the East Branch watershed as a natural system, and understand how “upstream” actions affect “downstream” outcomes. • A dynamic and effective stakeholder network for watershed issues will be an ongoing presence in DuPage County, similar to economic development, social service and recreation networks today. • Broad support will be secured readily for public investments that improve resilience, enhance and protect environmental quality, and mitigate or prevent flood damage. • Social and professional organizations will be knowledgeable about and engaged in watershed and resilience issues, contributing diverse expertise to resilience plans and actions. • Residents of flood-affected or environmentally degraded areas will be active participants in dialogue about the options and future scenarios for themselves and their neighbors. • Residents, businesses, employees and volunteers will have rapid, easy access to information on the watershed, and ways they can participate in its enhancement and protection.
3.2. Watershed Planning Process & Data Collection Preparing and adopting a watershed plan involves a different process from other municipal or agency plans such as a municipal Comprehensive Land Use Plan or the County’s annual Financial Plan. First, by nature, a watershed plan must be a multi-jurisdictional effort since surface waters cross multiple legal boundaries. Second, a watershed planning process must aggregate a wide range of different types of data from many different types of organizations, whose information management needs and procedures differ dramatically. For example, water quality data collected by the Illinois Environmental Protection Agency (IEPA) for a 303(d) list will not use the same protocols or sampling methods as data collected by non-profit organizations; likewise, the goals of a municipal Comprehensive Plan for stormwater management or stream restoration will be different from, but complementary to, the goals of a regional open space or conservation strategy. The sections that follow describe the process that has been used to identify the jurisdictions, stakeholders and data sources needed to create a strong framework for planning and implementation in the East Branch watershed.
3.2.1. Identifying Watershed Jurisdictions and Stakeholders A watershed’s “stakeholders” are both the geographic jurisdictions in the watershed – those entities with legal authority over the physical area and infrastructure of the watershed, such as municipalities, counties, townships, sanitary districts, and forest preserves - and the non- geographic stakeholders whose lands, activities and areas of operation have authority or influence within the watershed. Municipalities and counties with land in the watershed are of primary importance, since these jurisdictions control so many aspects of land use and development, water infrastructure, emergency management, flood control and transportation; however, many non-jurisdictional stakeholders, such as large landowners and influential community organizations, are likely to have equally significant roles in watershed policy development and particularly implementation. 14
3. Introduction
For the East Branch watershed, Table 3-1 below lists the jurisdictions in the watershed, and the amount of the watershed’s land area each jurisdiction controls. Municipal jurisdictions are shown in Exhibit 2. While municipal and County unincorporated areas are by definition mutually exclusive (i.e. area within one village or city cannot be under the jurisdiction of another), the area within Township, Illinois Department of Transportation (IDOT) right-of-way, School District, and Forest Preserve lands may be in one or more municipal or County jurisdictions.
Table 3-1. Municipal Jurisdictions within the East Branch DuPage River Watershed
Area in East Branch Watershed Percent of Total Jurisdiction (square miles) Watershed Area Counties DuPage 75.2 (48,131 acres) 92.5% Will 6.0 (3,863 acres) 7.5% Municipalities (DuPage County portion of Watershed) Village of Downers Grove 14.49 19.27% Village of Lisle 6.54 8.69% Village of Glen Ellyn 6.30 8.38% Village of Lombard 6.25 8.32% Village of Woodridge 5.79 7.70% Village of Glendale Heights 3.68 4.89% City of Wheaton 3.49 4.64% Village of Westmont 2.28 3.03% Village of Bloomingdale 2.22 2.96% Village of Addison 1.37 1.83% City of Naperville 1.31 1.74% City of Darien 0.48 0.63% Village of Bolingbrook 0.20 0.27% Village of Oakbrook 0.11 0.15% Village of Carol Stream 0.03 0.04% City of Warrenville 0.00 0.00% Townships Lisle 23.32 31.01% Milton 20.94 27.85% Downers Grove North 13.04 17.35% Bloomingdale 9.41 12.51% Winfield 0.18 0.24% Addison 0.13 0.18% Naperville 0.00 0.00% Other Jurisdictions Forest Preserve District of DuPage County IDOT Right of Way School Districts Sanitary Districts In addition to government units that manage the watershed’s land area, many Illinois and U.S. federal agencies also have important roles in watershed management and particularly in flooding and floodplain management. Within DuPage County’s government structure, there are many departments and agencies that have specific responsibilities important to watershed and resilience planning. In several cases, federal, state, and county departments have similar missions, such as emergency management and environmental protection; in others, non-
15
3. Introduction
governmental organizations such as the Morton Arboretum and The Conservation Foundation may have missions and resources that are highly complementary to those of government agencies. The stakeholders and departments listed in Table 3-2 represent those that have been identified as having a substantial and defined role within the East Branch watershed at this time, but the list is by no means exclusive of other organizations or agencies that may be valuable partners in planning and implementation.
Table 3-2 Non-Geographic Stakeholders & County Departments
Illinois Agencies U.S. Federal Agencies DuPage County Non-Governmental Departments Organizations and Work Groups Illinois Department of US Fish & Wildlife Service Department of Public DuPage County Natural Resources (IDNR) (USFWS) Works Community Foundation US Environmental Illinois Environmental Economic Development Protection Agency (US Choose DuPage Protection Agency (IEPA) & Planning EPA) Illinois Emergency Federal Emergency Office of Emergency DuPage River/Salt Creek Management Agency Management Agency Management Workgroup (IEMA) (FEMA) Illinois Department of Federal Highway Division of Morton Arboretum Transportation (IDOT) Administration (FHWA) Transportation Community US Army Corps of The Conservation Illinois Tollway Development Engineers Chicago District Foundation Commission SCARCE (School & Community Assistance for Health Department Recycling & Composting Education) Geographic Information Chicago Wilderness Systems (GIS)
Each public sector stakeholder has different, and sometimes overlapping, responsibility for key aspects of watershed management and flood control. Table 3-3 below relates the public sector stakeholders to their responsibilities in five areas that affect watershed function, non-point source pollution, and flood and emergency management:
Land Conservation and Management: Because of the importance of maintaining natural areas and vegetation to protecting watershed hydrology, and providing space for flood events to occur without damage to roads and structures, land conservation and land management activities such as open space acquisition, tree planting and urban forestry, and wetland or riparian area restoration constitute an essential element of watershed management and planning.
Planning & Development: The amount, location and density of development and impervious surfaces is governed to a large extent by County and municipal planning, zoning and development review policies and standards. Comprehensive plans that incorporate watershed
16
3. Introduction
planning principles can provide important support to sound watershed management and resilience actions.
Water Infrastructure: Agencies responsible for providing safe drinking water supplies, wastewater treatment and disposal, stormwater management and flood control constitute one of the most important groups of stakeholders, since this infrastructure immediately affects river systems, water quality, and flood management.
Flooding and Emergency Response: In addition to IEMA and FEMA, which deal with floodplains, flood insurance, damages and buyout programs, many agencies not otherwise concerned with watershed and water quality issues are directly engaged through the economic, social and emergency services impacts of flood events and flood recovery.
Transportation: Transportation has many impacts on the watershed, including pollution caused by roadway runoff and deicing, water quality and stream channel impacts from roadway culverts and bridges, and the hydrologic impacts of roadway-related impervious surfaces and conveyance systems. However, transportation investments can be and often are designed to improve water quality and watershed conditions, providing multiple public benefits. An overview of the transportation network is provided in Exhibit 3.
Table 3-3 Public Sector Stakeholders and Areas of Responsibility
Land Planning & Water Flooding & Transportation Conservation Development Infrastructure Emergency & Mgmt Response
Traffic FlowTraffic Buyout Planning - Buyout Salt Dispersal Traffic Safety Snow Removal Buyout Programs Buyout Road Maintenance Land Conservation Land Safe Drinking Water Development Review Post Zoning & Subdivision & Zoning Urban ForestryTrees / Hydrology/ Conveyance Hydrology/ Flood Control Structures Control Flood Emergency Management Comprehensive Planning Comprehensive Wastewater Management DCCSFPO Implementation Wetland/Riparian Restoration
DuPage County Municipalities Townships IDOT/FHWA Illinois Tollway IEMA/FEMA Forest Preserve Sanitary Districts School Districts IEPA/US EPA IDNR/USFWS
17
3. Introduction
3.2.2. Stakeholder Data Collection Process An understanding of the unique features and natural processes associated with the East Branch DuPage River watershed, as well as, its current and potential future conditions, is critical to developing an effective watershed plan that provides planning, policy and improvement recommendations for future resilience. As such, developing a process for ongoing data collection and sharing among stakeholders is a key component of the planned stakeholder process.
As part of this watershed planning process, DuPage County Stormwater led an extensive and interactive data gathering process to obtain data from governmental and non-governmental entities and inter-agency working groups located in or active within the East Branch watershed. This process provided baseline data needed to meet the requirements for a watershed-based plan, and also helped develop a better understanding of how stakeholders can communicate and share information in the future.
Staff members from each municipality (i.e. incorporated city or village) with land in the watershed were contacted by the County to begin describing the types and locations of available data applicable to this plan. A questionnaire was developed (Appendix A) and provided to each municipality. Completed questionnaires and a summary of responses are provided in Appendix A. The questionnaire focused on types of data required for an IEPA-compliant watershed plan, but also looked at issues and data of particular importance to the East Branch and the persistent flooding issues experienced in watershed municipalities. The key areas of inquiry were:
1. Municipal Codes, Open Space/Green Infrastructure Plans, and Comprehensive Plans: Status, and any planned actions or updates 2. Stormwater Management and Flooding: Adopted policies, actions and planned investments; funding sources; buyout program plans and status; records from the April 2013 floods 3. Environment, Water Quality and Sustainability: Actions of local committees or sustainability initiatives; local stream restoration/stabilization, habitat, and conservation projects; locally-collected water quality data 4. Public Outreach and Engagement: Recent Municipal Separate Storm Sewer System (MS4) or public engagement, local outreach to flood-affected areas, and local surveys on environment, flooding, land use and water quality topics. 3.3. Watershed Physical and Water Quality Data Data that characterizes the physical condition and water quality of the East Branch comes from a variety of sources. Water quality monitoring conducted periodically by IEPA provides a baseline of the presence and concentration of various pollutants. Based on the results of these data, which are described in Section 4.11, the East Branch has been listed as “impaired” by the IEPA (see sidebar, Section 3.1.2) for multiple pollutants and conditions that exceed the limits established by the IEPA for the East Branch’s designated uses. In response to the listing, the IEPA prepared the Total Maximum Daily Loads for the East Branch DuPage River, Illinois in
18
3. Introduction
2004, addressing pollution from chlorides (commonly caused by runoff from salted roadways) and low levels of dissolved oxygen (DO), which reduce the River’s ability to support aquatic life.
As of January 2015, these TMDLs are in the process of being updated by the IEPA. As noted in the summary response table in Appendix A, a handful of municipalities and several of the non- governmental and inter-agency stakeholders in the watershed are also collecting watershed data, including stream channel assessments, flood data reports, and water quality information. Some of this data was available for preparation of this Plan; further data collection and sharing on water quality will be important for stakeholder engagement and implementation as this Plan moves ahead.
3.3.1. Flooding-Related Data & Analysis A distinguishing component of this Plan is its inclusion of data on flooding and flood impacts, which is intended to provide a strong foundation for greater flood mitigation and resilience planning by the watershed’s jurisdictions and stakeholders. One major focus was data from the April 18, 2013 flood event, when more than 5 to 6-inches (~130 mm) of rain fell in the Chicago area in 24 hours from a slow-moving system falling on pre-saturated ground. The extent of the road closures, emergency services, transportation disruption, structure damage, and 911 or other emergency calls makes the April 18, 2013 flood event an instructive “maximum case” for assessing potential flood impacts in a variety of areas throughout the watershed. Many different types of data including road closures, 911 and non-emergency calls, numbers of flood damaged structures and areas of inundation were collected from multiple agencies and departments and are referenced throughout this Plan.
3.3.2. Demographics & Socioeconomic Data An extensive look at the demographic and socioeconomic conditions in the watershed was also completed for this Plan, extending beyond the “basics” of population and development typically included in a watershed plan. As part of assessing needs and recommending actions, the Plan describes the spatial relationship of watershed flooding and water quality issues to areas of low and moderate income population within the watershed. This detailed evaluation of demographic and socioeconomic data provides a much stronger context for implementation, and particularly for resilience planning, as this analysis relates watershed planning and resilience principles to the conditions in disadvantaged or potentially vulnerable populations, disadvantaged neighborhoods, and even in industries that are integral to the County’s economy and potentially at risk from flooding and adverse conditions. This analysis will help the County and others leverage implementation resources, such as Community Development Block Grants and social initiatives, that can help carry out different aspects of the Plan. 3.4. Public Outreach & Stakeholder Engagement In a multi-jurisdiction watershed with many actors and authorities, engaging both specific stakeholders – persons or organizations with interests or concerns, and those who may be affected by related actions – and the public at large within the East Branch watershed is necessary. While different efforts have been underway in the larger DuPage River watershed, such as the DuPage River/Salt Creek Workgroup, there has not been a concerted effort to bring
19
3. Introduction
together the many jurisdictions and stakeholders in the East Branch watershed around its specific geography and issues. Thus DuPage County has used the preparation of this watershed plan as a platform to begin stakeholder engagement, to outline and better articulate the topics and needs of concern in the watershed, and to build a strong foundation for advancing watershed-based decision-making and engagement in the future.
As described in Section 3.2 above, the data collection process for this Plan was an integral part of the overall stakeholder engagement effort. The data collection process also is an ongoing activity that has carried throughout the development of this Plan, in order to assist the stakeholders in identification of their past, current and future policies and work products. By compiling and analyzing the data collected, holding stakeholder meetings, and using brainstorming sessions, stakeholders were able to identify water quality issues, related initiatives, and unmet needs throughout the watershed. This facilitated the development of recommendations to provide and promote future resilience in the watershed. As the outreach began, additional stakeholders were identified and provided a variety of information to be included in the Plan.
Outside the data collection effort, DuPage County Stormwater Management (DCSWM) began convening a stakeholder group before the Plan was developed, and has carried this process through preparation of the Plan and the adoption process. Key steps that have been taken to date include the following:
Additional meetings will be added to the list below.
DuPage Steering Committee
• December 18, 2014 (Full Committee) • December 22, 2014 (County Staff) • January 8, 2015 (Full Committee) • January 26, 2015 (Full Committee) • February 2015 (TBD)
East Branch DuPage River Resiliency Plan Public Meetings
• January 14, 2015 (Lisle) • February 5, 2015 (Wheaton)
Other General Stakeholder Meetings
• November 21, 2014 (Initial Advisory Group Meeting for Region) • January 7, 2015 (Non-Profit Organizations) • January 8, 2015 (Non-Profit Organizations) • January 14, 2015 (Non-Profit Organizations) • January 14, 2015 (Park Districts, Chambers, Townships, Schools) • January 23, 2015 (Green Government Council) • January 27, 2015 (Finance Committee – All County Board Members)
20
3. Introduction
• February 3, 2015 (DuPage Stormwater Management Committee – County Board and Municipal Members) • February 5, 2015 (East Branch Environmental Focus Group)
Other Outreach
• Flooding and Quality of Life Survey. Currently over 700 respondents. Results are currently being analyzed. 3.5. Plan Adoption The adoption process for a Watershed Plan allows for comment and review by the public and many agencies prior to submittal to Illinois EPA, which will approve the Plan as sufficient to give the watershed priority in competition for §319 non-point source reduction funds. The adoption process for this Plan includes the steps below:
• Preliminary draft for Stormwater Working Group review – February 9, 2015 • Stormwater Committee Opening of 30 day Public Comment Period -February, 2015 • IEPA preliminary comment review – February 2015 • Final draft – mid-February 2015 • Stormwater Committee Approval – March 2015 • DuPage County Board Approval – March 2015 • Final draft to IEPA for approval - May 1, 2015
Once adopted, the East Branch Watershed Plan will be incorporated into Appendix N (East Branch DuPage River Watershed Plan) of the DuPage County Stormwater Management Plan.
As discussed in Section 8, implementation portions of the adopted Plan are expected to be incorporated into many different plans and grant applications that further this Plan’s goals and objectives. Development of a complete Watershed Plan also will provide projects identified within the plan with a competitive advantage in competing for §319 funds when evaluated against other projects that have not been vetted through such a process.
21
4. Watershed Characteristics Assessment This section of the Plan describes the physical characteristics and resources in the East Branch watershed, along with some of the human-made features such as cultural resources and natural areas that are important parts of the watershed’s physical context. The section is intended to describe the interaction of the watershed’s natural systems, including soils, topography, vegetation, climate and flow paths, with the built environment and infrastructure systems. Land use, demographic and transportation systems are described in Section 5.2.
Understanding the condition of features such as riparian areas, groundwater, and historic and existing wetlands is crucial to planning for implementation, especially as stormwater management and flood control policies and practices focus on infiltration and restoration. The DuPage County Stormwater Management Plan requires that each watershed plan prepared within the county identify remedial measures to protect wetlands, riparian environments, and recharge areas threatened by stormwater management activities, so that these can be coordinated with County and municipal open space acquisition programs. The most recent revisions of the DuPage County Countywide Stormwater and Flood Plain Ordinance (DCCSFPO) encourage the use of green infrastructure practices to reduce the volume of runoff, as well as minimize the load of pollutants associated with runoff. Each of these important policy and regulatory measures is intended to maximize restoration of natural functions, protection of existing functions, and opportunities to make public investments that will achieve multiple objectives. 4.1. The East Branch DuPage River Watershed The watershed of the East Branch DuPage River lies approximately 30 miles west of downtown Chicago (Exhibit 1). From its headwaters in the Village of Bloomingdale, the East Branch drains approximately 81.2 square miles (52,000 acres) as it flows in a southerly direction approximately 24.2 miles before meeting its confluence with the West Branch DuPage River between Naperville and Bolingbrook. From this confluence, the DuPage River flows southerly through Plainfield before joining the Des Plaines River, which continues to flow south to meet the Kankakee River west of Channahon and form the Illinois River, a tributary of the Mississippi River. Water flowing through the East Branch DuPage River ultimately flows into the Gulf of Mexico.
Table 4-1 Drainage Areas of the East Branch DuPage River
Drainage Location Square Miles Acres Upstream of Butterfield Road 26.2 16,774 Upstream of Royce Road 76.0 48,608 Full Watershed (Upstream of 81.2 51,994 confluence with West Branch)
22
4. Watershed Characteristics Assessment
4.1.1. Mainstem of the East Branch DuPage River The mainstem of the East Branch DuPage River traverses many of the major transportation routes as it makes its way from its headwaters, which are north of Glen Ellyn Road in Amherst Lake. From this point, the mainstem flows to the east-southeast passing through the East Branch Forest Preserve and under Army Trail Road and North Avenue (Illinois Route 64) where the mainstem joins with Armitage Creek. The East Branch DuPage River continues to flow to the south through the Churchill Woods Forest Preserve, under Crescent Boulevard, Columbine Avenue (Illinois Route 53) and Roosevelt Road before its confluence with Glencrest Creek north of Butterfield Road (Illinois Route 56) and Lacey Creek within the Hidden Lakes Forest Preserve. Continuing south, the mainstem passes through the Morton Arboretum and under Route 53 before its confluence with Willoway Brook north of Warrenville Road. The mainstem then passes under the I-88 Ronald Reagan Memorial Tollway and joins St. Joseph and Swartz Creeks north of Ogden Avenue. Downstream of Ogden Avenue, the East Branch DuPage River flows under Burlington Avenue and the Burlington Northern Railroad before joining Rott Creek north of Short Street. The mainstem then resumes flow under Maple Avenue, Four Lakes Avenue, and Summerhill Drive before its confluence with Prentiss Creek north of Hobson Road and Crabtree Creek south of 75th Street. The last portion of the East Branch DuPage River continues south from 75th Street where it passes into Will County and under Royce Road and Washington Streets before joining the West Branch DuPage River approximately 3 miles south of the DuPage/Will County line.
4.1.2. East Branch Subwatersheds A more detailed look at smaller drainage areas or subwatersheds in the East Branch is helpful in locating and characterizing specific problem areas. There are 11 major subwatersheds in the East Branch watershed, which are listed in Table 4-2 below. There are also 6 minor named subwatersheds located within the watershed: East Branch Tributary #1, East Branch Tributary #3, East Branch Tributary #6, East Branch Tributary #7, 22nd Street Tributary, and Glen Park Tributary. The stream length and drainage area for each subwatershed including the East Branch DuPage River mainstem are listed in Table 4-2. Subwatersheds are shown in Exhibit 4.
Table 4-2 East Branch Mainstem and Subwatershed Information
Subwatershed Name Stream Length Drainage Area (Miles) (Square Miles) East Branch Mainstem 24.2 33.8 Armitage Creek 2.2 2.1 Army Trail Road Tributary 0.3 0.4 Crabtree Creek 1.3 1.5 East Branch Tributary #2 1.2 1.2 Glencrest Creek 1.6 2.7 Lacey Creek 3.0 4.6 Prentiss Creek 3.0 7.1 Rott Creek 3.6 6.0 St. Joseph Creek 12.0 11.2 Swift Meadow 1.5 0.9 Willoway Brook 3.0 4 East Branch Tributary #1 - 0.6
23
4. Watershed Characteristics Assessment
Subwatershed Name Stream Length Drainage Area (Miles) (Square Miles) East Branch Tributary #3 - 0.5 East Branch Tributary #6 - 1.9 East Branch Tributary #7 - 0.9 22nd Street Tributary - 0.8 Glen Park Tributary - 0.7 Total 56.9 81.2
Armitage Creek – The Armitage Creek subwatershed covers approximately 2.1 square miles of area in Glendale Heights and unincorporated Bloomingdale Township in northern DuPage County, Illinois. The land use within the subwatershed is primarily residential with commercial and industrial parks and a golf course located in the headwaters. The Armitage Creek mainstem originates at the Glen Point Business Park detention ponds located west of Bloomingdale Road and flows approximately 2.2 miles before its confluence with the East Branch DuPage River north of North Avenue (Route 64).
Army Trail Road Tributary– The Army Trail Road Tributary subwatershed covers approximately 0.4 square miles of area in northeastern DuPage County, Illinois. This subwatershed includes portions of the Villages of Addison and Bloomingdale and unincorporated Bloomingdale Township. The land uses within the subwatershed include residential and open space with small areas of commercial, industrial, institutional, and vacant lands. The Army Trail Road Tributary originates within a storm sewer system that parallels Army Trail Road near the intersection of Army Trail Road and I-355 Tollway and flows west for approximately 0.3 miles before its confluence with the East Branch DuPage River downstream of Valley View Road.
Crabtree Creek – The Crabtree Creek subwatershed covers approximately 1.5 square miles of area in the Village of Woodridge in southern DuPage County, Illinois. The land use within the subwatershed is residential and commercial development with small areas of corporate, open space, highways, and institutional areas. The Crabtree Creek mainstem begins on the west side of I-355 and flows approximately 1.6 miles westerly before its confluence with the East Branch DuPage River downstream of 75th Street.
East Branch Tributary #2 – The East Branch Tributary #2 subwatershed covers approximately 1.2 square miles in northern DuPage County, Illinois. The subwatershed includes parts of the Villages of Glen Ellyn and Glendale Heights, and areas of unincorporated Milton and Bloomingdale Townships. The land use within the subwatershed is primarily residential along with several commercial/industrial developments, a small wetland, and a neighborhood park. The East Branch Tributary #2 mainstem originates at a detention ponds located north of James Court and flows approximately 1.2 miles before its confluence with the East Branch DuPage River south of North Avenue (Route 64), just upstream of the Great Western Trail.
Glencrest Creek – The Glencrest Creek subwatershed covers approximately 2.7 square miles within the Village of Glen Ellyn and City of Wheaton in central DuPage County, Illinois. The
24
4. Watershed Characteristics Assessment
land use within the subwatershed is primarily residential along with several commercial developments along Roosevelt Road (Route 38). The Glencrest Creek subwatershed is divided into an upper and lower watershed. The upper watershed is comprised of a 2.5 mile storm sewer conveyance system with several detention ponds and lakes. The lower watershed comprises approximately 1.6 miles of open channel beginning at Park Boulevard. Flow within the lower watershed generally flows to the east and enters the East Branch DuPage River between Roosevelt Road (Route 38) and Butterfield Road (Route 56).
Lacey Creek – The Lacey Creek subwatershed includes 4.6 square miles in central DuPage County, Illinois. The subwatershed includes the Villages of Downers Grove and Oak Brook and areas in unincorporated Milton, York, and Lisle Township. The land use is separated into two distinct areas by the I-88 and I-355 Tollways. East of the tollways contains a mixture of land use including residential subdivisions, institutions, commercial, office research, open space, and a limited number of undeveloped lands. Land use west of the tollway consists primarily of open space and agricultural lands, with some commercial and office research development along the northern edge of the subwatershed. Lacey Creek originates at a detention pond locate south of 35th Street, between Fairview Road and Brougham Lane. From the ponds, Lacey Creek flows north and west, approximately 3.0 miles through the campus of Midwestern University, the Morton Arboretum, and the Lyman Woods and Hidden Lake Forest Preserves before its confluence with the East Branch DuPage River south of Butterfield Road (Route 56), inside the Hidden Lake Forest Preserve.
Prentiss Creek– The Prentiss Creek subwatershed covers approximately 7.1 square miles within the Villages of Lisle, Woodridge, and Downers Grove in southern DuPage County, Illinois. The land use within the subwatershed is primarily residential with a scattering of commercial, industrial, and institutional developments, a golf course, and parks. Prentiss Creek originates within a series of online detention facilities commencing with Maple Lake. From its headwaters, the creek flows west approximately 3.0 miles through a series of open channels and storm sewers before its confluence with the East Branch DuPage River immediately upstream of Hobson Road.
Rott Creek– The Rott Creek subwatershed covers approximately 6.0 square miles in central DuPage County, Illinois. The subwatershed includes parts of the Village of Lisle, Cities of Naperville and Wheaton, and areas of unincorporated Milton and Lisle Townships. The land use within the subwatershed is primarily open space, residential and office research with small pockets of commercial, industrial, and institutional developments and vacant land. Rott Creek subwatershed is divided into two distinct parts, separated by Naperville Road. The upper portion of the subwatershed contains a series of storm sewers, open channels, and a substantial amount of flood storage. The lower section, comprising the Rott Creek mainstem begins at the two outfalls of the Hesterman Drain just east of Naperville Road. From this point, the creek flows approximately 3.6 miles to the south before its confluence with the East Branch DuPage River north of Short Street, east of Lisle Community Park.
St. Joseph Creek – The St. Joseph Creek subwatershed covers approximately 11.2 square miles within the Villages of Downers Grove, Westmont, and Lisle and portions of 25
4. Watershed Characteristics Assessment
unincorporated Lisle and Downers Grove North Townships in southern DuPage County, Illinois. The land use within the subwatershed is primarily residential with smaller areas of commercial, industrial, and institutional developments, a golf course, forest preserves, parks, and other open lands. From its headwaters near 63rd Street, the creek flows north and northwest for approximately 12.0 miles to its confluence with the East Branch DuPage River north of Ogden Avenue.
Swift Meadows– The Swift Creek subwatershed covers approximately 0.9 square miles in northern DuPage County, Illinois. The subwatershed includes parts of the Villages of Addison and Bloomingdale, and areas of unincorporated Bloomingdale Township. The land use within the subwatershed is primarily residential and open space, with small pockets of commercial, industrial, and institutional developments and vacant land. The headwaters of Swift Meadows originate within the Swift Meadows Business Park east of Swift Road. Flow from the headwaters travels west 1.4 miles through Swift Meadows Forest Preserve before its confluence with the East Branch DuPage River south of Army Trail Road.
Willoway Brook – The Willoway Brook subwatershed covers approximately 4.5 square miles within the City of Wheaton, Villages of Glen Ellyn and Lisle, and unincorporated Milton and Lisle Townships, in central DuPage County, Illinois. The land use within the subwatershed is primarily residential and open space (Morton Arboretum and the Danada Forest Preserve being the largest) with a scattering of commercial, office, and institutional developments. Willoway Brook originates at a storm sewer outlet located near the dead end of Windsor Drive. From its headwaters, the stream flows south to southeasterly approximately 3.0 miles before its confluence with the East Branch DuPage River north of Warrenville Road, about halfway between Warrenville Road and Route 53.
4.1.3. Channel Conditions Streams are in constant dynamic equilibrium. Although it can be imperceptible over years or even decades, a stream in equilibrium moves within its floodplain both laterally and vertically over long periods of time. 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 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.
In general, the East Branch can be characterized as an urban stream with low gradients and extensive channelization. Canopy cover is limited due to development, resulting in higher summer stream temperatures and establishment of rooted vegetation within the stream bed. Contributions from point sources, including municipal wastewater treatment plant effluents are also significant, contributing phosphorus which may contribute to plant growth, but also provide higher flows during low flow and overall cooler temperatures. The IEPA has assessed the East Branch as partial. Identified causes of the less than full use support assessment include dissolved oxygen, chlorides, total nitrogen, habitat and flow alterations, suspended solids, 26
4. Watershed Characteristics Assessment
phosphorous, sedimentation/siltation, algal growth, and fecal coliform. The sources contributing to impairment include municipal point sources, runoff and storm sewers, development, stream modifications, and upstream impoundments.
The channel bottom is variable and includes areas of soft sediment, rock and cobble, and artificial armoring. Generally, the East Branch has been highly channelized through developed areas of DuPage County. The stream banks are approximately three to six feet high for most of the stream length, with the exception of the few areas where the channel flows into a detention pond or wide stream reach. Stream flow velocity is generally slow moving with a few sections where the flow is restricted due to hydraulic structures. 4.2. Climate and Precipitation Because the DuPage River watershed and particularly the East Branch watershed is affected significantly by overbank and other types of flooding, understanding climate and especially precipitation patterns in the Watershed is especially important.
4.2.1. Climate An important feature of local climate for watersheds is understanding extremes. Extended periods of heat or below-freezing temperatures both have impacts on watershed hydrology and function.
Illinois is situated midway between the Continental Divide and the Atlantic Ocean and is often underneath the polar jet-stream. The polar jet-stream is a focal point for movement between cold polar air masses from the north moving southward and warmer, tropical air from the south moving northward. The convergence of polar and tropical air causes Illinois to have a humid continental climate with hot humid summers and cool to cold winters with short frequent fluctuations in wind direction, cloudiness, humidity, and temperature. The average annual temperature of DuPage County is 48.6°F. The average temperature for the summer months (June – August) is 71.1°F with an average humidity of 74.3%; the highest recorded temperature was 105°F on July 14, 1995. The average temperature for the winter months (December – February) is 24.3°F with an average humidity of 77.8%; the lowest recorded temperature was - 26°F on January 20, 1985. Northern Illinois averages 140 days of temperatures at or below freezing annually. Some minor effects on the climate are produced by Lake Michigan, but these are generally minimal, especially in regard to temperature.
4.2.2. Precipitation The average annual precipitation in DuPage County is 36 inches. May, June, and August are the months with the highest precipitation, averaging over 4 inches each. On average there are 68 days annually with 0.1 inch or more of precipitation. The average annual snowfall is 32 inches in DuPage County. There are on average 48 days with 1 inch or more snow depth in a year. The most rainfall from a single event in the state of Illinois during a 24-hour period (spanning from July 17 – 18, 1996) was 16.94 inches in Aurora. This location is approximately 15 miles west from DuPage County, but it provides insight on the magnitude of the rainfall that is possible from a single event in this area.
27
4. Watershed Characteristics Assessment
Data for Northeast Illinois show an annual precipitation of 37.1 inches per year, however the variations from year to year can be large. For example, the lowest annual rainfall was 23.9 inches and the highest annual rainfall was 46.9 inches. Precipitation has been above normal every year from 2005 to most recent year included in the study.
There was record flooding along multiple rivers in northern Illinois in April 2013, including the East Branch DuPage River. The USGS gauge in Bolingbrook on the East Branch recorded a crest of 25.85 feet on April 18, 2013, exceeding the previous record of 24.04 feet from September 14, 2008. 4.3. Geology and Topography Understanding the geology and topography of a watershed provides important context on how the structure of soils and groundwater affects the shape and behavior of stream channels, the erodibility of streambanks, stream flows, and flooding. DuPage County lies in the Great Lake and Till Plaines Sections of the Central Lowland Province, a glaciated lowland that extends from the Appalachian Plateau on the east to the Great Plaines of Kansas, Nebraska, and the Dakotas to the west. The entire county is in the Wheaton moraine county subdivision of the Great Lake section, with the exception of the southwest part which is in the Bloomington ridged plain subdivision of the Till Plaines Section. The County is characterized by low broad, glacial moraines with numerous swamps and undrained areas. Bedrock is exposed and affects surface features only locally. The valley of the East Branch DuPage River originated during deposition of glacial materials and has not been significantly modified since. The southern reaches of the East Branch DuPage River are above a bedrock valley that Geologic History and the has been partially filled. DuPage River Watershed The soils found in the watershed have been derived from During the Pleistocene Era or “Ice Wisconsin Age glacial tills, glacial outwash, loess, and Age” advancing and receding glaciers alluvium. The surface soil layer and subsoils found in the covered much of North America. The watershed are typically a silty clay loam. Underlying Illinoian glacier extended to southern Illinois between 300,000 and material is generally clay loam with strata of sand and 125,000 years ago. It is the Illinoian gravel. The bedrock beneath is Ordovician Age assigned to glacier that is responsible for the flat, the Maquoketa and Galena Groups. farm-rich areas in the southern half of the state. The northeastern portion of Topography refers to the elevations of landscape that Illinois including the watershed area describes the configuration of its surface. Topography is an was also covered by the most recent glacial event known as the essential tool in the watershed planning process because Wisconsinan. topography defines the boundaries of the East Branch DuPage River watershed. For this watershed-based plan, The Wisconsinan began the DuPage County 2-foot topography was utilized (Exhibit approximately 70,000 years ago and ended around 14,000 years ago. It 5). was during this time that the temperatures began to rise and the ice The watershed, like most of the surrounding area, is retreated to form a landscape similar generally relatively flat; in most portions of the East Branch to the Alaskan tundra. As the watershed, relief in the uplands is typically less than 50 temperatures began to rise, the feet. Relief is greater along major valleys bordered by tundra was replaced by cool moist deciduous forests, and eventually 28 oak-hickory forests and prairies. The final retreat of the Lake Michigan lobe of the Wisconsin glacier is responsible for the formation of the Great Lakes and the landscape of the watershed. 4. Watershed Characteristics Assessment morainal deposits and often reaches a maximum of about 90 feet. The highest point in the watershed (878.6 feet) is located at Green Valley Hill (former landfill), a manmade feature. The highest natural point is the watershed (approximately 822 feet) is located near Wrightwood Court in Glendale Heights. The lowest point in the watershed (approximately 630 feet) is located near the creek’s confluence with the West Branch DuPage River. The difference in the highest and lowest points reflects a 192-foot change in elevation crossing from the northern to the southern section of the watershed. 4.4. Soils Soils and geology provide the key to understanding major hydrologic processes in a watershed, and understanding why certain areas of a watershed may especially be prone to erosion, experience standing water or ponding during rains, or be important sites to consider for wetland restoration. Soil properties are key components to consider when designing and implementing water quality and flood reduction treatment systems (known as “Best Management Practices” or BMPs). Some soils are naturally saturated for extended periods of time throughout the year and become what are referred to as hydric soils. Hydric soils generally hold water or infiltrate water very slowly.
Soils also exhibit different infiltration capabilities. Knowing the infiltration capabilities of the watershed’s soils will allow for the proper placement of infiltration BMPs, as well as the location of wetland creation/restoration projects and detention basins. Soils also exhibit differences in erodibility depending on their composition and slope. Erodibility of soils is especially important on construction sites where improper installation and maintenance of soil erosion and sediment control practices can lead to the release of sediment into creeks and lakes.
The 2001 DuPage County Natural Resource Conservation Services’ (NRCS) Soil Survey were used to conduct a soil analysis for the East Branch watershed. The data was used to map the soil series, extent of hydric soils, soil susceptibility to erosion, and the infiltration capacity. Deposits left during by the Hydric soils are wet frequently enough to Figure 4-1 Example Lake Michigan lobe of the produce conditions that are devoid of oxygen Soil Profile Wisconsin glacier are the (anaerobic) thereby influencing the plant species raw materials of the soils that can grow there. Tile drains historically were currently found in the East Branch watershed. A used in areas with hydric soils to make land suitable for farming. When tile drains are combination of biological, physical, and chemical broken, wetland hydrology may be able to be variables such as climate, drainage patterns, restored, providing opportunities for wetland vegetation, and topography have all interacted restoration/enhancement and stormwater together to form the soils found today. storage. Historic native vegetation in these areas consisted of water tolerant grasses, forbs, trees 4.4.1. Soil Series and shrubs. Soils are identified by a name associated with each
29
4. Watershed Characteristics Assessment series or class of soils with similar characteristics. A soil series is commonly derived from a town or landmark in or near the areas where the soil series was first identified (type location), although sometimes naming conventions vary by county or state. Soil series are differentiated based on the amounts and size of particles making up the soil (soil texture), water-holding capacity, the slopes where they are located, permeability characteristics, and organic content. Table 4-3 lists the dominant soil series located within the East Branch watershed. Exhibit 6 shows the locations of the dominant soil series located within the East Branch watershed.
30
4. Watershed Characteristics Assessment
Table 4-3 Soil Series in the East Branch DuPage River Watershed (DuPage County portion)
Soil Soil % of Soil Name Hydric? Erosivity Acres Code Group Watershed 805B Orthents, clayey, undulating No Moderate D 10537.81 21.90% 854B Markham-Ashkum-Beecher No Moderate C/D 9698.23 20.16% complex, 1 to 6 percent slopes 232A Ashkum silty clay loam, 0 to 2 Yes Moderate C/D 3782.02 7.86% percent slopes 531B Markham silt loam, 2 to 4 No Moderate C 3642.21 7.57% percent slopes 530B Ozaukee silt loam, 2 to 4 No High C 1954.78 4.06% percent slopes 531C2 Markham silt loam, 4 to 6 No Moderate C 1912.69 3.98% percent slopes, eroded 530C2 Ozaukee silt loam, 4 to 6 No High C 1823.97 3.79% percent slopes, eroded 3107A Sawmill silty clay loam, 0 to 2 percent slopes, frequently Yes Moderate B/D 1762.10 3.66% flooded 530D2 Ozaukee silt loam, 6 to 12 No High C 1455.14 3.02% percent slopes, eroded 146A Elliott silt loam, 0 to 2 percent No Moderate C/D 1336.46 2.78% slopes 223B Varna silt loam, 2 to 4 percent No Moderate C 1116.78 2.32% slopes 330A Peotone silty clay loam, 0 to 2 No Moderate C/D 853.89 1.77% percent slopes 298A Beecher silt loam, 0 to 2 No Moderate D 848.18 1.76% percent slopes W Water - - C 828.33 1.72% 802B Orthents, loamy, undulating No Moderate B 737.16 1.53% 369B Waupecan silt loam, 2 to 4 No Moderate C/D 637.66 1.33% percent slopes 69A Milford silty clay loam, 0 to 2 Yes Moderate B/D 398.88 0.83% percent slopes 526A Grundelein silt loam, 0 to 2 No Moderate C/D 386.48 0.80% percent slopes 189A Martinton silt loam, 0 to 2 No Moderate C/D 383.64 0.80% percent slopes 903A Muskego and Houghton mucks, Yes Moderate B 300.93 0.63% 0 to 2 percent slopes 327B Fox silt loam, 2 to 4 percent No High B 298.93 0.62% slopes 792B Bowes silt loam, 2 to 4 percent No Moderate D 265.35 0.55% slopes
There are 57 soil series found in the watershed; the majority are well drained, non-hydric soils. Native plant communities in the watershed were likely comprised of prairie grasses, forest, woodlands, and savannas. Of these 57, 22 are considered dominant soil types (greater than 0.5% of the watershed). The remaining 27 soil types have been classified as “non-dominant soils.” The “non-dominant” soils cover 6.55% of the East Branch DuPage River subwatershed. 31
4. Watershed Characteristics Assessment
Orthents, clayey, undulating is the predominant soil type in the watershed, covering 10,537.8 acres or approximately 21.9% of the watershed. Orthents indicates that it is a made-land or man-altered soil not resembling any specific native soil series. The Markham-Ashkum-Beecher complex is the next most dominant soil series covering approximately 20.16% or 9,698.23 acres of the watershed.
4.4.2. Hydric Soils Hydric soils are defined by the National Technical Committee for Hydric Soils (NTCHS) as soils that are formed under conditions of saturation, flooding, or ponding and retain moisture long enough during the growing season to develop anaerobic (oxygen-deprived) conditions in the soil layers closest to the surface. Table 4-4 identifies the percent coverage of hydric soils in each subwatershed and Exhibit 7 displays the coverage of hydric soils.
Table 4-4 Percent Coverage of hydric and non-hydric soils in the East Branch
Soil Category Total area (acres) Percentage of Watershed Non-Hydric Soils 40,476 85% Hydric Soils 7,655 15% Total 48,131 100%
4.4.3. Soil Erodibility Soil erosion and sedimentation are significant causes of degraded water quality throughout Illinois, and in the East Branch watershed. Soil erosion is the process in which soil is detached and moved by flowing water, wave action or wind. Through erosion, sediment is transported from its original location and deposited in a new location such as a stream, river, lake, or other ground surface. This deposition process, commonly referred to as sedimentation, affects surface water quality chemically, biologically, and physically.
Damage from sediment can be expensive both environmentally and economically. Over time, sediment deposits can blanket rock, cobble, and sandy substrate needed by fish and macroinvertebrates for habitat, food, and reproduction; reduce useful storage volumes in ponds, reservoirs, and lakes; and increase the need for costly water filtration systems for municipal drinking water supplies. Often, the impacts of erosion and sedimentation are additive and the effects and costs of the sedimentation can be severe, both for those immediately affected and for those who must mitigate subsequent problems.
A map identifying the highly erodible soils in the East Branch watershed was created (Exhibit 8) by selecting soils that have been classified as highly erodible by the NRCS. The maps of these soil groups indicates those areas that have the highest potential to degrade water quality when erosion and sedimentation occurs, and as such, that require special consideration for land use and stormwater management. In addition to identifying the locations of these highly erodible soil areas, it is also important to note that all of the remaining dominant soils in each of the three subwatersheds are considered moderately erodible soils.
32
4. Watershed Characteristics Assessment
Table 4-5 Highly erodible soils in the East Branch DuPage River Watershed
Soil Name Soil Code Acres Percent of Watershed Area Del Rey silt loam, 0 to 2 percent slopes 192A 32.37 0.07% Warsaw silt loam, 4 to 6 percent slopes, eroded 290C2 44.39 0.09% Fox silt loam, 4 to 6 percent slopes, eroded 327C2 65.54 0.14% Ozaukee silt loam, 2 to 4 percent slopes 530B 1954.78 4.06% Ozaukee silt loam, 4 to 6 percent slopes, eroded 530C2 1823.97 3.79% Ozaukee silt loam, 6 to 12 percent slopes, eroded 530D2 1455.14 3.02% Ozaukee silt loam, 12 to 20 percent slopes 530E 75.78 0.16% Ozaukee silt loam, 20 to 30 percent slopes 530F 1.31 0.00% Zurich silt loam, 4 to 6 percent slopes, eroded 696C2 16.13 0.03% Total 5,469 11.36%
4.4.4. Soil Infiltration Capacities (Hydrologic Soil Groups) The permeability and surface runoff potential of the soils in the United States have been classified by the NRCS into Hydrologic Soil Groups (HSGs). HSGs are based on a soil’s infiltration and transmission (or permeability) rates. The combination of HSG classification and land cover type (i.e. mowed lawn, rooftop, or forested area) is used by engineers to estimate runoff curve numbers, or how much stormwater is anticipated to flow off of a certain type of land area instead of percolating into the soil. This in turn affects the design and size of stormwater treatment systems for different development settings.
HSGs are classified into four primary categories: A, B, C, and D, and three dual classes, A/D, B/D, and C/D:
• Group A is comprised of the most permeable soil types and has the lowest runoff potential. These soils consist of mainly deep, well drained to excessively drained sands or gravelly sands. Group A soils have a high rate of water transmission. • Group B soils have a moderate infiltration rate and are moderately deep, moderately well drained or well drained with fine texture to moderately course texture (silt and sand). Group B soils have a moderate rate of water transmission. • Group C soils have slow infiltration rates because of a fine texture soil layer comprised of silt and clay that impedes the downward migration of water. Group C soils have a slow rate of water transmission. • Group D soils have the slowest infiltration rates and a high runoff potential. These soils are typically clay and exhibit very slow rates of water transmission. • Dual hydrologic groups (A/D, B/D, and C/D) are classified differently. The first letter represents the HSGs for the artificially drained soils in the area. The second letter represents the HSGs for the undrained, natural conditions. Only soils that are Group D in the natural conditions are assigned to dual classes.
Table 4-6 summarizes the HSGs and their corresponding attributes and Table 4-7 identifies the acreage and percent of the watershed for each HSG. In summary, 36.7% of the soils in the East Branch DuPage River watershed are Group C with 28.59% classified as Group B/D and 24.15%
33
4. Watershed Characteristics Assessment
classified as C/D. The remaining 10.56% of soils are comprised of Group A, B, D, and unclassified soils. There are no Group A/D soils in the East Branch DuPage River watershed.
Exhibit 9 shows the locations of various soils groups within the watershed. Along with understanding locations of hydric soils, identifying the location of Type A and B soils, and Type B/D soils, is imperative to a watershed planning process. Type A and B soils provide the greatest opportunity to infiltrate stormwater that could otherwise lead to overland transport of pollutants, erosion, and localized flooding. Many of the recommended actions in a watershed plan will include infiltration BMPs such as rain gardens, bioswales, and infiltration basins, which are best suited in Group A and Group B soil areas. However these areas comprise only 8.8% of the East Branch watershed’s area, making identification of these areas especially important.
Another 28.59% of the soils in the watershed are classified as B/D soils. Type B/D soils are soils with a water table within 24 inches of the surface. When adequately drained, Type B/D soils exhibit properties of Type B soils; however, in undrained conditions, Type B/D soils exhibit the properties of Type D soil and have a very high runoff potential when thoroughly wet. This requires very specific design considerations, engineering and planning for BMPs or flood control practices in these areas, but the predominance of these Type B/D soils in the East Branch DuPage River watershed should facilitate infiltration in pervious areas if proper design considerations are followed.
Table 4-6 Hydrologic Soil Groups and corresponding attributes in the East Branch DuPage River Watershed (DuPage County portion)
HSG Soil Texture Drainage Description Runoff Infiltration Transmission Potential Rate Rate A Sand, loamy sand, or Well to excessively well drained Low High High sandy loam A/D Sand or silt loam to Well drained to poorly drained High to High to High to Very clay Low Very Low Low B Silt loam or loam Moderately well to well drained Moderate Moderate Moderate B/D Silt loam, silty clay Moderately well to poorly Moderate Moderate to Moderate to loam, clay drained to Low Low Very Low C Sandy clay loam Somewhat poorly drained High Low Low C/D Sandy clay loam, Somewhat poorly drained to High Low to Very Low to Very silty clay loam, clay poorly drained Low Low D Clay loam, silty clay Poorly drained High Very Low Very Low loam, sandy clay loam, silty clay, clay
Table 4-7 Hydrologic Soil Groups including acreage and percent of watershed
HSG Total Acreage Percent of Watershed A 1,479 3.07% A/D 0 0.00% B 2,757 5.73% B/D 13,758 28.59% C 17,657 36.70% 34
4. Watershed Characteristics Assessment
C/D 11,619 24.15% D 1,479 3.07% Unclassified 845 1.76%
4.5. Cultural Resources Cultural resources are sites, structures, buildings, landscapes, districts, and objects that are significant in history, prehistory, archeology, architecture, engineering, and/or culture. Knowing the cultural resources of a watershed provides information on changes that occurred in the landscape and help define information related to historical vegetative communities, climate change, wildlife populations, and historic uses of the land, which is particularly useful in assessing potential restoration sites. And, as cultural resources provide learning opportunities for the public, the preservation and protection of cultural resources from development and damage can support public education and outreach objectives as well.
In 1966, the National Historic Preservation Act was passed to manage and protect cultural resources by requiring Federal and State agencies to establish historic preservation programs to identify, evaluate, and protect important sites under their jurisdiction. The National Park Service administers the National Register of Historic Places and Historic Landmarks as part of the requirements of the National Historic Preservation Act. Properties in the Register include districts, sites, buildings, structures, and objects that are significant in American history, archeology, architecture, engineering, and culture, and are nominated for inclusion in the Register by governments, organizations, and individuals. Different criteria and limitations on alteration apply to Historic Places and Historic Landmarks, with Historic Landmarks receiving the highest level of legal protection from modification or damage.
There are twelve Historic Places/Districts on the National Register in the East Branch watershed (Table 4-8 and Exhibit 10). There are no sites within the watershed listed on the National Register of Historic Landmarks. At the state level, the Illinois Historical Preservation Agency (IHPA) preserves and protects public and private historical properties and library collections. A review of the IHPA Historic Architectural Resources Geographic Information System (HARGIS) (http://gis.hpa.state.il.us/hargis/) indicates there are no sites within the East Branch DuPage River watershed identified on the HARGIS site as Illinois Historic Sites or Monuments.
Table 4-8 National Register of Historic Places sites in the East Branch watershed
Site Name Address Certification Date Bloomingdale School--Village 108 E. Lake St. 10/28/1994 Hall Bloomingdale, Illinois Randecker's Hardware Store 112 S. Bloomingdale Rd. 10/28/1994 Bloomingdale, Illinois Avery Coonley School 1400 Maple Ave. 08/08/2007 Downers Grove, Illinois George Baker House 1 S. 500 Taylor Rd. 03/01/2010 Glen Ellyn Downtown North Main St., Crescent Blvd., & Pennsylvania Ave. 09/18/2013 Historic District Glen Ellyn, Illinois Glen Ellyn Downtown South Main & Duane Sts., Hillside Ave. 09/18/2013 35
4. Watershed Characteristics Assessment
Site Name Address Certification Date Historic District Glen Ellyn, Illinois Glen Ellyn Main Street Historic Main St. btwn Cottage Ave. and Hawthorne St. Glen 10/29/1984 District Ellyn, Illinois Alfred A. Schiller House 734 Lenox Rd. 09/03/2008 Glen Ellyn, Illinois Stacy's Tavern Geneva Rd. and Main St. 10/29/1974 Glen Ellyn, Illinois DuPage Theatre and DuPage 101--109 S. Main St. 11/20/1987 Shoppes Lombard, Illinois First Church of Lombard Maple and Main Sts. 08/10/1978 Lombard, Illinois Adams Memorial Library 9th St. 06/04/1981 Wheaton, Illinois
4.6. Natural Resources This section of the plan describes the natural resources found within the East Branch watershed, including natural areas, parks, recreational trails, plant and animal species, wetlands, and groundwater. Because natural areas provide a natural defense against the ecological, social and economic impacts of both urban runoff and flooding, this Section has a special focus on the watershed’s significant natural areas, open lands and preserves, including the Morton Arboretum and lands managed by the Forest Preserve District of DuPage County.
4.6.1. Illinois Natural Area Inventory Sites
The Illinois Natural Areas Inventory (INAI) provides Illinois Natural Areas Inventory (INAI) a set of information about high quality natural areas, Scale of Natural Area Quality: habitats of endangered species, and other significant natural features. Information from the INAI is used Cat. I=High quality natural community and natural community restorations to guide and support land acquisition and protection programs by all levels of government as well as by Cat. II= Specific suitable habitat for state- private landowners and conservation organizations. listed species or state-listed species relocations The original Illinois Natural Areas Inventory was Cat. III= State dictated Nature Preserves, carried out in 1975–78, and it has been maintained Land and Water Reserves, and Natural by the Illinois Department of Natural Resources Heritage Landmarks since then. On June 1, 2007, a statewide update of Cat. IV= Outstanding ecological features the INAI was begun. Its goal is to develop an updated inventory of the highest quality grasslands, Cat. V= Not used at this time woodlands, and wetlands, based on the current Cat. VI= Unusual concentrations of flora or condition of Illinois’ landscapes using the latest fauna and high quality streams scientific knowledge and technology. The INAI Update will systematically screen the entire state to find, describe, evaluate, classify, and map natural areas. There are eight INAI sites located within in the East Branch DuPage River watershed (Table 4-9). These sites provide either Category I (high quality natural community or restoration), Category II (specific suitable habitat for listed species or relocations), or Category 36
4. Watershed Characteristics Assessment
III (Nature Preserves, Reserves or Landmarks) natural areas benefits. From a watershed planning perspective, these areas require special protection from runoff and other potentially adverse modifications.
Table 4-9 INAI Sites located within East Branch DuPage River watershed
INAI Site Name Municipality Number Categories Acres Belmont Prairie Downers Grove 0526 I, III 25.7 Churchill Prairie Lombard 0524 II, III 100 East Branch Marsh Glendale Heights 1399 II 8.5 Herrick Lake Forest Preserve Naperville 1397 II 765.6 Lyman Woods Downers Grove 1471 II 97 Maple Grove Forest Preserve Downers Grove 0527 I, II 48.7 Morton Arboretum Lisle 0506 I 1,406.3 Swift Road Meadows Addison 1391 II 136
4.6.2. Parks, Forest Preserve Lands and Trails Permanently preserved and managed natural areas are an essential element of the watershed’s natural areas “green infrastructure” network, providing areas where natural hydrologic processes and pollution uptake can help offset the many impacts of urbanization. In many cases, parks and forest preserve lands that are inundated during floods provide natural storage and protection of other developed areas. Temporary flood storage can be built or structured on park sites without compromising public recreation uses or natural area quality.
The East Branch watershed’s preserved open spaces principally consist of three types: Municipal-owned and managed; Park District lands; the Forest Preserve of DuPage County’s lands; and the 1,700 acre Morton Arboretum (Table 4-10). Local park districts manage numerous natural areas and recreational parks located entirely or partially within the East Branch watershed. There are eighteen properties managed by the Forest Preserve District of DuPage County (FPDDC) located in the watershed as shown in Exhibit 11, along with more than 34 miles of recreational trails within these preserves. Table 4-10 below notes if the trail is currently connected to or proposed to be connected to a regional trail.
Table 4-10 Natural Areas and Recreational Parks in the East Branch DuPage
Municipal Park DuPage County Forest Miles of Existing/ Proposed District Lands Acres Preserve Lands Acres Trail Regional Segment? 53 Trails Estates 20.16 Broadview Slough 27.30 0 Addison 844.67 Churchill Woods 257.98 1 Bloomingdale 1522.48 Danada 797.00 8 Butterfield 1386.82 East Branch 519.46 2 Carol Stream 19.21 East Branch Riverway 127.61 0 Darien 303.22 Egermann Woods 69.69 1 Downers Grove 8994.26 Glen Oak 4.87 0 G E Countryside 567.51 Green Meadows 43.31 0 Glen Ellyn 5939.14 Greene Valley 1382.16 11 Lisle 5598.98 Herrick Lake 733.50 7 Lombard 3354.91 Hickory Grove 31.18 0 37
4. Watershed Characteristics Assessment
Naperville 683.90 Hidden Lake 390.17 2 Oak Brook 74.35 Hitchcock Woods 18.33 0 Warrenville 23.60 Lyman Woods 134.69 0 Westmont 1551.65 Maple Grove 79.94 1 Wheaton 3368.02 Swift Prairie 114.66 0 Woodridge 4016.96 Willowbrook 48.20 1 York Center 13.63 Total Park District 38,283 Total FPDDC 4,780 34 Morton Arboretum 1,700
4.6.2.1 The Morton Arboretum The Morton Arboretum is an internationally recognized nonprofit organization dedicated to the planting and conservation of trees. The Arboretum was founded in 1922 by Morton Salt magnate Joy Morton whose inspiration came from his father, J. Sterling Morton, the founder of Arbor Day in the United States. The Arboretum’s 1,700 acres of land hold more than 222,000 live plants representing nearly 4,300 taxa from around the world. Situated on the rolling Valparaiso moraine and bisected by the East Branch DuPage River, The Morton Arboretum is planned and planted to nurture and display trees and shrubs in environments conducive to their growth. The Arboretum offers extensive educational programming for all ages, conducts leading research on tree health and tree improvement, breeds and introduces hardy and disease- resistant trees and shrubs for distribution throughout the Midwest, and presents nature-related activities year-round for people of all ages and interests.
The Arboretum’s 1700 acres of land are bisected by the East Branch DuPage River and it lies centrally in the watershed. Thus it is a relatively large, non-public land holder central to the watershed, and located just north of one of the most impacted,most distressed areas of the watershed. The Arboretum grounds also include 14 ponds and lakes of varying sizes, numerous seasonal drainage features, and Willoway Brook flows through the west side of the Arboretum grounds before joining the East Branch DuPage River.
4.6.3. Threatened and Endangered Species The Illinois Endangered Species Protection Board was created by the passage of the Illinois Endangered Species Protection Act in 1972 and determines which plant and animal species are threatened or endangered (T&E) in the state. The Illinois Endangered Species Protection Board also advises the IDNR on means of conserving those species. State listed T&E species are designated “endangered” if a species is in danger of extinction as a “breeding” species in Illinois and is considered “threatened” if the species is likely to become an endangered species within the foreseeable future.
A Freedom of Information Act Request was submitted to the Illinois Natural Heritage Database for the location of all threatened and endangered species documented within the East Branch DuPage River watershed. This information will be incorporated into the watershed plan once received.
In addition, the federal Endangered Species Act (ESA) of 1973, as amended, provides protection for species considered federally endangered or threatened. The definitions of threatened and 38
4. Watershed Characteristics Assessment
endangered are the same as that provided above for the state act, but for federal designation they are considered endangered or threatened throughout their worldwide range, rather than only within the state. Many species are listed by states as endangered or threatened that are not considered such in neighboring states and do not rise to that level of protection federally. There are 8 species of plants and animals considered federally threatened, endangered or are candidates for such listing within DuPage County. Several of these are not likely present within the East Branch DuPage River watershed, but the U.S. Fish and Wildlife Service who administers the federal ESA, does not provide watershed or location-specific information. Under the state rules, all federally listed endangered and threatened species are also automatically considered state-listed.
4.6.4. Wetlands, Riparian Areas, and Potential Wetland Restoration Sites This section describes both wetlands and the riparian areas – whether upland or wetland - associated with Defining a “Wetland” the tributaries and mainstem of the East Branch Land areas that are inundated or DuPage River. saturated with water for prolonged durations of time and support Of the many natural resources and features in a vegetation typically found in saturated watershed, wetlands play perhaps the most significant soil conditions are considered role in supporting the health of the watershed. wetlands. Wetlands generally include Wetlands provide habitat for fish, wildlife and a variety swamps, bogs, marshes, ponds, streams, wet meadows and similar of plants. Wetlands are also important landscape areas. Three factors are used to features: By holding and slowly releasing flood water determine the presence of wetlands: and snow melt, wetlands recharge groundwater, recycle nutrients, and provide recreation and wildlife 1. Hydric Soils - Soils which present certain characteristics when saturated. viewing opportunities for residents. Wetlands and their buffers also provide the substrate for a complex 2. Hydrophytic vegetation – Plants web of organic and inorganic processes. The products which grow in water or saturated soils. of these ecosystems, which then flow downstream, are 3. Hydrology - Saturation of soils with crucial resources for a properly functioning riverine water ecosystem and riparian environment.
However, wetland areas, once prevalent within Illinois, have continued to decline in area and quality. The loss of wetlands contributes both to flooding, since the storage function of flood waters is lost, and to pollution, since valuable pollutant capture and uptake functions are lost. Wetland restoration, in areas where soil types, drainage and topography are suitable for re- establishing wetland plants, can be an important component of watershed restoration and flood resilience.
4.6.4.1 Riparian Areas In general, riparian areas can be defined as the ecosystems, vegetation, and habitats located along the banks of streams and rivers. When left as undeveloped or natural areas, the riparian areas of streams and their tributaries perform several important functions. A riparian area with soils and vegetation in a natural condition, and particularly an area with trees, forms an
39
4. Watershed Characteristics Assessment important buffer to reduce the amount of pollution, particularly nutrients and sediment, that reaches the river through over-land flows.
Some of the banks of the East Branch are highly incised and close to residential properties. Some of the areas are within open space but still show signs of degraded and unstabilized banks, heavy sedimentation and weedy species dominating the edges of the stream. Many of the areas are vegetated although the predominant vegetation in many portions of the river corridor is undesirable weedy or invasive species. A description of existing conditions of riparian area habitat within the East Branch DuPage River watershed is pending.
Riparian areas within DuPage County are protected under Article XII of the DCCSFPO. Under this protection use or development within the riparian area is limited or restricted to certain activities. However, specific definitions of the width and features of a riparian area vary by jurisdiction, and even within different stream segments. For example, DuPage County has defined riparian areas as those lands within the limits of the 100-year floodplain, but this area can be reduced to a minimum of 15 feet in some areas with documented limited functional value .
4.6.4.2 Historic and Existing Wetland Resources The NWI was established by According to an analysis of National Wetlands Inventory the US Fish and Wildlife (NWI)/DuPage County Wetland Survey, there are approximately Service (FWS) to conduct a 2,583 acres of wetlands existing in the East Branch watershed. nationwide inventory of U.S. Field inspections and wetland delineations were not utilized in wetlands to provide biologists and others with information on the preparation of these maps. Certain wetland habitats are not the distribution and type of included on their maps due to limitations of aerial wetlands to aid in conservation reconnaissance to properly identify these habitats as wetlands. efforts. The NWI maps are Wetlands are shown in Exhibit 12. Additional information has prepared from the analysis of been requested on the DCS. high altitude imagery, vegetation, visible hydrology, and geography. As with most of the DuPage County area, wetlands in East Branch DuPage River watershed were relatively intact until European settlers began to alter significant portions of the watershed’s natural hydrology and wetland processes for the rich agricultural resources. According to data compiled by DuPage County, as shown in Table 4-11, comparing hydric soils from the Soil Survey data (81,737 acres) to the most updated NWI/DuPage County wetland inventory (15,256 acres of wetlands), DuPage County as a whole has experienced a loss of roughly 81 percent of its wetlands since pre- settlement times. A similar reduction in wetlands can also been seen within the East Branch DuPage River watershed as the watershed has lost approximately 85.9% of its wetlands since pre-settlement times (15,724 acres of historical areas to 2,583 existing wetlands).
40
4. Watershed Characteristics Assessment
Table 4-11 Historic and Existing Wetland Area, East Branch Watershed and DuPage County
Historic (acres) Existing (acres) Change Acres Percent East Branch 15,724 2,583 13,141 -84% Watershed DuPage County 81,737 15,256 66,481 -81%
Historic wetlands loss is largely attributed to physical alterations made through the removal or addition of material such as dredging, filling, or draining. These impacts were sometimes regulated through the federal and state wetland permitting process; however, even with additional regulations many wetlands remain susceptible to indirect impacts, such as those caused by uncontrolled stormwater discharges from upstream development. Altered hydrology, increased pollutant loadings, and buffer encroachment caused by urbanization often promote the spread of invasive species, reduce native habitat and vital ecosystem processes and increase sediment deposition.
4.6.4.3 Regulatory Policies and Protections Recognizing the damage caused by wetland loss and unregulated discharges, DuPage County implemented one of the most restrictive ordinances in the region. The DCCSFPO not only requires avoidance and/or minimization of wetland impact but also had some of the most stringent wetland mitigation requirements. The resolution of the County to administer this DCCSFPO also brought recognition from federal and state partners. This trust in the County’s regulations and ability to administer the DCCSFPO forged a partnership with the United States Army Corps of Engineers (USACE) for authorization of a General Permit 25 (GP25). This agreement gives the County review authority on behalf of the USACE for developments that could potentially affect wetlands. DuPage County was the only county in the region to receive this delegation which was originally granted in 1993 and reauthorized most recently in 2014. Additionally, the Illinois Environmental Protection Agency (IEPA) has also granted the County 401 Water Quality Certification as part of that GP25. Together these agency partnerships will help promote resource protection, reduce duplication of permitting efforts and provide better watershed decision making tools at the local level.
4.6.4.4 Wetland Restoration Wetland restoration and creation has the potential to improve flood resilience and water quality in the East Branch watershed. By restoring the environmental functions of degraded wetlands or creating new wetlands in suitable areas, wetland restoration and wetland creation could potentially reduce flood volumes and rates, increase plant and animal diversity, and improve water quality conditions.
Potential restoration sites within the watershed were identified using a Geographic Information System (GIS) exercise. As part of this exercise, an initial criterion of 10 acre parcels with hydric soils was utilized. This identified 789 potential wetland restoration sites (17,707.6 acres) within
41
4. Watershed Characteristics Assessment the watershed. Additional criteria and a rating scale were then used to better identify potential wetland sites. The scoring system, with a maximum value of 5, is based on five criteria:
• Hydric Soil Order: Histosol (organic hydric soils e.g. peats and mucks) were given preference to Mollisol (cumulic mineral hydric soils) as Histosol soils are known to respond better to restoration than Mollisol soils. Histosol soils tend to be easier to rehydrate as they are typically wet and provide better soils for wetland plant establishment. Histosol soils were assigned a 1 on the rating scale and Mollisol soils were assigned a 0. • Riparian adjacency: Preference was given to sites that were located immediately adjacent to a stream or ditch. Sites located immediately adjacent to a stream or ditch were assigned a 1 on the rating scale. • Riparian proximity (within 1,000 feet): Preference was given to sites that were located within 1,000 feet of a stream or ditch. Sites located within 1,000 feet of a stream or ditch were assigned a 1 on the rating scale. • Floodplain: Preference was given to sites that were located within the 100-year floodplain. Sites located within the 100-year floodplain were assigned a 1 on the rating scale. • Adjacent to advance idendification (ADID) or NWI wetlands: Preference was given to sites located immediately adjacent to ADID or NWI wetlands. Sites located immediately adjacent to an ADID or NWI wetland were assigned a 1 on the rating scale.
Analysis is ongoing. 4.7. Groundwater Resources Residents in the East Branch DuPage River Watershed utilize groundwater for a variety of purposes including drinking water, irrigation, and industrial process water. While under natural undisturbed conditions, groundwater in the East Branch DuPage River Watershed is of high quality and meets the drinking and groundwater standards set for different contaminants by the Illinois Pollution Control Board. Due to the nature of the aquifers in the region, impacts associated with urbanization have the potential to negatively impact drinking and groundwater. Potential sources for contamination associated with urbanization include septic system effluent, oil, gasoline, animal wastes, industrial effluent, paint, solvents, road salt, and lawn and household chemicals. The Chicago Metropolitan Agency for Planning’s “Go to 2040” regional comprehensive plan makes numerous recommendations regarding water resource conservation, including Integrated Land Use Policies and Site Planning with Water Resources, where it is stated, “[Land use policies that encourage compact development] should be coupled with the identification of sensitive aquifer recharge areas (SARAs) and their protection from potential contamination, which will help ensure the security of water supplies for future generations.”
Groundwater supplies in DuPage County are withdrawn from four principal geohydrologic units: 1) glacial drift aquifers, 2) Silurian dolomite aquifer, 3) Cambrian-Ordovician aquifer, and 4) the Mt. Simon aquifer. The glacial drift and Silurian dolomite aquifers receive recharge
42
4. Watershed Characteristics Assessment chiefly from precipitation that falls within the county limits. Relatively impermeable shales of the Maquoketa Formation separate these aquifers from the deeper Cambrian-Ordovician aquifer. Recharge to the Cambrian-Ordovician aquifer occurs in the areas of Kane, McHenry, Kendall, Boone, and DeKalb Counties where the Maquoketa Formation is appreciably dolomitic, relatively thin, or absent. The water moves southeastward from these recharge areas through the aquifer toward a deep cone of depression centered near Summit in Cook County.
In order to protect groundwater in Illinois in 1987, the General Assembly passed the Illinois Groundwater Protection Act (IGPA). The IGPA emphasizes the comprehensive management of groundwater resources by requiring the implementation of practices and policies to protect groundwater. These include implementing groundwater protection policies such as setback zones; assessing the quality and quantity of groundwater resources being utilized; and establishing groundwater standards.
Groundwater resource protection is an integral component of the East Branch DuPage River watershed planning process. As regulatory requirements favoring the infiltration of stormwater become more commonplace, it is imperative that proper knowledge exists regarding the location and condition of recharge aquifers and public water supply areas that could be threatened by stormwater management activities. However, infiltration of runoff from certain land uses is not necessarily desired in areas of groundwater recharge for community water system and private wells.
While watershed plans are to identify groundwater recharge areas within the watershed, at this time, there is not sufficient detailed technical information readily available to provide such information. DuPage County Department of Stormwater Management has sought technical assistance in identifying sensitive aquifer recharge areas within the county so that the information can be utilized to discourage activities that would facilitate the transport of soluble contaminants in these areas. However, at this time these technical assistance requests have not been granted. Outputs of such assistance could include a technical document detailing an overview of this topic and providing clarification regarding the requirements of applicable legislation (Illinois Groundwater Protection Act, Section 17.3 of the Illinois Environmental Protection Act, and 35 Illinois Administrative Code 620); review of available data (IEPA, DuPage County Health Department, Illinois State Geological Survey , or other sources); development of geospatial information; and/or other appropriate materials. 4.8. Agricultural Best Management Practices While the agricultural land area in DuPage County has declined as the County’s population and economic development have evolved, there are areas within the watershed with remaining agricultural lands that could, potentially, contribute both important natural and open space functions for the watershed, but also overland transport of pollutants and sediment. Various programs sponsored by the NRCS and Farm Service Agency Wetlands Reserve Program (WRP), Grasslands Reserve Program (GRP), Wildlife Habitat Incentive Program (WHIP), Environmental Quality Incentives Program (EQIP), Conservation Reserve Enhancement
43
4. Watershed Characteristics Assessment
Program (CREP), and Conservation Reserve Program (CRP) promote and fund the construction of agricultural BMPs on farmland.
Per the requirements of Section 1619, b, 4, B of the Farm Bill, the NRCS state office in Champaign, Illinois is only able to provide the number of contracts and the obligation amount by County for following programs: WRP, GRP, WHIP, and EQIP. A Freedom of Information Request (FOIA) for this information has been submitted to the NRCS. 4.9. Watershed Drainage, Hydrology & Hydraulics 4.9.1. Stream Flow, Discharge & Baseflow Characteristics The dynamics of any river system are best managed and understood with data from stream gauges, which determine the rate of flow (in cubic feet per second, or CFS) and height above or below flood stage of a surface water at a certain point. Stream gauge data also allows modeling of how a river will respond to precipitation events, by coupling stream gauge data with precipitation and temperature data.
4.9.1.1 Stream Gauges There are three active United States Geological Survey (USGS) gauging stations in the East Branch DuPage River watershed, and six more stations that were active historically.
Table 4-12 Active and historic stream gauges in the East Branch DuPage River watershed
USGS DuPage County Stream Gauge Location Period of Identification Identification Number Record Number Active Gauges 05540160 SG7 East Branch DuPage River near Active Downers Grove 05540195 SG8 St Joseph Creek at Route 34 at Active Lisle 05540250 SG9 East Branch DuPage River at Active Bolingbrook Historic Gauges 05510140 East Branch DuPage 1961 to 1979 River near Bloomingdale 05540150 East Branch DuPage 1961, 1963 to 1976, 1978-1980 River at Glen Ellyn 05540180 St Joseph Creek at Route Not available 34 at Lisle 05540200 St Joseph Creek at Route 1985 to 1990 34 at Lisle 05540220 Rott Creek near Lisle Not available 05540240 Prentiss Creek near Lisle 1961 to 1980
4.9.1.2 Flow Characteristics Historic low and mean flows are currently being analyzed.
44
4. Watershed Characteristics Assessment
Table 4-13 Historic Low and Mean Flows in the East Branch DuPage River watershed
Location 7-Day 10-Year Harmonic Mean Low Flow (cfs) Flow (cfs) Crescent Boulevard 4.0 13 Above Glenbard Wastewater 3.6 33 Authority – Glenbard Below Downers Grove Sanitary 23.6 54 District Above Woodridge 25.6 61 Before confluence 38.0 78
During summer-fall base flow, the East Branch is largely an effluent dominated river (Midwest Biodiversity Institute, 2014). Using the USGS gauge at Bolingbrook for September 2011, the median daily flow was 48 cfs while the average flow of 80.4 cfs was influenced by storms late in the month. From records of average daily flows from wastewater treatment plans (WWTPs) that discharge to the river upstream from the gauge, it appears that the average effluent discharge is 30.445 million gallons per day (MGD), or 56.6 cfs. This represents 98.1% of the median flow of 48 cfs recorded September 2011. While there is variability in effluent flow over this period, it is clear that during summer low flow periods, wastewater effluent is a dominant portion of the river’s base flow.
4.9.2. Channel Conditions The physical structure of the main stream channel of the East Branch River provides important information on the stream’s health and condition. The two most important processes are hydrologic modification or “hydromodification,” and channelization, as discussed below.
4.9.2.1 Hydromodifications Hydromodification describes how human activities change the dynamics of surface or subsurface flow in a river or stream. Historically, draining wetlands and channelizing or “ditching” streams to drain agricultural fields was the most common form of hydromodification. Early settlers of the Midwest quickly realized that the soils found under wetlands and wet prairies were ideal for crop production once dried, and installed sub-surface drainage tiles to re- route the water away from the wetlands and wet prairies and into ditches or streams. Since drain tiles work with gravity flow, receiving streams were excavated to a deeper depth and straightened to facilitate quicker drainage. This approach led to significant modification of the watershed’s original drainage patterns and wetland cover.
More recently, hydromodification has occurred throughout the East Branch watershed as a result of urbanization, which alters watershed hydrology and sediment-transport patterns. Development increases the amount of impervious surfaces (parking lots, rooftops, highly compacted ground, etc.) on formerly undeveloped landscapes. As a result, a larger percentage of rainfall becomes runoff during any given storm. Subsequently, runoff reaches stream channels much more quickly, and peak discharge rates and volumes are higher than before development for the same size rainfall event. The short-term impact result of this type of hydromodification is localized, overbank flooding, which is a persistent problem in the East Branch watershed. 45
4. Watershed Characteristics Assessment
Over the long term, hydromodification causes a stream channel to expand as a means of handling these higher storm flows. As the stream channel expands, banks will erode and the bottom of a channel will become deeper, a process called incision or downcutting. Incision releases significant amounts of sediment into the stream. Sediment in stream flow acts an abrasive on downstream banks, causing further erosion or scouring, and ultimately all of the released sediment is deposited into other portions of the stream, affecting aquatic life and habitat. Channel incision also leads to a disconnect between the stream and its floodplain. Once separated, high flows that were once stored in the floodplain and slowly released back into the stream are forced to remain in the channel. These “trapped” flows have high velocities, leading to additional streambank erosion and incision of the stream channel. This becomes a self-reinforcing cycle. With each rainfall event, a stream continues to erode, adding additional sediments to the watershed and further preventing the stream from accessing its floodplain.
4.9.2.2 Channelization Channelization is the practice of dredging and straightening stream channels to increase flow rates and carrying capacities (conveyance). In some cases, the stream channel will be paved with concrete during channelization or placed within underground pipes. Traditionally, channelization was done to move as much water as possible away from an area in a short period of time and prevent flooding. However, there are problems resulting from channelization. Channelization is detrimental for the health of streams and rivers through the elimination of suitable instream habitat for fish and wildlife and the creation of excessive flows in the stream leading to hydromodification both within and downstream of the channelized areas. In addition, this approach treats water as a waste product and leads to heightened water shortages within these aquatic systems during drought when water becomes a precious resource.
4.9.3. Hydraulic Structures Hydraulic structures are categorized as bridges, culverts, levees, weirs, dams, fencing and any other human made structures located in or over the stream channel. The location and condition of hydraulic structures is a valuable piece of information as hydraulic structures may act as possible constrictions in conveying river flow, increase the potential for backwater flooding problems, and impede the movement of fish and other aquatic species up and down the stream. A hydraulic structure inventory was not conducted as part of the watershed planning process.
4.9.3.1 Dams Dams create barriers to the movement and dispersal of aquatic organisms such as fish and may limit available habitat for breeding and feeding. There are currently three dams in the watershed; the Churchill Woods dam was removed in February of 2011 (see Table 4-14).
Table 4-14 Dams in the East Branch watershed
Dam Name Waterway River Impoundment Impedes Fish Mile Size (acres) Passage? West Lake Dam East Branch 26.8 13 Yes Maryknoll Gabion Weir East Branch 16.8 None No Prentiss Creek flow-through Dam Prentiss Creek/ East 0.1/8.6 N/A Yes Branch
46
4. Watershed Characteristics Assessment
Dam Name Waterway River Impoundment Impedes Fish Mile Size (acres) Passage? Churchill Woods Dam (removed 2/2011) East Branch 18.7 12 n/a
West Lake Dam
The West Lake Dam is locate at West Lake Park in Bloomingdale, Illinois and is situated approximately 0.5 miles north of Army Trail Road and 500 feet west of Glen Ellyn Road. The existing concrete inlet and outlet channels, and the existing lake outfall structure were constructed in the early 1970’s in conjunction with the development of the Westlake Subdivision. The primary function of the impoundment is to provide retention for excess stormwater runoff from the upstream Westland development. Additionally, the impoundment provides aesthetic and recreational uses as a public park operated and owned by the Bloomingdale Park District. The maintenance required to retain the impoundments function as a stormwater retention facility is handled by the Village of Bloomingdale.
Maryknoll Gabion Weir Dam
The Maryknoll gabion weir dam is located on the East Branch DuPage River adjacent to the Maryknoll subdivision in Glen Ellyn and is situated east of Maryknoll Circle, approximately ¼ mile south of Illinois State Route 38 (Roosevelt Road) and 200 feet west of I-355. The dam was constructed in the early 1980’s as part of the Maryknoll Development to provide stormwater detention for the development. Flow at normal water level is not impeded. The dam consists of gabions with no concrete caps. The impoundment does not extend further upstream than Illinois State Route 38.
Prentiss Creek Dam (flow-through)
The Prentiss Creek Dam is located on the East Branch DuPage River within the Seven Bridges Golf Club in Woodridge, Illinois. The dam actually consists of two structures, one on the East Branch DuPage River and one at the mouth of Prentiss Creek, both located upstream of Hobson Road. The structures are owned by the Village of Woodridge and were constructed in 1989 to provide online stormwater detention for the adjacent development. The dams are gravity structures consisting of rock-filled gabions that impound water at a greater rate as the flow rate increases. The East Branch DuPage River is 20 feet wide and the Prentiss Creek structure is 10 feet wide.
Churchill Woods Dam
The Churchill Woods Dam was located on the East Branch DuPage River within the Churchill Woods Forest Preserve in Glen Ellyn, Illinois. The dam was originally built in the 1930’s as part of the Works Progress Administration. The dam was a 50-foot long and 3.5 feet high concrete gravity dam and created an impoundment that was approximately 31 acres in size that extended from Crescent Boulevard to approximately St. Charles Road. The dam was removed in February 2011, and this reach of the river has shown improvement in Dissolved Oxygen levels as a result
47
4. Watershed Characteristics Assessment
However, the river is still somewhat impounded at the site, with the new impoundment elevation set by three box culverts under Crescent Boulevard. The new impoundment is approximately 12 acres in size.
4.9.3.2 Levees One major levee system is located within the East Branch DuPage River watershed. The levee system is located along the East Branch DuPage River in Lisle. A levee is situated along the west bank of the East Branch DuPage River from just south of the I-88 Tollway ponds to the Burlington Northern Railroad. The levee on the east bank of the river is located from just south of the I-88 Tollway ponds to Maple Avenue. The levee system was built by the State Division of Waterways in the 1960s to protect the area from flooding. At that time, the levee was designed to give a 50-year level of protection but over time the levee has settled and eroded in several locations reducing the level of protection. In addition, development within the watershed had contributed to increase flow rates along the river, further reducing the level of protection.
4.9.3.3 Major Culverts Culverts are structures that allow water to flow under a road, railroad, trail, or similar obstructions. Culverts are typically made of concrete, galvanized steel, aluminum, or plastic, typically high density polyethylene and may be used to form a bridge-like structure to carry traffic. When culverts do not provide sufficient space for high flows, ponding or flooding on the upstream side can result, and scouring can result downstream as outflows are concentrated by the associated outlet. Re-sizing culverts, or replacing culverts with bridges or other structures with larger spans that allow high flows to pass, is an important watershed restoration and protection strategy. Table 4-15 identifies the major culverts in the East Branch DuPage River watershed.
Table 4-15 Major Culverts in the East Branch watershed
Identification Location Size Description/Comments Number East Branch DuPage River At 75th Street, Woodridge At Maple Avenue, Lisle At Ogden Avenue, Lisle At Warrenville Road, Lisle At Crescent Boulevard (Churchill Woods Forest Preserve), Glen Ellyn At Canadian National Railway, Glendale Heights St. Joseph Creek Downtown Downers Grove
4.9.4. Stormwater Management Facilities As DuPage County transitioned from agricultural uses to residential, industrial, commercial, and transportation land uses, the stormwater management structures and systems evolved from reliance on natural streams and ditches to an engineered system of storm drains. The goal of storm drain engineering until very recently was to remove stormwater runoff from the
48
4. Watershed Characteristics Assessment
developed areas to streams as quickly as possible. This resulted in rapidly changing or “flashy” hydrology, where the water level in streams rises quickly during storm events and then falls quickly once the storm passes. Without detaining or managing stormwater from developed areas, hydromodification – described in Section 4.9.2.1 above – rapidly occurs, leading to stream channel degradation such as downcutting and channel widening, as well as, flooding.
Over time, stormwater management and engineering shifted from a philosophy of rapid conveyance of water to streams, to the benefit of temporarily detaining stormwater runoff in detention basins, regional compensatory storage basins, or other stormwater management facilities, to the more recently developed “green infrastructure” or “Low Impact Development” approach that manages stormwater as close to its source as possible, using techniques that mimic the natural hydrologic processes of infiltration, evaporation or evapotranspiration by plants.
Throughout DuPage County and the East Branch watershed, there are flood control and detention structures constructed over time that have become an essential part of the watershed’s function and hydrology. The major types of structures and their implications are described below.
4.9.4.1 Detention Basins Detention basins or detention ponds are stormwater management facilities that are constructed on or adjacent to rivers, streams, or lakes that are designed to temporarily detain runoff in order to protect against flooding and protect downstream channels from hydromodification. Detention facilities that are constructed on a river or stream are commonly referred to as “on- line” basins. On-line basins are not recommended and are prohibited under a variety of stormwater regulations.
Detention basins that are not on-line are typically constructed in low areas relative to development and either discharge directly to a surface water or discharge to surface water through a stormsewer network. Detention basins are often designed to be dry, where no water is stored permanently, or wet, where a permanent pool of water is maintained. Dry detention basins typically hold water for short periods of time following rain events. They are commonly lined with manicured turf grass. While dry detention basins may slow water from reaching creeks and rivers, their short residence time does not promote groundwater infiltration, allow settling and removal of pollutants, or provide significant water quality benefits.
Wet basins are designed to retain some volume of water at all times. The amount of water is determined by the elevation of the outlet pipe of the basin. The sideslopes of wet basins can be planted with both turf grass or native grasses. Wet detention basins planted with native vegetation are commonly referred to as “naturalized” detention basins, and have an emergent zone planted with native plants, flowers, and shrubs. In addition to providing stormwater management, naturalized detention basins can promote groundwater infiltration and maximize the water quality benefits and wildlife habitat.
49
4. Watershed Characteristics Assessment
Retention basins can also be used for stormwater management. The difference between a retention basin and a detention basin is that a retention basin is designed to hold water on a more permanent basis. Water often remains indefinitely in a retention basin until it evaporates or infiltrates into the soil.
A detailed detention and/or retention basin inventory was not conducted as part of this watershed-based planning process. However, several local municipalities within the watershed have conducted detention basin inventories. Additionally, as DuPage County has had the DCCSFPO in place since the 1991, it is assumed that all development constructed since that time has met the respective stormwater management requirements that include provisions for detention and/or retention.
4.9.4.2 Compensatory Storage Facilities Under the DCCSFPO and state regulations, any fill placed within an active defined floodplain requires some measure of compensatory flood storage to offset the volume lost. Floodplains provide the functions of flood storage, natural habitat, and water quality. Placement of fill impairs these functions and should be avoided. Impacts of fill in the floodplain is particularly important in smaller watersheds which respond more quickly to changes in topography. In cases when placement of fill is necessary, compensatory storage can mitigate some of the negative impacts of floodplain fill. The developer is required to offset new fill put in the floodplain by excavating an additional floodable section of the floodplain to replace the lost storage volume. The difference between compensatory storage and a detention or retention basin is that the purpose of compensatory storage is to provide flood volume storage to replace storage lost due to fill placed in the flood plain and the purpose of a retention or detention basin is to reduce the peak rate of runoff to a stream or storm sewer. Usually referred to as comp- storage areas, there are five compensatory flood storage facilities located within the East Branch DuPage River watershed. The facilities and their storage basins are detailed in Table 4-16.
Table 4-16 Open Water Areas of the Compensatory Storage Facilities within the East Branch Watershed
Facility Location Approximate Area of Open Water (acres) Roosevelt and I-355 West of 355, near intersection of 355 and Roosevelt 37.2 Hidden Lake reservoir Southeast of intersection of IL Rt. 53 and IL Rt. 56 18.7 Corps East South of 88, just east of the East Branch DuPage 3.9 River Corps West South of 88, just west of the East Branch DuPage 3.7 River Four Lake South of Maple Ave, west of IL Rt. 53 and River 40 Bend Golf Club Seven Bridges North of Hobson Road and west of IL Rt. 53 28
4.10. Floodplains Floodplains are generically defined as low flat areas along streams and rivers that frequently flood when stream flows are high. In the DCCSFPO, a floodplain is defined as the area typically
50
4. Watershed Characteristics Assessment
adjacent to and including a body of water where ground surface elevations are at or below a specified flood elevation.
To address flooding and control water quality, the Federal Emergency Management Agency (FEMA) requires municipalities to perform floodplain mapping and develop management plans to receive federal flood insurance. This information is also relevant to water quality protection and restoration activities because floodplains, when inundated, serve many functions and provide important habitats for a variety of fish and wildlife. Floodplains are important for spawning and rearing areas. Floodplain wetlands act as nutrient and sediment sinks, which can improve water quality in streams. They also provide storage that can decrease the magnitude of floods downstream, which can benefit fish and landowners in riparian areas. In addition, streams that are actively connected to their floodplains are less prone to severe downcutting and erosion.
Overbank flooding as defined in Section 6.2.1.1, is critical issue for East Branch. Both urban (street) flooding from backup of drainage system, and overbank flooding, affecting multiple areas within the East Branch DuPage watershed, but four in particular are described below.
Current floodplains are shown in Exhibit 13. 4.11. Water Quality Water quality in the East Branch is affected by the Point sources of pollution are discharge of pollutants from both point and non-point discharges from a single, sources into the River. Storm drain and wastewater discrete source, such as a storm treatment plant outfalls are found throughout the drain or wastewater pipe watershed. During storms, pollutants on the landscape discharging into a river. are washed from the ground and impervious surfaces into storm sewers and roadside drainage ditches, and Non-point sources are ultimately into the East Branch DuPage River stream diffuse; non-point pollution system. Physical changes in the watershed, such as occurs primarily through over- hydromodification, channelization and the loss of land runoff from yards, rooftops, riparian vegetation and wetlands, also affect water quality roads, parking lots, and farm and aquatic habitat. fields reaching rivers and other surface waters. The causes and sources of water quality problems in the East Branch result principally from urbanization, rather than agricultural runoff (which affects many other Illinois watersheds). Pollutant sources and loads in the watershed are the result of many years of modification of the watershed landscape as it changed from natural to agricultural to urban, which have led to modification of the stream channel, encroachments in the floodplain, and the loss of wetlands. Other changes are the result of the increased watershed impervious cover that has led to an increase in the volume and rate of runoff in the watershed. The increased quantity of runoff has caused problems such as excessive stream bank erosion and the deepening of the stream channel due to channel erosion. In addition to increasing surface runoff, impervious surfaces reduce the amount of rainwater that infiltrates into the ground to recharge groundwater sources. 51
4. Watershed Characteristics Assessment
The urban environment has also introduced increased amounts of various pollutants into the watershed. Examples include increased chlorides from deicing salts used on roadways and sidewalks during winter storm events; nutrients from lawn fertilization, pesticides used in manicure landscapes, and industrial chemicals that may be accidentally released into the environment. Other chemicals and pollutants are introduced from household products that cannot be removed by current wastewater treatment technologies. These all add up to impact the water quality of the East Branch DuPage River.
4.11.1. State of Illinois Water Quality Reporting Surface water quality monitoring is used by limnologists and scientists to evaluate the ecological health of a waterbody. The overall objective for water quality sampling is to assess the existing conditions of a stream, river or lake in an attempt to restore or maintain the chemical, physical, and biological integrity of the monitored surface water. The surface water assessments included in the 2014 Illinois Integrated Water Quality Report and Section 303(d) List, which IEPA submits to the US EPA bi-annually pursuant to the federal Clean Water Act, are based on data obtained through chemical, physical, and biological sampling of the State’s waterways. The Integrated Report includes has four primary parts:
• A detailed description of the how the State assesses water quality, including the frequency of and parameters used in its monitoring program. • The designated uses established for each waterway, or those human uses and ecological functions that a waterway would be expected to provide, based on the waterway’s structure and setting. In Illinois, the “designated uses” for surface waters include aquatic life, indigenous aquatic life, fish consumption, primary contact, secondary contact, water supply and aesthetic quality. • A determination whether waterways do or do not meet the standards established for their designated uses – waterways not meeting the standards are designated as “fully supporting” or “not supporting” the use, and any water not supporting the use is considered “Impaired;” and • For any waterway designated as “impaired,” an identification of the types and sources of pollutants causing the impairment, and a priority ranking for the development of Total Maximum Daily Loads (TMDLs), or pollution budgets, by waterway or segment.
Priority for TMDLs in Illinois is based on the amount of information available to demonstrate that a designated use is not supported, and whether USEPA required that the assessed waters be placed into categories based on their attainment (Table 4-17). Category 5 waters – those for which available data indicate that designated use is not supported, a TMDL has not been prepared, the impairment is due to pollution, and controls on discharges are not likely to bring the water back into compliance – comprise the Illinois 303 (d) list.
52
4. Watershed Characteristics Assessment
Table 4-17 Categorization of 303(d) Listed Waters in Illinois
Category Sub- Description Category 1 All designated uses are assessed as fully supporting and no use is threatened (Note- Illinois does not assess any waters as threatened). 2 Available data and/or information indicate that some but not all designated uses are supported 3 Insufficient data and/or information to make a use support determine for any use 4 Waterbodies contain at least one impaired use but TMDL is not required. Category 4 is subdivided as listed below based on the reason a TMDL is not required. 4a TMDL has been approved or established by the USEPA. 4b Technology based effluent limitations required by the Clean Water Act, more stringent effluent limits required by the state, local, or federal authority, or other pollution control requirements required by state, local or federal authority are stringent enough to implement applicable water quality standards within a reasonable period of time 4c Failure to meet the applicable water quality standards is not caused but a pollutant but other types of pollution (such as aquatic life impairment due to habitat degradation) 5 Available data and/or information indicate that at least one designated use is impaired and a TMDL is required.
4.11.1.1 Impairments in the East Branch Watershed According to the 2014 Integrated Water Quality Report and Section 303(d) list, two streams located in the East Branch watershed are listed as impaired for one or more designated uses: The East Branch mainstem, and St. Joseph’s Creek. Details on the 2014 303(d) listing are provided in Table 4-18.
Table 4-18 2014 303(d) Listings in the East Branch Watershed
Stream Assessment Length Designated Use Cause of Impairment Priority Name ID of Reach St Joseph IL_GBLB-01 4.29 Aquatic Life Dissolved Oxygen, Oil and Low Creek Grease, Total Suspended Solids (TSS) East Branch IL_GBL-02 8.01 Aquatic Life Arsenic, Dissolved Oxygen, Low DuPage Methoxychlor, Phosphorus River (Total) Fish Consumption Polychlorinated biphenyl Low (PCBs) IL_GBL-05 3.18 Aquatic Life Phosphorus (Total), Total Low Suspended Solids (TSS) Fish Consumption PCBs Low IL_GBL-08 4.69 Aquatic Life Arsenic, Dieldrin, Low Hexachlorobenzene, Methoxychlor, pH, Phosphorus (Total), Sedimentation/Siltation, Total Suspended Solids (TSS) Fish Consumption PCBs Low IL_GBL-10 4.66 Aquatic Life Arsenic, Dieldrin, Low 53
4. Watershed Characteristics Assessment
Hexachlorobenzene, Methoxychlor, pH, Phosphorus (Total) Fish Consumption PCBs Low Primary Fecal Coliform Low Recreation IL_GBL-11 3.45 Aquatic Life Dissolved Oxygen, Low Phosphorus (Total) Fish Consumption PCBs Low 4.11.1.2 TMDLs in the East Branch Watershed Between 1992 and 1998, both Salt Creek and the East Branch DuPage River were listed on the Section 303(d) List of Impaired Waters by the State of Illinois. Total Maximum Daily Loads (TMDLs) for Salt Creek, the East Branch and St. Joseph’s Creek were been prepared by the State and approved by USEPA in October 2004 (Table 4-20).
Table 4-20 Approved TMDLs in the East Branch watershed
Stream Name Assessment ID Impairment TMDL Status TMDL Approval Addressed Date St. Joseph Creek IL_GBLB-01 Dissolved Oxygen Approved September 24, 2004 East Branch IL_GBL-05 Ammonia-N Approved September 24, DuPage River 2004 Carbonaceous Approved September 24, Oxygen Demand 2004 (CBOD) IL_GBL-08 Ammonia-N Approved September 24, 2004 CBOD Approved September 24, 2004 Excessive Algae Approved September 24, 2004 Dissolved Oxygen Approved September 24, 2004 IL_GBL-10 Ammonia-N Approved September 24, 2004 CBOD Approved September 24, 2004 Excessive Algae Approved September 24, 2004 Total dissolved Approved September 24, solids 2004 Chloride Approved September 24, 2004 Dissolved Oxygen Approved September 24, 2004 IL_GBL-05 Chloride Approved September 24, 2004 Total dissolved Approved September 24, solids 2004 Dissolved Oxygen Approved September 24, 2004
54
4. Watershed Characteristics Assessment
4.11.1.3 TMDL Implementation Requirements and Steps Each TMDL for the East Branch watershed was intended to provide a roadmap to reducing pollutant levels enough to achieve full compliance with Illinois water quality standards, and by extension to support the designated uses for each waterway. The chloride TMDL, for example, calls for a 33 percent reduction in overall chloride application within the East Branch watershed in order for the water quality standard for chloride (500 mg/L) to be met. Since the completion of the chloride TMDL, the DuPage River/Salt Creek Workgroup (DRSCW) has formed a Chloride Committee and the Chloride Usage Education and Reduction Program to develop and promote alternatives to conventional roadway deicing practices and guide the implementation of the alternatives.
Three allocation scenarios were developed for the dissolved oxygen (DO) TMDL. In the first scenario, point sources (chiefly wastewater treatment plants) would have to reduce their permitted load of CBOD5 (Carbonaceous biological oxygen demand 5 day test) and ammonia nitrogen. The scenario was intended to achieve CBOD5 limits of 8 mg/L and ammonia limits of 1 mg/L. In the second allocation scenario, point sources would remain at existing monthly average permit limits, but either the Churchill Woods dam was to be removed, or the water behind the dam artificially aerated in order to achieve the water quality target. Through efforts of the working group, DuPage County, and other collaborating agencies, the Churchill Woods dam was removed in February 2011. However, the river is still somewhat impounded at the site with the new impoundment elevation set by three box culverts under Crescent Boulevard. Additional studies are on-going to determine the impacts the dam removal has had on DO levels within the East Branch DuPage River.
4.11.2. IEPA Permit Programs The Illinois Environmental Protection Agency (IEPA) Bureau of Water regulates point-source discharges of water and wastes into the State’s surface waters through its implementation of the National Pollutant Discharge Elimination System (NPDES) program. This program was initiated under the Clean Water Act to reduce (and ultimately eliminate) the discharge of pollutants to surface waters. The NPDES program requires permits to be issued for the discharge of wastewater treatment plant effluent, treated industrial effluent, and stormwater from both municipal separate storm sewer systems (MS4s) and construction sites. The NPDES program is an important means that the State of Illinois has for implementing the goals and recommended actions in a watershed plan: Requirements or provisions in NPDES permits can compel actions that actively reduce pollutant loading and hydromodification, such as the construction of BMPs to treat wastewater and stormwater discharges, the effective maintenance of municipal systems and construction sites, and public education aimed at reducing non-point source pollutants.
4.11.2.1 NPDES Point Source Discharges for Wastewater, Combined Sewer Overflow and Industrial Effluent The point sources of effluent within the East Branch watershed, which are more easily identified and defined than non-point sources, are eight major wastewater treatment plants (WWTPs) in
55
4. Watershed Characteristics Assessment the watershed, the combined storm and sanitary sewer system in portions of the Village of Lombard, and three permitted discharges of treated industrial wastewater.
Lombard’s combined sewer system discharges a combination of stormwater and untreated wastewater known as a Combined Sewer Overflow (CSO) during heavy rain events when the WWTP cannot fully treat all of the influent reaching the plant. CSO reduction, a goal of this Plan, can be accomplished over time through the addition of stormwater storage, separation of storm and sanitary sewers, and construction of stormwater treatment BMPs that prevent stormwater from reaching the storm sewer system, such as permeable surfacing, green streets, or infiltration basins.
There are eight permitted WWTPs in the watershed discharging an average total of 52.77 million gallons per day (MGD) of treated wastewater into the East Branch itself (Table 4-21). Three industrial users, also listed in the table, likewise contribute discharges into the East Branch. Each WWTP must meet the treatment and pollutant load reduction requirements of its NPDES permit, which must be re-issued every five years and which may be modified to require more reductions through application of new technology or different operational practices. Wastewater treatment plants are, in fact, an important source of the base flow in the East Branch. During the summer-fall period (July through October), the volume of effluent exceeds the typical base flow in the river, making the East Branch an “effluent dominated” stream system during this period. The WWTP discharges and industrial discharges into the East Branch are quantified in Table 4-21 and shown in Exhibit 14.
Table 4-21 Wastewater Treatment Plants (WWTPs) and NPDES Industrial Discharges in the East Branch watershed
NPDES Facility Name Average Maximum Receiving Permit Flow Design Flow Stream Number (MGD) (MGD) Municipal WWTPs IL0021130 Bloomingdale – Reeves 3.45 8.625 East Branch IL0028967 Glendale Heights 5.26 10.52 Armitage Ditch IL0022741 Glenbard WW Authority – Lombard 58.0 East Branch IL0021547 Glenbard WW Authority-Glenbard 16.02 47.0 East Branch IL0028380 Downers Grove SD 11 22.0 East Branch IL0031844 DuPage Co. – Woodridge 12 28.6 East Branch IL0032689 Bolingbrook #1 2.04 4.51 East Branch IL0032735 Bolingbrook #2 3.0 7.5 East Branch Industrial Discharges IL0053155 Elmhurst Chicago Stone-Barber (Pit pumpage and stormwater) IL0065021 Blackhawk Molding Company (non-contact cooling water) IL0075426 Pepperidge Farm, Downers Grove (non-contact cooling water and cooling tower spillage)
56
4. Watershed Characteristics Assessment
4.11.2.2 NPDES Stormwater Regulations Stormwater runoff is a major source of point (MS4) and non-point source pollution loads in the East Branch watershed. Stormwater runoff includes rainwater and snow melt that flows off the land into storm sewers or directly into lakes, rivers, or streams. Stormwater runoff can carry a wide range of pollutants including sediment, nutrients, metals, chlorides, and petroleum. Additionally, as the runoff flows over land, it can lead to increased erosion of exposed soils, especially on construction sites.
The State’s implementation of stormwater regulations through the NPDES program began in the 1990s with the Phase I program, which required cities with populations over 100,000 to obtain an NPDES permit for their municipal separate storm sewer systems (MS4s). Phase I also required NPDES permits for certain industrial uses, and for construction sites disturbing 5 acres or more of land. The NPDES Phase II program, initiated in 2003, included additional smaller communities in the MS4 permit program, and decreased the threshold for a construction site permit to one acre or more of land disturbing activity.
All of the municipal jurisdictions in the East Branch watershed are now covered under the MS4 permit. The MS4 communities are required to complete a series of Best Management Practices (BMPs) and measurable goals for the six “minimum measures” of the permit program:
1. Public education and outreach on stormwater impacts; 2. Public involvement in water quality and watershed health; 3. Illicit discharge detection and elimination 4. Construction site stormwater runoff control 5. Post-construction stormwater runoff control in new developments exceeding minimum thresholds; and 6. Pollution prevention and “good housekeeping” for municipal operations.
In addition to the six control measures, the MS4s must also submit a Notice of Intent (NOI) and an annual report of activities related to the permit to the Illinois EPA.
4.11.2.3 NPDES Construction Permits NPDES Phase II stormwater regulations also address potential erosion from construction including commercial, residential, road building, and demolition sites in the state that disturb more than one acre of land. Each County and the municipalities in the East Branch watershed have in place soil erosion and sediment control ordinances that are aimed at reducing the potential for sediment from construction activities from negatively impacting the East Branch DuPage River watershed.
Land disturbance is defined as exposing soil during clearing, grading, or excavation. The regulations specifically require the operator (person with operational control of the day to day construction activities) of the property to ensure compliance with the permit conditions outlined in the Illinois Construction Site General Permit (ILR10). These requirements include submitting a Notice of Intent (NOI) to begin construction, create a Stormwater Pollution Prevent Plan (SWPPP) to control erosion during construction, and submit a Notice of
57
4. Watershed Characteristics Assessment
Termination (NOT) when the site is permanently stabilized. The regulations also require that the construction site be inspected every 7 days and after every 0.5-inch or greater rainfall event or equivalent snowfall by a qualified inspector. During the weekly inspection, existing soil erosion and sediment control (SESC) practices are inspected for needed repairs. Additionally, the inspections are used to identify additional potential sources of erosion and sedimentation and make recommendations for additional SESC control practices. If construction activities result in an off-site discharge of sediment bearing waters, the operator is required to submit an Incident of Non-compliance (ION) to the Illinois EPA and provide a plan to prevent further releases of sediment.
4.11.3. Water Quality Monitoring Stations, Results and Trends This data is in the process of being collated and analyzed and will include information provided by the IEPA, IDNR, DuPage County, The Conservation Foundation, and DuPage River Salt Creek Workgroup.
Typically, chemical and physical water quality monitoring includes the collection of water quality samples that are analyzed for the following parameters:
• Temperature • pH • Dissolved oxygen (DO) • Conductivity • Total suspended solids (TSS) • Metals including cadmium, chromium, copper, iron, lead, manganese, mercury, silver, and zinc • Nitrogen including nitrite, nitrate, and total nitrogen • Phosphorus including dissolved phosphorus and total phosphorus • Bacteria • Chlorides
Temperature
Water temperatures fluctuated with daily air temperatures as well as with seasonal changes, i.e., water temperatures are higher in summer and cooler in spring and fall. Maximum water temperatures over 20°C may preclude most fish from using these streams for habitat.
pH
Normal pH (a measure of hydrogen ions in the water) values in streams should range from 6.5 to 8.5, good conditions for aquatic life.
Dissolved Oxygen
Algae and aquatic plants in the creek elevate dissolved oxygen (DO) concentrations during the day (due to photosynthesis) and lower DO concentrations at night (due to respiration). Low DO conditions typically exist in mid to late summer when air and water temperatures are high and
58
4. Watershed Characteristics Assessment
water levels are low. DO concentrations below 5.0 mg/L can stress many fish species, and concentrations below 1.0 mg/L (hypoxic conditions) can be detrimental to aquatic life. The Illinois water quality standard for DO is detailed in the Table 4-22
Table 4-22 Illinois DO Water Quality Standard
Measurement Interval Water Quality Standard August-February March-July At any time 3.5 mg/L 5.0 mg/L 7 day average 4.5 mg/L Daily Min Average 6.0 mg/L Daily Min Average 30 day average 5.5 mg/L Daily Mean N/A
Conductivity
Specific conductivity indirectly measures the concentration of chemical ions or dissolved salts in the water, and may be an indicator of salt as a pollutant. The more chemical ions or dissolved salts a body of water contains, the higher the conductivity will be. Conductivity levels of 200- 1,000 µS/cm are indicative of normal background levels. Conductivity outside of this range may not be suitable for certain species of fish or bugs. High conductivity (1000 to 10,000 µS/cm) is an indicator of saline conditions. High chloride concentrations following salt applications for snow melting in winter can lead to high conductivity readings, as can the leaching of effluent from a sanitary sewer line into a stream. Low water levels tend to increase concentrations of ions in the water column, while rain events tended to temporarily flush ions out of the stream system.
Total Suspended Solids (TSS)
Total suspended solids (TSS) include all particles suspended in water which will not pass through a filter. Suspended solids are present in effluent from wastewater treatment plants and many types of industrial wastewater. There are also nonpoint sources of suspended solids, such as soil erosion from agricultural and construction sites.
As levels of TSS increase, a water body begins to lose its ability to support a diversity of aquatic life. Suspended solids absorb heat from sunlight, which increases water temperature and subsequently decreases levels of dissolved oxygen (warmer water holds less oxygen than cooler water). Photosynthesis also decreases, since less light penetrates the water. As less oxygen is produced by plants and algae, there is a further drop in dissolved oxygen levels.
TSS can also destroy fish habitat because suspended solids settle to the bottom and can eventually blanket the river bed. Suspended solids can smother the eggs of fish and aquatic insects, and can suffocate newly-hatched insect larvae. Suspended solids can also harm fish directly by clogging gills, reducing growth rates, and lowering resistance to disease. Changes to the aquatic environment may result in a diminished food sources, and increased difficulties in finding food. Natural movements and migrations of aquatic populations may be disrupted.
59
4. Watershed Characteristics Assessment
Metals
Additional discussion is being prepared.
Nitrogen
Nitrogen can be found in several different forms in terrestrial and aquatic ecosystems. These forms of nitrogen include ammonia (NH3), nitrates (NO3), and nitrites (NO2). Nitrogen is an essential plant nutrient, but in excess amounts it can cause significant water quality problems. Together with phosphorus, nitrogen in excess amounts can accelerate eutrophication, causing dramatic increases in aquatic plant growth (for example algae blooms) and changes in the types of plants and animals that live in stream and lakes. The increase in aquatic plant growth, in turn, affects dissolved oxygen (DO), temperature, and other indicators. Excess ammonia (NH3), nitrates (NO3), and nitrites (NO2) can cause hypoxia (low levels of dissolved oxygen) and can become toxic to warm-blooded animals at high concentrations under certain conditions. Nitrate levels above 10 mg/L are above drinking water guidelines. The natural level of ammonia or nitrate in surface water is typically low (less than 1 mg/L).
Sources of nitrates include wastewater treatment plants, runoff from fertilized lawns and cropland, failing on-site septic systems, runoff from animal manure storage areas, and industrial discharges that contain corrosion inhibitors.
Phosphate
Similar to nitrogen, phosphorus is an essential nutrient for the plants and animals that make up the aquatic food web. Since phosphorus is the nutrient in short supply (limiting nutrient) in most fresh waters, even a modest increase in phosphorus can, under the right conditions, set off a whole chain of undesirable events in a stream including accelerated plant growth, algae blooms, low dissolved oxygen, and the death of certain fish, invertebrates, and other aquatic animals.
Pure, "elemental" phosphorus (P) is rarely found in nature. Typically, phosphorus exists as part of a phosphate molecule (PO4). Phosphorus in aquatic systems occurs as organic phosphate and inorganic phosphate. Organic phosphate consists of a phosphate molecule associated with a carbon-based molecule, as in plant or animal tissue. Phosphate that is not associated with organic material is inorganic. Inorganic phosphorus is the form required by plants. Animals can use either organic or inorganic phosphate. Both organic and inorganic phosphorus can either be dissolved in the water or suspended (attached to particles in the water column).
There are many sources of phosphorus, both natural and human. These include soil and rocks, wastewater treatment plants, runoff from fertilized lawns and cropland, failing septic systems, runoff from animal manure storage areas, disturbed land areas, drained wetlands, water treatment, and commercial cleaning preparations.
60
4. Watershed Characteristics Assessment
Turbidity
Turbidity, a measurement of the ‘cloudiness’ of water, is caused by suspended particles, or TSS (total suspended solids). Suspended materials include soil particles (clay, silt, and sand), algae, plankton, microbes, and other substances. Higher turbidity increases water temperatures because suspended particles absorb more heat. This, in turn, reduces the concentration of dissolved oxygen (DO) because warm water holds less DO than cold. Higher turbidity also reduces the amount of light penetrating the water, which reduces photosynthesis and the production of DO. Suspended materials can clog fish gills, reducing resistance to disease in fish, lowering growth rates, and affecting egg and larval development. As the particles settle, they can blanket the stream bottom, especially in slower waters, and smother fish eggs and benthic macroinvertebrates.
Sources of turbidity include: soil erosion; waste discharge; urban runoff; eroding stream banks; large numbers of bottom feeders (such as carp), which stir up bottom sediments; and excessive algal growth. Turbidity tends to increase after rain events when runoff carries particles into the stream, when high flows erode streambanks and/or the streambed, and when the increased volume of water in the channel stirs the sediment in the bottom of the channel.
Bacteria
Additional discussion is being prepared.
Chlorides
Chloride salts are essential for aquatic health. However, when high levels of chloride contaminate fresh water streams and lakes, it becomes toxic to fish and other aquatic life forms. Chlorides may enter surface water from rocks, agricultural runoff, industrial wastewater, wastewater treatment plant effluents and, most significantly, wintertime road salts. The Illinois water quality standard for chloride is 500 mg/L.
A significant amount of water quality data has been collected in the East Branch DuPage River by numerous stakeholders including the Illinois Environmental Protection Agency (IEPA), the DuPage River Salt Creek Workgroup (DRSCW), and the Sierra Club. Locations are shown in Exhibit 15.
4.11.3.1 Data Collected by the IEPA Illinois EPA, with contractual assistance provided by the U.S. Geological Survey (USGS) and Illinois State Water Survey (ISWS), operates an Ambient Water Quality Monitoring Network (AWQMN) consisting of 146 fixed stations to support surface water chemistry data needs. Integrated water column samples are collected on a six week sampling frequency and analyzed for a minimum of 55 universal parameters including field pH, temperature, specific conductance, dissolved oxygen, suspended solids, nutrients, fecal coliform bacteria, and total and dissolved heavy metals. Additional parameters specific for the station, watershed, and/or subnetwork within the ambient network are also analyzed. Where stream flow is available from
61
4. Watershed Characteristics Assessment
the USGS water quality data are analyzed for flow-adjusted water quality trends. There is 1 AWQMN stations within the East Branch DuPage River watershed (Table 4-23)
Table 4-23 AWQMN Monitoring Stations in the East Branch DuPage River Watershed
IEPA Station USGS Station Location Code Number GBL-10 05540210 East Branch DuPage River at Illinois State Route 34 at Lisle, Illinois
In addition to the AWQMN sampling, the IEPA also conducts basin-specific surveys to characterize the chemical, physical and biological conditions of Illinois’ streams. Each year, two or three of the thirty-three major watersheds in Illinois are sampled by the IEPA. Under this cooperative agreement with Illinois Department of Natural Resources (IDNR), more than 100 stations are monitored annually for biological, chemical and physical indicators of water resource quality. This schedule allows each of the State’s major watersheds to be sampled on a five-year rotational basis. Intensive basin survey monitoring stations are routinely located at Illinois EPA Ambient Water Quality Monitoring Network stations and IDNR fish monitoring locations.
As part of the basin-specific surveys, water and sediment chemistry, physical habitat, biological (macroinvertebrate and fish) assemblages, and fish tissue samples are collected to assess stream quality. One round of biological and habitat sampling is conducted at each station, typically during summer low flow conditions. Three water samples are collected at each survey station; one prior to biological sampling, one on the day of biological sample collection and one post- biological sampling in late summer/early fall. Instream surficial sediment is also collected at each station to screen for toxic substances. Fish tissue samples are taken from fish assemblage collections (typically those stations known to support sport fishing) to screen for toxic substances. In order to minimize sample variability and enhance data comparability across time, all samples are collected within a June to mid-October time period.
The most recent basin-specific survey of the East Branch DuPage River watershed was conducted in 2013.
4.11.3.2 Water Quality Data Collected by the DRSCW The objectives of DRSCW’s monitoring in the watersheds are multi-faceted and include the following:
• Characterize water quality conditions and trends throughout the watershed; • Support the development of water quality standards and in-stream targets; • Provide technical information to help guide implementation efforts; and • Document the effectiveness of water quality management strategies.
Since 2006, the DRSCW has conducted numerous surveys in the East Branch DuPage River watershed including DO monitoring, bioassessments, and sediment oxygen demand (SOD) monitoring. Developing and implementing a monitoring program that produces credible data for decision making purposes involved various activities including establishing and 62
4. Watershed Characteristics Assessment
documenting quality assurance procedures; training or hiring certified staff; purchasing and maintaining sampling equipment; collecting and managing samples; conducting quality assurance/quality control; and managing, analyzing, and reporting data. To date the DRSCW has prepared and Illinois EPA has approved Quality Assurance Project Plans for the continuous DO monitoring program and the bioassessment sampling program. Table 4-24 details the sampling conducted by the DRSCW.
Table 4-24 Water Quality Studies Conducted by the DRSCW
Parameter(s) Dates Description Report, Analysis & Data Surveyed Collected Water 2007, Demand, nutrients, Biological and Water Quality Study of the East and West Column 2011, organics & metals Branch DuPage Rivers and Salt Creek Watersheds Chemistry * 2014* collected at (Bioassessment report) (2007, 2011, 2014*). approximately 39 http://www.drscw.org/bioassessment.html. sites. http://www.drscw.org/data.html.
Dissolved 2008 Calibrated and DO Improvement Feasibility Study. Oxygen validated QUAL 2K East Branch DuPage River. (DO) DO model QUAL 2K Model. developed for East http://www.drscw.org/dissolvedoxygen/ebdofinal.pdf. Branch DuPage River. Prioritization analysis carried out by stakeholder group.
Dissolved 2006-2014 DO, pH, Excel spreadsheet and Bioassessment reports. Oxygen (June – conductivity and (continuous) August) water temperature collected hourly. Ammonia- 2012- 2013 Sample collection Ammonia Mass Balance on the Lower East Branch DuPage Nitrogen and flow duration River curve analysis for ammonia nitrogen on St. Prentiss Creek and lower East Branch main stem
Conductivity 2008 -2015 Conductivity Conductivity and Chloride Monitoring Summary 2007/2008. (proxy for (Dec.– collected at 2 Annual updates (winter 2013/14). Chloride) March) locations.
Sediment 2007, Organics and metals Biological and Water Quality Study of the East and West Chemistry 2011, 2014 collected at Branch DuPage Rivers and Salt Creek Watersheds (2007, 2011, approximately 16 2014). sites.
Fish Survey 2007, Fish shocking survey Biological and Water Quality Study of the East and West 2011, 2014 on main stem and Branch DuPage Rivers and Salt Creek Watersheds (2007, 2011, tributaries at 2014). approximately 37 sites (2 sweeps per sample year). 63
4. Watershed Characteristics Assessment
Macro 2007, Macroinvertebrate Biological and Water Quality Study of the East and West invertebrate 2011, 2014 sampling at Branch DuPage Rivers and Salt Creek Watersheds (2007, 2011, Survey approximately 37 2014). sites. Physical 2007, Qualitative Habitat Biological and Water Quality Study of the East and West Habitat 2011, 2014 Evaluation Index Branch DuPage Rivers and Salt Creek Watersheds (2007, 2011, Evaluation (QHEI). 2014).
SOD Survey 2006 Sediment Oxygen SOD Measurement Survey East Branch DuPage River & Salt (DO Demand (SOD) Creek (2007, 2011, 2014). Feasibility measured at 8 Study) locations.
Point Source 1995-2011 Evaluation of flow Biological and Water Quality Study of the East and West Evaluation and effluent quality Branch DuPage Rivers and Salt Creek Watersheds (2007, 2011, for 7 Publicly Owned 2014). Wastewater Treatment Plants. Chlorides 2007 (Bi- Review public roads Chloride Usage Education and Reduction Program Study annual loading and source http://www.drscw.org/chlorides/ChlorideRecomendations.Fi updates) reduction measures. nal_Report.pdf. Annual questionnaire to public agencies with winter roads management responsibilities tracks progress of BMP uptake.
Aquatic Life 2012 Causal analysis of Priority rankings based on estimated restorability for stream Stressor proximate stressors segments in the DuPage River and Salt Creek Watersheds. Analysis and to aquatic life and Segment application of Prioritization prioritization algorithm to main stem and tributaries.
Canoe Survey 2006 100 geo-referenced Geo-database file. of Channel images of the East Form Branch DuPage River. Aerial Survey 2007 30 minute flyovers Geo-referenced DVD of East Branch DuPage River. of Channel USGS DVDs with geo- Form aerial referenced readout. flyover videos
* 2014 report is under development
Dissolved Oxygen Monitoring
The DRSCW launched the continuous dissolved oxygen (DO) monitoring network in 2006. Prior to that DO was monitored continuously at only one site in the Upper DuPage, at the City of 64
4. Watershed Characteristics Assessment
Wheaton under the authority of Wheaton Sanitary District and four on Salt Creek under the authority of Metropolitan Waster Water Authority of Greater Chicago (MWRDGC). To date, five DO monitoring stations have been established on East Branch DuPage River.
Each of the 5 sites are equipped with a HydroLab DS 5X and collect continuous DO and hourly data on pH, conductivity and water temperature from April through to October (the seasonal period recognized as containing the lowest annual levels of stream DO).
As the 2004 TMDL reports prepared by the IEPA for the East Branch DuPage River addressed the impact that sediment oxygen demand can have on low DO levels. The DRSCW conducted a one-time sediment oxygen demand study that involved monitoring at 8 sites throughout the watershed. The data from this monitoring project was used to develop an updated water quality model and help the DRSCW to better understand the sources affecting DO levels.
The current DO data collection, data analysis, and modeling efforts focus primarily on dry weather conditions. Given that data have also revealed DO concerns in wet weather conditions, the DRSCW is considering initiating work focused on the impacts of wet weather events on DO levels in the watersheds.
Bioassessment Program
In 2006 the Workgroup also initiated an extensive bioassessment program within the watershed. This component of the monitoring work will provide expanded information about water quality conditions across the watersheds from a spatial perspective. Through bioassessment sampling, the DRSCW established baseline information on fish, macroinvertebrates, and habitat, as well as water and sediment chemistry. To track trends, subsequent sampling will be conducted every three years. The 43 sites in the East Branch DuPage River watershed was sampled in 2006, 2011, and 2014.
Chlorides
Discussion is currently being prepared.
4.11.3.3 Water Quality Data Collected by the Sierra Club DuPage County’s local Sierra Club group, the River Prairie Group, conducts water tests on rivers throughout the county. Their River Monitoring Project, launched in January 2000, performs quarterly and monthly testing on a number of sites in the East Branch of the DuPage River watershed (Table 4-25). Most aspects of the tests are performed by local Sierra Club volunteer and collected river samples are routinely tested for four chemicals (phosphate, nitrate, ammonia, chloride), temperature, pH, and in some areas, dissolved oxygen, and mercury. The group summarizes the test results on their website (http://illinois.sierraclub.org/rpg/watermonitorproj.htm), to educate DuPage residents about the waterways in their backyards. Their test data is also valuable to researchers, educators, and policymakers, and have ongoing value, providing a baseline against which the rivers’ water quality can be analyzed in the future.
65
4. Watershed Characteristics Assessment
Table 4-25 Sierra Club Sampling Sites in the East Branch DuPage River watershed
Site Site Name Site Location Identification Number EB1 East Branch DuPage River - Churchill Woods Forest Preserve in Glen Ellyn. Sampling site Churchill Woods Forest Preserve was previously the shore of the river's south channel; in April 2006, it was moved to the bridge on the north channel EB2 East Branch Dupage River - Pedestrian bridge on north shoulder of Butterfield Road Butterfield Rd. approximately ¼ mile east of Route 53, in Downers Grove EB3 East Branch DuPage River - Sampling site was previously the shore near Ogden Avenue Burlington Ave. and Route 53; in April 2000, it was moved to the shore approximately fifty yards south of the BNSF bridge (intersection of Dumoulin and Burlington avenues). EB4 East Branch DuPage River - St. Shore of St. Joseph's Creek, approximately fifty yards south of Joseph's Creek Ogden Avenue in Lisle Source: http://illinois.sierraclub.org/rpg/watermonitorproj.htm
4.11.4. Nonpoint Pollution Sources & Load Analysis When rain flows across the landscape, pollutants such as oil and grease, road salt, eroding soil and sediment, metals, bacteria from pet wastes, and excess nutrients (nitrogen and phosphorus) from fertilizers are washed from streets, buildings, parking lots, construction sites, lawns and golf courses into the streams. This kind of pollution is called nonpoint source pollution, because it comes from the entire watershed rather than a single point, plant, or facility. These pollutants accumulate as the water flows downstream and eventually begin to degrade the quality of East Branch waters for aquatic life, as well as, for human uses such as fishing, wading, and bird watching. In this way, every small bit of pollution adds up to a very large problem.
In addition to chemicals and other substances picked up from the landscape, nonpoint source pollution includes other measures such as temperature, acidity, and the amount of oxygen in the water. Aquatic organisms including fish and benthic macroinvertebrates that are critical links in the food chain, need oxygen that is dissolved in the water to breathe. Low flows and nonpoint source pollution can cause the dissolved oxygen levels in the water to fall below healthy levels. When this happens, some plants and animals will die, including fish kills, Other animals will leave that location to try to find cleaner water.
Elevated water temperature from stormwater crossing heated surfaces also causes problems. Many fish and other aquatic animals require cool or cold flowing water to survive. As rainwater flows across urban surfaces and through the sewer system, these surfaces warm the water causing the overall temperature of the receiving stream to be too warm for many aquatic plants and animals. This water can also be either more acidic (low pH) or more alkaline (high pH) than is healthy for these organisms to survive.
4.11.4.1 Nonpoint Source Pollutant Load Analysis Pollutant load modeling for the East Branch DuPage River watershed is ongoing. A discussion on current water quality standards will be included in this section.
66
4. Watershed Characteristics Assessment
4.12. Critical Areas for Watershed Improvement The intent of identifying Critical Areas is to focus watershed improvement efforts on areas where impairments are concentrated or relatively worse than in other areas of the watershed. Restoration, prevention, and remediation efforts in these Critical Areas are expected to achieve a greater impact than in less critical parts of the watersheds. These results and recommendations for watershed improvement will be incorporated into the Watershed Plan.
4.12.1. Critical Subbasins Identification of critical subbasins is pending.
4.12.2. Critical Stream Reaches Identification of critical stream reaches is pending.
4.12.3. Summary and Conclusions This section will reflect the results of the nonpoint source pollutant load analysis and critical identification area analysis. As such, this section is pending.
67
5. Land Use, Demographics and Transportation This section concerns the human settlements and systems within the East Branch watershed – both how these systems affect conditions within the stream, and how human systems are affected by natural watershed processes. 5.1. Watershed Land Use and Land Cover Evaluating the land uses of a watershed is essential to understanding the hydrologic conditions, pollutant sources and loading, and dynamics. Land use and land cover types, together with other physical features such as soils and topography, influence the hydrologic and physical nature of the watershed. The volume of stormwater runoff, and the amount and type of non- point source pollution in stormwater runoff, is to a very large extent a function of land use and land cover type, making this perhaps the most important parameter to understand in determining the sources and loading of various pollutants and possible reduction strategies.
5.1.1. Historical Land Use Understanding when and how a watershed developed is essential to understanding its function, stressors, and in many cases, its flooding patterns. The East Branch watershed has undergone a transition from native prairie and forest ecosystems to agriculture, and subsequently to suburban and urban land uses, that resulted in modifications to the River’s tributaries, its main channel, its hydrology, and the types and sources of pollutants reaching the River.
1972 Land Use data for the East Branch DuPage River watershed was obtained from the United States Geological Survey (USGS) GIRAS Land Use and Land Cover database. USGS GIRAS Land Use and Land Cover for the East Branch DuPage River watershed is summarized in Table 5-1 and depicted in Exhibit 16.
Table 5-1 United States Geological Survey (USGS) GIRAS Land Use and Land Cover for the East Branch Watershed (DuPage County Portion)
USGS GIRAS Land Use and Description Acres Percent of Land Cover Type Watershed Commercial and Services: Contains commercial areas used predominately for sale of products and services; urban business districts, shopping centers, commercial strip developments, junkyards, resorts, etc. Institutional land uses such as educational, religious, health, correctional and military facilities are also included in this land use. Combined Animal Feeding Operations: Land cover than contains areas used predominately for specialized livestock production including beef cattle feedlots, dairy operations with confined feeding, large poultry farms, and hog feedlots. Cropland and Pasture: agricultural land used for harvest and pasture. Deciduous Forest Lands: all forested areas having a predominance of trees that lose their leaves at the beginning of the forest system or at the beginning of a dry season. Evergreen Forest Land: all forested areas dominated by trees where 75 percent or more of the tree species `maintain their leaves all year. Canopy is never without green foliage. Industrial: commercial areas used predominately for the manufacturing, production, and warehousing of goods. Mixed Urban or Built-Up Land: commercial areas where one third of the land area is comprised of a non-commercial use such as residential or institutional; typically downtown business districts. 68
5. Land Use, Demographics and Transportation
Orchards, Groves, Vineyards, Nurseries, and Ornamental Horticulture: areas utilized as orchards and groves that produce fruit and nut crops and nurseries and horticulture areas such as seed-and-sod areas, greenhouses, and floriculture Other Agricultural Lands: other agricultural land uses not included in confined feeding operations, crop and pasture lands, and orchards, vineyards, nurseries, & horticulture; typically include farmsteads, holding areas for livestock, breeding & training facilities on horse farms, similar uses. Other Urban or Built-Up Land: golf driving ranges, zoos, urban parks, cemeteries, waste sumps, water-control structures and spillways, golf courses, and ski areas Reservoirs: artificial impoundments of water used for irrigation, flood control, municipal water supplies, hydroelectricity, recreation, and similar uses. Residential: residential areas ranging from high density to low density. Strip Mines: extractive mining activities with a significant surface expression Transportation, Communication and Utilities: roads, railways, airports, seaports, and major lake ports Transitional Areas: Areas in transition from one land use activity to another
5.1.2. Current Land Use and Land Cover To assess change in land use and current land use, 2010 land use data for DuPage County was obtained from the Chicago Metropolitan Agency for Planning (CMAP) and summarized in Table 5-2 below. The definitions vary slightly from the 1972 USGS data above
Table 5-2 CMAP Existing Land Use for the East Branch Watershed
Land Use Description Acres Percent of Watershed Agriculture agricultural land used for harvest and 212 0.44% pasture Conservation/ Open parks, golf courses, nature preserves, 10,410 21.6% Space playgrounds and athletic fields when associated with another open space activity; wetlands, open water and riparian corridors; parks and open areas located in residential, commercial, and industrial areas Industrial manufacturing and processing, 1,255 2.6% warehousing and distribution centers, wholesale facilities, and industrial parks Infrastructure roads, railways, airports, seaports, and 9,926 20.6% major lake ports; also includes non- parcel data Institutional large institutional structures such as 2,236 4.7% schools and governmental administration buildings Mixed Use various types of residential and 711 1.9% commercial land uses are grouped or clustered together as a planned development Multi-Family multi-family and duplex residential 1,757 3.7% Residential properties of varying density Office primary usage of structures is for office 1,171 2.4% 69
5. Land Use, Demographics and Transportation
space and/or business park and limited or no retail sales occur Retail/Commercial commercial areas used predominately for 2,332 4.8% sale of products and services (includes urban business districts, shopping centers, commercial strip developments, etc.) Single Family single family residential properties of 18,121 37.7% Residential varying densities
5.1.3. Future Land Use / Land Cover Projections Information on future built out lands for the DuPage County portion of the watershed was obtained from the DuPage County Zoning Map.
It is often useful to compare existing land use data to future land use data to identify anticipated changes within the watershed. Due to difference in the way the values of the two data sets were calculated, a direct comparison of the two data sets is not practical. For example the 2010 CMAP Land Use data includes park and open space areas located within residential areas in the Conservation/Open Space data set while the DuPage County Zoning data includes these areas in the Multi-Family Residential and Single Family Residential data. However, the data is still useful in predicting general trends. The available data indicated that single family residential, office and mixed use areas are likely to increase as a share of land use in the watershed as shown in Table 5-3. Future land use is shown in Exhibit 17.
Table 5-3 Projected Land Use for the East Branch Watershed
20XX Land Use Estimated Percent of 2010 Trend as % of watershed area Acres Watershed Estimate (positive, neutral, negative) (Acres) Agriculture 0 0% 212 = Conservation/ Open 8,031 20.1% 10,410 Space Industrial 1,802 4.5% 1,255 - Infrastructure 434 1.2% 9,926 Institutional 115 0.3% 2,236 Mixed Use 76 0.2% 711 + Multi-Family 1,951 4.9% 1,757 = Residential Office 3,298 8.3% 1,171 + Retail/Commercial 1,032 2.6% 2,332 Single Family 23,159 58.1% 18,121 + Residential
70
5. Land Use, Demographics and Transportation
5.1.4. Land Use Impacts on the East Branch Watershed The conversion of agricultural lands to residential and retail/commercial land uses increases the amount of impervious cover for a given area and reduces the amount of open space available for infiltration and storing storm water runoff. Imperviousness is generally defined as the sum of roads, parking lots, sidewalks, rooftops, and other surfaces within an urban landscape that prevent infiltration of storm water runoff. Imperviousness can be used to measure the impacts of urban land uses on aquatic systems. For example, an increase in imperviousness has negative implications on the natural functions of streams including water quality; hydrology and flows; flooding and depressional storage; and instream and riparian habitat.
Water Quality
Increases in impervious area negatively affect water quality in streams and lakes by increasing both pollutant loads from over-land transport of storm waters into surface waters or storm drains, and from increases in water temperature (known as thermal pollution). During dry conditions, land surfaces accumulate pollutants including nutrients, sediment, oils, bacteria, and metals from the atmosphere, vehicles, roof surfaces, lawns, and other sources. During storm events, these pollutants are washed from the impervious surface and delivered to streams and lakes. Additionally, runoff from impervious surfaces is typically 12 degrees (Fahrenheit) higher in temperature than runoff from vegetated areas. As these warmer flows enter streams, habitat and ability to sustain aquatic life can be impaired; water temperatures over 68°F may preclude most fish from using the streams for habitat.
Hydrology and Flows
Hydromodification is a term that is used to describe human activities that change the dynamics of surface or subsurface flow. The process of urbanization affects streams by altering watershed hydrology and sediment-transport patterns. Development increases the amount of impervious surfaces (parking lots, rooftops, highly compacted ground, etc.) on formerly undeveloped landscapes. This reduces the amount of remaining pervious surfaces available to capture and filter rainfall, and allow the rainfall to infiltrate into the ground. As a result, a larger percentage of rainfall becomes runoff during any given storm. Subsequently, runoff reaches stream channels much more quickly, and peak discharge rates and volumes are higher than before development for the same size rainfall event.
Habitat
Increased impervious cover negatively affects stream habitat and its associated biological communities (fish, macroinvertebrates, amphibians, etc.). As discussed above, hydromodification and the process of stream bank erosion and channel incision causes a significant amount of sediment to be generated within the stream and carried through the watershed. The sediment suspended in the water causes turbid conditions that can be detrimental to aquatic organisms; once it falls out of the water column, the deposited sediment negatively affects aquatic organisms by filling interstitial spaces in substrates that are necessary
71
5. Land Use, Demographics and Transportation for macroinvertebrate and fish propagation . Physical habitat degradation can also occur when hydromodification causes loss of riffle-pool structures and loss of riparian cover.
5.1.5. Impervious Area Analysis As discussed above in Section 5.1.4, impervious area can be used to qualitatively and to some extent quantitatively measure the impacts of urban land uses on aquatic systems. Studies on impervious areas have indicated that stream health begins to degrade when the watershed reaches approximately 10% impervious cover, due to changes in vegetative cover and function, hydrologic modification during storms, and reductions in stream base flows as more stormwater flows over land and less infiltrates into the ground, ultimately recharging a stream or river.
The Impervious Area Analysis for the East Branch was used to help understand how stream quality relates to the subwatershed areas that drains to a particular stream reach. This analysis uses the subbasins described in Section 4.11.4 and illustrated in Exhibit 2. GIS was used to estimate the area of existing and projected land use/land cover by subbasin. Impervious cover was then calculated by assigning an impervious cover percentage attributable to each land use/land cover type in Table 5-4 above and projecting this across each subwatershed. The impervious cover percentages, listed in Table 5-4 below, are based upon data collected for the Metropolitan Water Reclamation District of Greater Chicago (MWRD) in Northeastern Illinois.
Table 5-4 Total Impervious Cover by Land Use/Land Cover Type (2010)
Land Use Percent Impervious Total Associated (MWRD Analysis) Impervious Cover – East Branch Watershed Agricultural 5% Conservation Neighborhood 15% Forest and Grassland 5% Government, Civic and Institutional 72% Industrial 72% Mixed Residential 65% Mixed Use 85% Multifamily Residential 65% Office Space 85% Open Space/Conservation/Parks 5% Retail/Commercial 85% Single-family Residential 30% Transportation 95% Utility/Waste Facility 5%
Data Analysis is ongoing. 5.2. Watershed Socioeconomic and Demographic Conditions DuPage County occupies a prominent place within the greater Chicago region’s economy. The transportation networks, residential areas and commercial corridors in the East Branch watershed are integral to the economy and social character of the County. For watershed 72
5. Land Use, Demographics and Transportation planning, the demographic and socioeconomic analysis is important for several purposes. Understanding the basic population density and trends in a watershed informs planning for future development as well as retrofits in existing areas. In addition, specific data analysis informs three other components of watershed management and resilience:
1. Improving education, outreach and engagement: Understanding watershed demographics allows the County and other stakeholders to design more effective education and outreach for local neighborhoods and groups. 2. Identifying vulnerable populations: Areas with concentrations of children or elderly residents, below-average incomes or home values, or aging housing stock may also be vulnerable to impacts from flooding and severe storms. Households where English is not a first language, or where residents are transit dependent, also warrant identification and special planning for flood or weather events. While DuPage County is, on the whole, wealthier in terms of household and per capita income than the Chicago region as a whole, there are pockets within the East Branch watershed where low- to moderate-income households (as defined by the U.S. Department of Housing and Urban Development) predominate and transit is lacking, as well as areas with concentrations of elderly residents and neighborhoods where English is not the first language. 3. Planning for flood damage resilience: In areas where there has been repeated flood damage to homes and buildings, the profile of housing tenure (ownership versus renting), home and business values, and structure age is especially important. Planning for flood-prone areas must take into account the potential loss of value from flood damage, the potential cost of repairs, and the likely cost of buyouts where acquisition is pursued. All of these decisions should be informed by demographic and economic analysis.
This Section describes the population and housing characteristics of the County, East Branch watershed, and for certain data, the U.S. Census tracts in three chronically flood-prone areas of the East Branch watershed: The Valley View area along Route 53 south of Glen Ellyn and North of Lisle; downtown Downers Grove; and the River-Dumoulin area in Lisle at the confluence of St. Joseph’s Creek and the East Branch, where flooding was particularly acute in the April 2013 flood event.
5.2.1. Population Table 5-5 below provides key population and household information for the County, Watershed, and three flood-prone areas1. Roughly one-quarter of the population of DuPage County lives within the boundaries of the East Branch watershed. While the populations in the three flood- affected areas represent a very small share of the County and watershed totals, these areas represent a substantial share of the County-wide damage from the April 2013 flood event, and a significant amount of the remaining unmet need for repairs, buyouts, and flood-related improvements.
1 For purposes of this analysis, the three flood prone areas were defined by selecting the 2010 US Census tract or tracts whose boundaries most closely aligned with County mapping of chronic flooding areas. 73
5. Land Use, Demographics and Transportation
Table 5-5 2013 Population and Household Structure
DUPAGE EAST VALLEY RIVER- DOWNTOWN COUNTY BRANCH VIEW DUMOULIN DOWNERS WATERSHED (UNINCORP. LISLE GROVE COUNTY) POPULATION Total Population 916,924 254,994 4,561 7,695 12,240 % of County 100% 27.8% 0.5% 0.84% 1.33% White Only 714,140 199,596 4,106 6,557 10,968 Percent 77.9% 78.3% 90.0% 85.2% 89.6% HOUSEHOLDS Total Households 337,132 98,831 1,715 3,369 4,948 Average Household 2.73 2.61 2.66 2.23 2.47 Size Single Householder, 21,811 6,413 89 166 269 children present Percent 6.5% 6.5% 5.2% 4.9% 5.4% All households, 119,774 32,402 599 828 1,549 children present Percent 35.5% 32.8% 34.9% 24.6% 31.3% Householder 85+ years 10,156 3,246 40 355 168 Percent 3.0% 3.3% 2.3% 10.5% 3.4% Source: 2013 American Community Survey; Hey & Associates/Birchline Planning LLC
The size and composition of households is important information for flood resilience planning. Households in two of the East Branch’s flood-affected areas (Downers Grove and particularly River-Dumoulin) are notably smaller than the County- and watershed-wide averages. Even more important, 10.5% percent of households in the River-Dumoulin area are single individuals ages 85 years and over, compared with only 3% of households in the County and only 2.3% in the Valley View area. This area also has a smaller average household size and a lower proportion of households with children present – 24.6% compared to roughly 33% on average elsewhere in the watershed and County. During flood events older people living alone are particularly vulnerable to both primary (structure flooding) impacts and secondary impacts, such as a lack of access to health care due to flooded roads and reduced options for temporary relocation. Taken together, this presents a profile of an aging neighborhood with fewer younger households, an important consideration for outreach, education and potentially buyouts.
Like DuPage County as a whole, the East Branch watershed and the flood-prone areas studied show very high educational attainment relative to the Chicago region and the US as a whole. The percent of households where English is limited is lower in the East Branch watershed and each of the flood-prone areas than in the County as a whole; nonetheless, the County and municipalities may need to identify second-language needs for emergency communications and post-flood recovery work.
74
5. Land Use, Demographics and Transportation
Table 5-6 Educational Attainment and Language
DUPAGE EAST VALLEY RIVER- DOWNTOWN COUNTY BRANCH VIEW DUMOULIN DOWNERS WATERSHED (UNINC. (LISLE) GROVE COUNTY) High School graduate 92.6% 94.6% 99.0% 94.9% 94.0% Bachelor’s degree or 46.6% 48.3% 61.6% 41.9% 48.4% higher Population 5 yrs and older 73.7% 77.1% 80.2% 84.3% 84.4% - Speak only English at home Household, Primary 8.1% 7.5% 8.6% 6.0% 5.4% Language is not English, but Not Limited Speaking English Household, Limited 16,421 4,342 65 70 193 English Percent 1.8% 1.7% 1.4% 0.9% 1.6% Source: 2013 American Community Survey
5.2.2. Income Profile & Low-Moderate Income Areas A review of household income and Census tracts with substantial shares of low and moderate income households helps identify other areas with potential vulnerabilities during flood or other emergency events in the watershed. These households also have greater potential for economic disruption if homes are damaged or become uninhabitable from flooding, or if floods or severe storms disrupt transportation systems.
Within the East Branch watershed, the distribution of household incomes is very similar to the County-wide profile, with the exception of the higher share of households with less than $25,000 in annual income in downtown Downers Grove (17.5% of households versus 9.2% County-wide, and 9.5% in the East Branch watershed). Also notable is the disparity between family income and household income in the River-Dumoulin area. The Census defines a “family” as a married/civil union couple with or without children; the term “household”, by contrast, encompasses all types of household structures including individuals living alone, single-parent households, or unmarried couples. Families tend on the whole to have higher household incomes; as such, a gap between median household income and median family income often indicates that a larger share of non-family households such as elderly persons living alone or single-parent families have substantially less annual income than family households in a given area. This appears to be the case in the River-Dumoulin area, which has a high percentage of householders age 85 and older. Median household income in the River- Dumoulin area is markedly lower than for the watershed as a whole or the County, and for median family income within the same Census tract area, indicating that the many households comprised of one elderly person noted in Section 5.2.1 above also may have lower incomes than are typical in the area as a whole.
Table 5-7 Household Income Distribution (Household Income in the past 12 Months in Current 2013 Dollars) 75
5. Land Use, Demographics and Transportation
DUPAGE EAST VALLEY RIVER- DOWNTOWN COUNTY BRANCH VIEW DUMOULIN DOWNERS WATERSHED (UNINC. (LISLE) GROVE COUNTY) Under $24,999 9.2% 9.5% 5.1% 10.7% 17.5% $25,000 to $74,999 24.3% 26.4% 20.5% 26.4% 21.6% $75,000 to $124,999 36.1% 35.1% 36.3% 29.8% 30.3% $125,000 or more 30.5% 29.0% 38.2% 33.1% 30.6% Per Capita Income $38,896 $38,919 $41,430 $41,370 $36,736 Percent of County 100.0% 100.1% 106.5% 106.4% 94.4% Median household income $79,383 $71,575 $91,136 $64,737 $76,375 Percent of County median 100.0% 90.2% 114.8% 81.6% 96.2% Median family income $95,436 $92,177 $108,536 $101,444 $104,238 Percent of County median 100.0% 96.6% 113.7% 106.3% 109.2% Source: 2013 American Community Survey
Unemployment and disability status reflect workforce engagement and, for many purposes, economic robustness in an area. Rates of unemployment are comparable in the East Branch watershed and slightly lower in the focus areas; the notably lower rate in the River-Dumoulin area may be a result of the higher proportion of households headed by elderly persons, who are less likely to be part of the labor force and thus would not be employed. The proportion of persons between 18 and 64 with a disability status is slightly elevated in the River-Dumoulin area, but in general rates within the watershed are very close to those for the County as a whole.
Table 5-8 Employment and Disability Status
DUPAGE EAST VALLEY RIVER- DOWNTOWN COUNTY BRANCH VIEW DUMOULIN DOWNERS WATERSHE (UNINC. (LISLE) GROVE D COUNTY) Unemployment Rate, 8.5% 8.8% 7.4% 5.0% 7.0% population 16 yrs and older Disability Status, with any 3.5% 3.8% 2.9% 4.1% 3.8% disability (18 to 64 yrs) Source: 2013 American Community Survey
Census tracts with low- and moderate-income households also are important to identify, both in terms of potential economic vulnerability if flooding occurs and homes are damaged, and in terms of identifying eligibility for different types of grants and programs targeted towards these areas. Table 5-9 below shows the income limits considered “Low,” “Very Low” and “Extremely Low” for DuPage County for Fiscal Year 2014. Exhibit 18 shows the census tracts throughout the watershed that have a substantial percentage of low or moderate income households. Notably, few of these defined low-moderate income geographies line up precisely with areas of recurrent flooding in the watershed. However, the impact of watershed conditions on low- and moderate-income areas remains important to watershed planning. The environmental 76
5. Land Use, Demographics and Transportation condition of the East Branch affects recreational use of the River in public parks and recreation areas, several of which (such as the Churchill Woods natural area in Glen Ellyn) are adjacent to the low-moderate income areas identified on the map. Transportation system disruptions during storms and floods, as noted above, also can have a disproportionate impact on low- and moderate-income households, particularly when the ability to travel to work is affected or businesses must temporarily close.
Table 5-9 FY2014 Income Limits for Low, Very Low & Extremely Low Income Households
DuPage County, IL Persons in Family: 1 2 3 4 5 Low (80% of County) $40,500 $46,350 $52,150 $57,900 $62,550 Very Low (50% of $25,350 $29,000 $32,600 $36,200 $39,100 County) Extremely Low (30% of $15,200 $17,400 $19,790 $23,850 $27,910 County) Source: US Department of Housing & Urban Development
5.2.3. Economic Activity & Industry Profile Economic activity in the East Branch watershed affects water quality, flooding and environmental quality in several ways. From a positive standpoint, a robust local economy provides taxes, private investment, cooperative partnerships and matching funds that are essential to completing watershed protection projects such as land conservation, stream restoration, flood risk reduction, and where necessary, property buyouts. Conversely, land development and transportation systems that support the County’s economy have led to loss of wetlands and storage capacity for rainfall, increased stormwater runoff, and greater pollutant loads in the East Branch, particularly before contemporary regulations and the DCSSFPO were put in place.
From the standpoint of flood resilience, it is important to identify where and how industry and the economy in the watershed are affected by flood events and where strategic actions, whether structural or operational, can reduce the potential for disruption and economic loss in the County. During this watershed planning process, manufacturing (which still represents one job in ten in DuPage County) was identified as an industry that could potentially be adversely affected by over-bank flooding damaging structures, power disruptions from flooding or heat waves, or by flood- or power-related disruptions to the transportation system – particularly Route 53.
Choose DuPage has prepared periodic Cluster Studies, the most recent in 2013, to provide a detailed analysis of each cluster, identifying industries within a particular cluster as leading, emerging, or mature based off of three benchmarks (employment growth, concentration, and wage). Since clusters are linked through the buyer-supplier relationship, they share common resources, depends on similar labor pools and institutions and on special infrastructure. Table 5-10 below shows the economic sectors in the County and their anticipated growth through 2016. 77
5. Land Use, Demographics and Transportation
Table 5-10 2013 and Projected 2016 Jobs by Industry, DuPage County
Industry 2013 Jobs Projected Average 2016 Jobs Employment Growth Management 26,065 28,481 9.3% Wholesale Trade 48,992 48,325 -1.4% Professional Services 52,991 57,634 8.8% Administrative Services 51,696 53,992 4.4% Education 15,565 17,648 13.4% Transportation and Warehousing 23,626 24,534 3.8% Finance and Insurance 31,891 31,898 0.0% Real Estate 8,751 8,794 0.5% Manufacturing 51,865 47,999 -7.5% Utilities 2,480 2,291 -7.6% Retail Trade 62,312 62,058 -0.4% Health Care 58,810 64,417 9.5% Hotel and Food Services 41,111 42,950 4.5% Information Technology 9,915 8,862 -10.6% construction 21,110 19,710 -6.6% Arts and Entertainment 5,651 5,830 3.2% Government 52,246 52,859 1.2% Agriculture 415 372 -10.4% Mining 139 134 -3.6% Source: Choose DuPage Industry Cluster Study Report 2014
5.2.4. Housing & Home Ownership The housing and home ownership characteristics of the East Branch watershed are very comparable to those of Du Page County as a whole, as shown in Table 5-11. Housing characteristics of the watershed closely resemble those of Du Page County as a whole in terms of vacancy rate, proportion of single family and multi-family units, owner occupied versus renter occupied units, household size and reported home value.
With respect to home ownership, the East Branch watershed has a slightly higher proportion of owner-occupied homes than the County as a whole. Conditions within specific focus areas, however, differ from the County and watershed profile. The Valley View area has a higher proportion of home owners than the County as a whole, and the River-Dumoulin area a substantially lower proportion with more units occupied by renters.
Table 5-11 Housing Tenure, Values and Characteristics
DUPAGE EAST VALLEY RIVER- DOWNTOWN COUNTY BRANCH VIEW DUMOULIN DOWNERS WATERSHED GROVE Total Number of 336,028 99,022 1,702 3,379 4,787 Occupied Housing Units 78
5. Land Use, Demographics and Transportation
Owner-Occupied 250,115 71,000 1,453 2,221 3,313 Housing Units Percent 74.4% 71.7% 85.4% 65.7% 69.2% Renter-Occupied 85,913 28,022 249 1,158 1,474 Housing Units Percent 25.6% 28.3% 14.6% 34.3% 30.8% Source: 2013 American Community Survey
Understanding the age of housing structures in a watershed or area, and the periods when construction took place, provides helpful information for stormwater watershed management. Because engineering and floodproofing practices change over time, knowing how many structures in a particular area were constructed at various times can provide insights on where, as an example, having roof downspouts connected to sanitary sewers may be more common, or where street drainage consists of vegetated swales rather than curbs and drains. As illustrated in the Table and Figure below, the timing of housing development in the East Branch watershed closely mirrored development in the County. Downers Grove, which is an historic downtown, has both the largest percentage of structures built before 1939 and the largest percentage built after 2000 of any of the areas evaluated. The River-Dumoulin area had the steadiest pace of development, with 326 units constructed in 1939 or earlier, at least 150 or more units added in every decade since. Valley View, by contrast, was completely principally between 1950 and 1979. Notably for the watershed as a whole, housing construction tapered off significantly after 2010.
Table 5-12 Age of Housing Structures
STRUCTURE AGE DUPAGE EAST VALLEY RIVER- DOWNTOWN COUNTY BRANCH VIEW DUMOULIN DOWNERS WATERSHED GROVE Built 1939 or earlier 20,561 6,555 10 326 867 Built 1940 to 1949 10,620 3,018 20 157 229 Built 1950 to 1959 39,438 11,973 262 585 953 Built 1960 to 1969 47,406 17,830 629 380 916 Built 1970 to 1979 85,544 29,929 406 796 1,132 Built 1980 to 1989 65,296 17,927 167 510 379 Built 1990 to 1999 54,452 9,604 146 512 230 Built 2000 to 2009 32,068 7,879 158 322 514 Built 2010 or later 832 262 0 5 19
79
5. Land Use, Demographics and Transportation
Figure 5.1 Percent of Housing Units Constructed by Decade
40%
35%
30% DUPAGE COUNTY 25% EAST BRANCH WATERSHED 20%
VALLEY VIEW 15%
RIVER-DUMOULIN 10%
DOWNTOWN DOWNERS 5% GROVE
0%
Source: American Community Survey 2013; Birchline Planning LLC
In addition to the age of housing structure, the value of housing also informs planning for flood- prone areas. Table 5-13 and Figure 5-2 below show the 2013 value of owner-occoupied housing units in the County, watershed and focus areas. Valley View generally has a higher proportion of high-value structures than the County, watershed or other focus areas; The River-DuMoulin area has a lower median value and a smaller percentage of structures valued at $500,000 or more (and none valued at $1,000,000 or more) than the County, watershed or other focus areas. This becomes important for communities in understanding the potential cost and property tax implications of buyout programs.
Table 5-13 Value of Owner-Occupied Housing Units, Median Value, Median Rent & Substandard Status
DUPAGE EAST BRANCH VALLEY RIVER- DOWNTOWN COUNTY WATERSHED VIEW DUMOULIN DOWNERS GROVE Less than $50,000 4,359 1,110 28 25 43 $50,000 to $99,999 8,166 3,144 17 88 59 $100,000 to $149,999 17,928 5,303 8 115 142 $150,000 to $199,999 31,188 8,317 28 307 252 $200,000 to $299,999 73,084 21,295 528 806 1,093
80
5. Land Use, Demographics and Transportation
DUPAGE EAST BRANCH VALLEY RIVER- DOWNTOWN COUNTY WATERSHED VIEW DUMOULIN DOWNERS GROVE $300,000 to $499,999 79,080 22,148 553 737 1,236 $500,000 to $999,999 29,840 8,577 231 143 433 $1,000,000 or more 6,470 1,106 60 0 55 Median Value $281,150 $272,250 $332,100 $264,700 $317,600 Median Monthly Rent $1,152 $1,077 $923 $979 $999 Substandard (Lacking 621 172 0 0 0 complete plumbing) Source: 2013 American Community Survey
Figure 5.2 Distribution of Value of Owner-Occupied Housing Units
40%
35%
30%
25% DUPAGE COUNTY
20% EAST BRANCH WATERSHED 15% VALLEY VIEW 10% RIVER-DUMOULIN 5%
0% DOWNTOWN DOWNERS GROVE
Source: American Community Survey 2013; Birchline Planning LLC
5.2.5. Community Facilities Community facilities that provide essential services and disaster or crisis-time services are an important part of the watershed’s social infrastructure and resilience. Exhibit 19 shows the relative location of 52 health/safety facilities and 62 government service facilities that were located within the areas most affected by the April 2013 flood event, as shown on the “Heat Map” (Exhibit 20) and this figure. Much of the impact came from the five major road closures that occurred, which are depicted on Figure 5-3. Generally, access to any facilities located within one mile of any road closure is likely to be constrained; 44 health/safety facilities and
81
5. Land Use, Demographics and Transportation
thirty government service facilities are located within one mile of a road that was closed during the April 2013 flood event.
5.2.6. Community & Organizational Resources Community and Organizational Resources within the East Branch watershed provide links for food, clothing and shelter during the immediate occurrence and aftermath of flood events, and also provide ongoing services to people and households who are displaced, who lose wages and salaries due to work interruptions, who are affected by mold, and who participate in buyout programs. Table 5-14 below describes the major community organizations and resources that provided some support during the April 2013 flood event, and their potential future roles in resilience support.
Table 5-14 Community Organizations and Resources
Physical Response Participation in Potential Planning/ Location(s) Capabilities 2013 Flood Relief Resilience Support American Red Cross of Greater Chicago Catholic Charities DuPage County Office of Homeland Security & Emergency Management (OEM) The Salvation Army Benedictine Emergency shelter University Operation Helping Hand Food Pantries (Lisle Township, REACH, Glen Ellyn, FISH Downers Grove, St Vincent DePaul Downers Grove & Lombard, St Matthew Glendale Hts, Lombard Villa Park)
5.3. Transportation The transportation system is essential infrastructure, underpinning the economy and land use in any settled area. The function of the transportation system and its continued use during floods is important to community resilience, public services and the economy. In addition to overbank flooding leading to road closures, the transportation system has impacts on pollutant loading and river function. Runoff from road surfaces and particularly deicing activities contributes substantially to non-point source pollutant loads, and improperly or under-sized in-stream 82
5. Land Use, Demographics and Transportation
bridge and culvert structures aggravate channel instability, habitat loss and flooding. Therefore in a watershed plan, the transportation system must be evaluated both from risk standpoint, and from how practices and projects can make the transportation system more watershed-friendly.
The impact of streets and highways on the watershed, particularly water quality, is significant. Table 5-15 lists a number of water quality pollutants and their sources, all of which are associated with the transportation system. Rain water flowing over roadway surfaces can carry these pollutants into our wetlands and streams, where pollutants can accumulate and impair the ability of these resources to support aquatic life.
Table 5-15 Transportation Related Pollutants
Pollutant Primary Sources Particulates Pavement wear, atmosphere, vehicles Nutrients including nitrogen and Atmosphere, fertilizer application phosphorus Lead Tire wear, exhaust Zinc Tire wear, motor oil and grease Iron Rust, steel highway structures, engine parts Copper Metal plating, break lining wear, engine parts, bearing and bushing wear, fungicides and pesticides Cadmium Tire wear, insecticides Chromium Metal plating, engine parts, break lining wear Nickel Diesel fuel, gasoline, oils, metal plating, break lining wear, asphalt paving Manganese Engine parts Cyanide Anticake compound used in deicing salts Sodium, Calcium, Chloride Deicing salts Sulfate Fuel, deicing salts Petroleum Spills and leaks of motor oils, antifreeze and hydraulic fluids, asphalt surface leachate
5.3.1. Existing Transportation Network & Issues Transportation issues take the form of water inundation that results in reduced accessibility within portions of the watershed and increased travel times due to road/lane closures. Figure 5- 3 shows the impacts to the local road network during the 2013 flood. The most significant impacts were in the form of major road closures, most notably Route 53, as outlined below.
Major Road Closures Resulting from the April 2013 Flood
• IL 53 (IDOT) south of IL 56 Butterfield Road • IL 53 (Warrenville Road to Maple Avenue) • Maple Avenue (DuPage DOT) west of IL 53 • Highland Avenue (DuPage DOT) between 31st Street and 39th Street • 55th Street (DuPage DOT) between Main Street and Fairview Avenue
83
5. Land Use, Demographics and Transportation
Figure 5-3 illustrates the impacts of the 2013 on the surface transportation system major roads. In addition to impacts on major roads, there were numerous cases of local roads being inundated with flood water, making access to individual homes difficult or impossible. The effect of impacts on the roadway system included: a) delayed response time in providing emergency services, b) impaired access to homes and businesses; c) lost economic activity; and d) damage to roadway infrastructure.
The DuPage County Department of Transportation analyzed the traffic effects of road/lane closures within the watershed to gauge the impact of these closures on the transportation system. This was done using the County’s regional transportation model, which was manipulated to reduce traffic on the five roads affected by road closures, above, and rerouting that traffic onto other roads. The effects of the road closures on traffic volumes are shown on Figure 5-3, which illustrates that high traffic was diverted off of impacted roads such as IL Route 53 and Maple Avenue, and onto local road as well as onto I-355 and I-88. This analysis demonstrates that the regional transportation system displayed resiliency by maintaining overall functionality. However, the flood did result in longer travel times, increased vehicle miles traveled, and high traffic volumes on some local road. In addition, homes and businesses in the immediate vicinity of the road closures were not accessible.
84
Figure 5-3: Traffic Effects of Road Closures 5. Land Use, Demographics and Transportation
5.3.2. Proposed Transportation Projects The Illinois State Tollway Highway Authority (ISTHA), the Illinois Department of Transportation (IDOT), the DuPage County Division of Transportation (DuDOT), and the local municipalities are each responsible for the construction, repair, and reconfiguration of their respective roadways. At this time, the following construction, repairs, or reconfiguration are ongoing or proposed (2015-2020) for roads located within the East Branch DuPage River watershed as shown in Exhibit 21.
• Intersection reconstruction of Illinois State Route 53 at Illinois State Route 56 (IDOT) • Intersection reconstruction of Illinois State Route 53 at Parkview Boulevard/Surrey Land (IDOT) • Culvert replacement at Illinois State Route 53 and Glencrest Creek (IDOT) • Phase II engineering of Illinois State Route 53 from Illinois State Route 64 to St Charles Road • Resurfacing of United States Highway 34 from Raymond Drive to I-355 (IDOT) • Resurfacing of Illinois State Route 38 from Bryant Avenue to Finley Road (IDOT) • Resurfacing of Illinois State Route 56 from Naperville Road to Illinois State Route 53 (IDOT) • Resurfacing of Illinois State Route 56 from Finley Road to Highland Avenue (IDOT) • Resurfacing of Illinois State Route 64 from Gary Avenue to Illinois State Route 53 (IDOT) • Removal and reconstruction of the Four Lakes Bridge over the East Branch DuPage River (Village of Lisle) • Removal and reconstruction of the Hill Avenue over the East Branch DuPage River (Village of Lombard) • Reconstruction of the intersection of Illinois State Route 53 and Madison Street (Village of Lombard) • Reconstruction of Crescent Boulevard between Park Boulevard and Riford Road (Village of Glen Ellyn)
85
6. Watershed Problems & Opportunities 6.1. Water Quality Problems and Opportunities Data is currently being analyzed. 6.2. Flooding and Flood Resilience Issues Flooding impacts residents of this watershed over a range of scales. The most severe impacts occur as a result of overbank flooding along the waterways, however, there are also impacts in areas that are isolated and away from these waterways. Any solutions that are be implemented in the watershed will have benefits, potential impacts and potential opportunities. A solution such as removing a restrictive structure or increasing storm sewer conveyance may solve one problem while inadvertently worsening a downstream problem. These simple projects must be evaluated at the largest scale to ensure that proposed actions increase flood resilience and do not inadvertently relocate risk. In this watershed, relocated risk is most likely to find its way to the most vulnerable populations with the highest unmet needs.
Potential solutions must be comprehensively evaluated for the immediate benefits, future benefits as well as potential foreseen impacts or missed opportunities. Historically, solutions that are actually implemented have well defined benefits that provide the incentive for action. These improvements are typically implemented by a local unit of government seeking to improve the quality of life for its constituents. Jurisdictional boundaries provide a limitation to the creativity that can be employed for implementing solutions. It is simply too complex for a municipality to look outside its boundaries for potential solutions. Only a broader reaching entity can help set policy and identify projects outside of municipal “silos” to provide greater benefits.
6.2.1. Types of Flooding and Flood Damages in the Watershed 6.2.1.1 Overbank Flooding Overbank flooding is characterized as water overflowing the banks of an open channel such as a creek, stream or waterway. Generally the areas affected by overbank flooding are typically associated with FEMA and regulatory floodplains denoted on Flood Insurace Rate Maps (FIRMs) or other Regulatory Flood Maps. The waterway channel cannot contain the amount of water flowing at that time and as a result, water surface elevations increase to overtop the tops of the channel banks in order to have more area to flow downstream. Overbank flooding is highly prevalent throughout DuPage County during larger storm events and damages can occur when development is too close to the channel banks or within the delineated risks associated with floodplain maps.
6.2.1.2 Levee Associated Flooding Levees are man-made structures typically constructed out of a variety of earthen materials to create an embankment which can contain or control floodwaters. Generally levees provide protection from flooding for a certain level of flood risk. Levees are typically designed to protect to a certain design storm event and typically have freeboard (additional height above the design storm elevations) to provide a factor of safety to the protection. Levees do not totally eliminate 86
6. Watershed Problems & Opportunities
the risk of flooding; rather they are designed to reduce the risk of flooding. Active maintenance and monitoring of a levee system is also important to further minimize risk and damage.
Overtopping of a levee occurs when the water surface elevation of the floodwaters exceed the top of the levee causing water to cascade into the area behind the levee and potentially causing extensive flooding and damages to areas designed to be protected. Overtopping can also exacerbate local flooding behind the levee because the volume of water overtopping the levee can exceed the capacity of the local stormwater drainage system serving this interior area. This is extremely important for the area of the East Branch DuPage River near the confluence with St. Joseph Creek since the levees in this area were originally designed for a 50-year storm event and have been frequently overtopped.
Local drainage and stormwater infrastructure provides drainage for the areas behind the levees. These systems typically need to have systems to prevent floodwaters from the waterway coming through the local drainage system and flooding the area protected by the levee. These outlets to the waterway typically consist of sewers or culverts with backflow preventers/flap gates, pump stations to pump water above the levee and out to the waterway, or some combination. When these local interior drainage systems are inadequate to convey stormwater runoff from their tributary areas, there can be local flooding behind the levee which can cause nuisance flooding, damages and road closures. Areas of Lisle have experience local drainage issues due to inadequate stormwater infrastructure behind the levee and due to exacerbation of the problem by levee overtopping.
Levees can also fail in a variety of ways causing sudden and dangerous amounts of floodwater to flow into and inundate the protected area behind the levee. Levees can fail by overtopping (floodwaters are above the crown or top of the levee), breaching (part of the levee gives way or opens up), or seepage (floodwaters flowing through the ground under or through the levee). These failures can happen quickly and without warning which is a serious and dangerous threat to the people, homes and businesses behind the levee. The levee along the East Branch DuPage River in Lisle had failed during the April 2013 flood event causing extensive damage.
6.2.1.3 Restrictive Culverts / Bridges Bridges, culverts and other hydraulic structures are typically designed to convey floodwaters while minimizing increases in flood stages upstream of the structure. Many of these structures along waterways are fairly old or constructed prior to current regulatory requirements. In many of these cases, the structures are inadequately sized to have an opening large enough to convey floodwaters safely through the structure. This causes flood waters to stage up on the upstream side of the structure and potentially cause roadway overtopping/flooding, overbank flooding, and possible damages to homes and structures. These impacts can extend up through the waterway for significant distance further impacting property and roads. Removing these structures and replacing them with larger structures may improve the areas upstream of the structure, but could impact areas downstream because of increased peak flood flows.
87
6. Watershed Problems & Opportunities
6.2.1.4 Flood Storage Facility Overtopping Flood storage facilities are typically composed of dry or wet bottom detention ponds, lakes or ponds, underground detention facilities, in-line channel storage, or other large flood control reservoirs. Current regulations in DuPage County require dedicated emergency overflows on these facilities to safely convey floodwaters downstream when these facilities are filled and overtopped to prevent damages to surrounding property. Many facilities have existed prior to current regulatory requirements and do not have safe overflow routes for large flood events. When these facilities are overtopped, floodwaters leaving the facility will flow along the ground surface until water reenters a drainage system or collects in a depressional area. These overtoppings may cause road closures and property damage.
6.2.1.5 Saturations of High Groundwater Areas There are areas that are low lying or near existing waterways where there might be the possibility of high groundwater elevations. These high elevations might be the result of a generally high groundwater table in the area, significant rainfall, or waterway flooding. High groundwater elevations can cause damages to homes, businesses and other structures if the groundwater seepage exceeds the capacity of the structure’s sump pumps. In addition, higher groundwater levels can have an impact on the infiltration of water into storm and sanitary sewer systems causing them to reach their capacity quicker than what was originally designed. High groundwater levels can also cause significant pressure on below grade building components causing problems and failures. The Valley View subdivision adjacent to Illinois Route 53 has significant groundwater issues associated with rainfall and East Branch DuPage River water levels.
6.2.2. Urban and Nuisance Flooding 6.2.2.1 Road Closures Road closures due to flooding can be a result of different issues including waterway overtopping bridges/culverts, insufficient storm sewer or roadway drainage systems, insufficient inlet capacity, inadequate pavement grades, or depressional / low lying areas along roadways. Water on the pavement can cause major issues for transportation. Emergency vehicles may not be able to traverse roadway flooding if it is too deep. Drivers may attempt to go through the roadway flooding with their vehicles, and have the vehicle get stuck or flooded out potentially requiring emergency rescue. Partial roadway flooding can cause drivers to lose control of their vehicle while driving through the flooded section. In addition, road closures can cause significant impacts to the economy due to loss of access to local businesses, traffic build ups which can cause delays and economic losses for businesses.
6.2.2.2 Drainage / Depressional Area or Nuisance Flooding Many stormwater infrastructure systems are only designed to serve small storm events and can be overwhelmed by quick and heavy thunderstorms or long and steady rainfall events. These areas are typically served by minor drainage systems comprised of small diameter storm sewers, ditches, yard drains or other drainage features. Large rain events can cause these local drainage systems to restrict water in low lying areas adjacent to roads, homes and businesses and can potentially cause flood damages to property. Many of these systems are located in the upper
88
6. Watershed Problems & Opportunities
sections of the watershed or subwatersheds and may have been installed prior to regulatory requirements or standard design practices. There are also areas with no drainage or stormwater infrastructure causing stormwater runoff to pond and flow overland in potentially damaging manners.
Throughout the area, there are also depressional areas which are low lying areas with no positive open channel or waterway outlet. Depressional areas can be drained by storm sewers or drain tiles. These areas can collect significant amount of stormwater runoff during large storm events and they generally have inadequate and undersized storm sewer systems. These areas can cause flooding which impact and damages properties and closes roads. Many communities in DuPage have documented the locations of these areas and associated flood damages to these areas. It is often the case, however, that these areas were historically wetlands and naturally stored this water. And this may offer opportunities to restore wetlands and riparian areas to better address this flooding.
Nuisance flooding can be general flood issues associated at the property level. Examples of what can cause nuisance flooding include poor lot to lot grading, settlement of the property’s ground surface, clogged catch basin and inlet grates, and other minor property drainage issues. This type of flooding can be associated with both new and old developments and can generally be improved by property level improvements and occasionally local drainage improvements such as improved sewer capacity or additional inlets.
6.2.2.3 Sanitary Sewer Backups Sanitary backups occur when the system where the home or structure’s sanitary sewer connects into mainline sewers becomes full and overwhelmed with floodwaters. This can happen with sanitary sewers due to significant infiltration of groundwater and interception of surface water. Septic systems can also become overwhelmed due to high groundwater and large amounts of infiltration. When the sanitary system becomes overwhelmed, sewage can back up into the house if the structure does not have overhead sewers or flood protection valves. Sanitary backups can cause extensive damage to property and belongings in addition to becoming a safety hazard due to mold and other bacteria developing and growing after a flood event.
6.2.3. Description of Major Flood-Affected Areas 6.2.3.1 East Branch DuPage River and St. Joseph Creek in Lisle The neighborhoods at the confluence of the East Branch DuPage River and St. Joseph Creek in the Village of Lisle, known as the River-Dumoulin area, have been affected repeatedly by flooding. Because of the frequency, extent and severity of these flood impacts, and the documented, unmet needs of both the fifty-year-old levee system and over 300 damaged or flood-prone homes in the area, this area is considered to be the Most Impacted-Most Distressed (MIMD) area in the East Branch watershed. Damaging flooding comes from a variety of sources, including:
• Locally-generated stormwater runoff backing up behind the levee system, • High floodwater overtopping the existing levee, • Overbank flooding from the East Branch DuPage River and St. Joseph Creek, 89
6. Watershed Problems & Opportunities
• Sanitary system backups, and • Flood water overflows diverting to localized depressional (i.e. low-lying elevation) areas.
During from the April 2013 storm event, Lisle was hit with drastic flooding in the areas adjacent to the river and behind the levee that highlighted the need for a multi-pronged response to prevent and respond to flooding and associated damages. The current levee system protecting the River-Dumoulin area was originally constructed in the 1960s, and was designed at the time to provide protection for up to a 50-year flood event. Since the levee’s construction, the area has experienced exceptional flooding that overtopped the levee roughly once each decade. The levee overtopped or breached in 1972, 1987, 1996, twice in 2008, and most recently in April 2013. During this last event, the levee system, which has settled and suffered from improper maintenance over time, was damaged and broke, causing widespread damage and impacts to homes, businesses and roadways in Lisle and Downers Grove.
The levee break in 2013 and subsequent damage to homes highlighted the significant unmet needs related to recovery from and resilience to flood events. Within the River-Dumoulin area, there are more than 223 homes identified by DuPage County that meet flood-prone criteria and are subsequently eligible for purchase under the County’s buyout program. Much of this area is low to moderate income housing. FEMA also has reported an additional 87 repetitive loss structures in DuPage County that meet their substantive damage threshold. Under FEMA’s National Flood Insurance Program (NFIP), a majority of these homes meet the 50-percent damage threshold and therefore cannot be repaired. The other homes have incurred significant damage and still have unmet repair needs. Finally, while the Village of Lisle and DuPage County have worked with the Hazard Mitigation Grant Program (HMGP) and CDBG-DR funding programs to attempt to repair/floodproof or buy out these properties, the Village of Lisle still has 25 properties in place that were damaged by the April 2013 flood but have not been repaired and floodproofed, or purchased for demolition.
Taken together, the condition of the levee, vulnerability of housing to flood damage, proportion of older and in some cases lower-income householders described in Section 3, and challenges completing repairs and buyouts combine to yield the “Most Impacted/Most Distressed” classification of this area. In its current, inadequate condition, the levee system will continue to impact the community during flood events due to the April 2013 failure and the overall inadequacy of the system. Many flood control and levee studies have been completed highlighting the need for additional flood protection, maintenance, improvements, buyouts, flood proofing, and other resiliency measures. DuPage County did construct four pumps stations in this area in 2007 to improve local drainage behind the levee. However, associated improvements necessary to improve local drainage behind the levee could not be constructed due to the difficulty and expense involved in obtaining easements from private property owners.
Another major issue affecting the cost, timing and feasibility of future improvements in this area also relates to private property easements. For most of its length, the levee system is located on private property. Although easements were proposed in the original design plans, neither title to the properties nor easements were acquired when the levee was constructed in the 1960s. 90
6. Watershed Problems & Opportunities
Most of the levee remains private property, which limits the access available to the County, Lisle or other government entities. With limited access and a lack of clear levee ownership and responsibility, the levee has fallen into disrepair, settled, and failed. A May 2013 memorandum noted that the levee had significant erosion, signs of overtopping, potential piping and seepage, and failure. Another report, the East Branch DuPage River Levee Study, completed in 2012 conducted a detailed levee assessment including soil borings. This report found that the existing levee system was constructed of structurally unsuitable material and was in dire need of maintenance. Recommended improvements included significant reconstruction or retrofits to have the levee meet standard design practices.
In addition, the levee system generally has undesirable woody vegetation, animal burrows and other miscellaneous structures (i.e. power poles, fences, stairways, piers and other vegetation) in or on the levee footprint. These uses can cause undermining of the flood protection that the levee provides and should be removed.
6.2.3.2 St. Joseph Creek in Downers Grove and Westmont St. Joseph Creek has been a source of flooding including overbank flooding, restrictive bridges/culverts, storage facility overtopping, high groundwater, road closures, depressional areas, inadequate stormwater infrastructure and other nuisance flooding. The Villages of Downers Grove and Westmont have been proactive in studying existing flood issues and documenting them through a variety of reports, watershed plans, flood control plans, and project prioritization plans. Damages from flooding in these areas include home, business and property damage as well as road closures. In addition, many areas are in need of significant stormwater infrastructure improvements and retrofits to improve inadequate stormwater conveyance and provide safe passage of overland flood waters during large storm events. The various reports and plans documenting the existing stormwater issues and in some cases, potential improvement opportunities, are provided in the references section and are available on the Village’s website or in their offices.
6.2.3.3 East Branch DuPage River through Unincorporated Areas Illinois Route 53 between Illinois Route 56 (Butterfield Road) and Park Boulevard has been a subject of significant overbank flooding and high groundwater issues causing damages to homes and extended road closures. This area has also been known as Valley View. Several flood control plans have been prepared for this area to analyze damages and recommend solutions to minimize the risk of flooding and road closures. DuPage County has previously purchased buyout eligible homes within the floodplain and is currently working with IDOT to relocate Illinois Route 53 onto the purchased properties and raise it above flood stages to minimize the risk of road closures. However, there still are property acquisitions required to fully complete this project. In addition, the Valley View area has been subject to high groundwater levels due to stormwater runoff and East Branch DuPage River flood stages. A report was prepared to document the issues and recommend solutions for groundwater issues. At this time, no additional work is proposed for high groundwater levels.
The Morton Arboretum has experienced flooding issues similar to the Valley View and Illinois Route 53 area. Overbank flooding and high groundwater levels have caused road closures and 91
6. Watershed Problems & Opportunities
extensive damage to the Arboretum’s facilities. They have developed several recommendations to minimize the risk of future flooding including additional sump pump systems and groundwater flow diversions on-site.
6.2.3.4 East Branch DuPage River in Glen Ellyn and Lombard Description of flooding is being prepared.
6.2.3.5 Lacey Creek Similar to the problems in St. Joseph Creek, Lacey Creek and its tributary stormwater infrastructure has caused a variety of flooding issues documented by Downers Grove in their published reports and watershed plans.
6.2.3.6 Willoway Brook Several areas within the Willoway Brook subwatershed are subject to flooding due to inadequate stormwater infrastructure, depressional areas and storage facility overtopping. The City of Wheaton has conducted and is currently completing several stormwater studies and plans in order to assess flood issues and develop potential projects. A watershed plan was developed by DuPage County in 1985 and evaluated and recommended stormwater infrastructure improvements. However, this plan is most likely out-of-date and would require significant updates and analysis to develop up to date flood assessments and alternative analysis.
6.2.3.7 Armitage Creek Description of flooding is being prepared.
6.2.4. Problem Areas Identified by Watershed Stakeholders Significant historical flooding within the East Branch DuPage River has occurred at several locations that have been well documented by DuPage County and municipalities. Major flooding in the watershed has generally been a result of overbank flooding, high groundwater levels during flood events, local drainage backups behind levees, high flood waters overtopping existing levees, levee failure, flood storage overtopping, sanitary backups, depressional areas and inadequate stormwater conveyance systems.
The many types of flood-related problems were illustrated vividly in the April 2013 flood event in the East Branch watershed. The April 2013 flood event was a longer duration storm event covering a wide area of northeastern Illinois which ultimately resulted in a high volume of stormwater runoff overwhelming the conveyance capacity of local (i.e. storm sewers, ditches, culverts) and regional (i.e. streams and rivers) systems. In addition, the high volume of stormwater runoff caused many detention and retention facilities to fill to capacity and in many cases, overtop and direct large amounts of flow downstream. Significant flooding also caused extended road closures of local streets, County routes and State routes impacting emergency services, evacuation routes, and residential and business traffic. DuPage County received between approximately 5.5 to 7 inches of rainfall on ground that was already fairly well saturated from prior rain and snowmelt. The magnitude of this event makes it a useful reference point for reporting problems in a “worst-case” event.
92
6. Watershed Problems & Opportunities
During the initial phase of the development of this plan, DuPage County hosted several stakeholder coordination and input meetings on the East Branch Watershed Plan and associated processes. During these meetings, stakeholders were asked to identify problem areas within the watershed. Additional discussion on data collection is detailed in Section 3.2. Problems were reported through a variety of means including submitting completed questionnaires, providing existing watershed and flood control plans, providing maps/data, and other means. The problem areas identified were compiled into nine main problem types and are listed in the below table and shown on Exhibit 22.
In addition, 911 and other emergency calls during and after the flood event were compiled by the DuPage County Office of Homeland Security and Emergency Management. These calls were mapped and a “heat map” was prepared to ascertain major areas impacted by flooding. This mapping effort combined with other problem areas identified by the stakeholders provided an easy to understand visual understanding of major flood impacted areas in the watershed. This map is provided in Exhibit 20.
6.2.5. Health and Wellbeing Impacts Flooding has the potential to negatively impact the health and wellbeing of residents. Contamination of groundwater wells and mold growth in housing structures are two health issues that may result from flooding.
Floodwater intrusion to groundwater wells can be a source of contamination that can impact residents obtaining potable water from private water wells. After the April 2013 flood, the DuPage County Health Department tested 395 private well samples for residents who felt that their well may have been impacted by the flood. The majority of the samples came from Lisle, Westmont, and Villa Park residents. Of the initial samples that were received, approximately 32% of the sample tested positive for microbial contamination. Table 6-2 identifies the number of samples tested in the months following the April 2013 flood.
Table 6-2 Private Well Water Samples following April 2013 Flood
Month Number of Samples April 148 May 214 June 16 July 8 August 1 September 7 October 0 November 0 December 1 Total 395
93
6. Watershed Problems & Opportunities
Mold is another health issue that can result from flooding. Mold is a concern because of a variety of health impacts. For individuals allergic to mold, it can cause nasal congestion, throat irritation, coughing or wheezing, and eye or skin irritation. Immune-compromised people and people with chronic lung illness may get serious infections in their lungs from mold exposure. Indoor mold exposure has been linked with upper respiratory tract symptoms in otherwise healthy people and asthma symptoms in people with asthma. This issue can linger for an extended time after the flood, especially for low-income and elderly households that may not have the resources or the physical ability to deal with the aftermath. For example, two years after the flooding events of 2008 it was identified through outreach that there was an unreported unmet need, particularly among low-income and elderly households for repair and mold remediation and $200,000 of Illinois Disaster Assistance Program (IDAP) funds were spent to aid approximately 40 households. In the aftermath following the April 2013 flood event, it was anticipated that a similar unmet need would exist. In the DuPage County Action Plan for CDBG Disaster Recovery Funds, $300,000 is budgeted toward Rehabilitation/Mold Remediation to provide assistance to approximately 60 households. In order for as many individuals to be able to take advantage of the mold remediation assistance as possible, Spanish translations about the informational materials is needed in areas with higher Spanish-speaking populations.
94
6. Watershed Problems & Opportunities
Table 6-1 Problem Areas Identified by Stakeholders
Problem Type
ID
Bridge \
Municipality General Location Description Overbank Flooding Overbank /Failure Overtopping Levee behind LeveeLocal Drainage Restrictive Culvert Flood Storage Facility Overtopping Groundwater High Closure Road / Other Local Drainage Nuisance / Depressional Backups Sanitary EBE2-01 Uninc. 2nd St Overbank flooding and X X DuPage between overtopping of Main St and Main and Forest Forest EBE2-02 Uninc. Glenrise Overtopping of Glenrise Ave X DuPage Ave EBEB-01 Lisle River Drive Local drainage through levee X X X X X X Area north through culverts with flap gates of Ogden and a pump station. Ponding Avenue occurs due to insufficient local drainage to pump station. Levee is overtopped frequently. EBEB-02 Lisle Dumoulin Local drainage through levee X X X X X X Ave north of through culverts with flap gates Ogden and a pump station. Ponding Avenue occurs due to insufficient local drainage to pump station. Levee is overtopped frequently. EBEB-03 Lisle River Drive Local drainage through levee X X X X X X and through culverts with flap gates Burlington and a pump station. Ponding Avenue occurs due to insufficient local drainage to pump station. Levee is overtopped frequently. EBEB-04 Lisle Dumoulin Local drainage through levee X X X X X X Ave and through culverts with flap gates Burlington and a pump station. Ponding Avenue occurs due to insufficient local drainage to pump station. Levee is overtopped frequently. Also subject to diverted overflow from St. Joseph Creek through IL 53 viaduct and from the south from the BNSF viaduct EBEB-05 Lisle IL 53 south Levee overtopping. Sanitary X X X of BNSF system full and causing backups viaduct
95
6. Watershed Problems & Opportunities
EBEB-06 Lisle IL 53 Extended roadway closure due to X X X (Warrenville flooding Road to Maple Avenue) EBEB-07 Lisle Maple Extended roadway closure due to X X Uninc. Avenue (at flooding DuPage East Branch DuPage River) EBEB-08 Uninc. IL 53 (IL 56 Extended roadway closure due to X X DuPage to Park flooding Blvd) EBEB-09 Uninc. IL 53 at Overbank flooding causing X X X DuPage Valley View additional high groundwater (between IL levels and road closures 56 and Park Blvd) EBEB-10 Glen IL 53 north Overbank flooding X Ellyn of IL 38 to Uninc. east of I-355 DuPage EBEB-11 Uninc. Morton Overbank flooding and high X X DuPage Arboretum groundwater EBEB-11 Lisle Four Lakes Roadway overtopping closing all X X Complex entrances to facility EBEB-12 Bloomin Indian Lakes General flooding and roadway X X gdale area flooding EBEB-13 Glen Riford Ave Lake Ellyn overtopping and X X X Ellyn and Oak St flooding area EBEB-14 Glen Perry’s Pond Flooding impacting surround X Ellyn areas and upstream areas EBEB-15 Lombard Greenfield Overtopping of Terrace View X X X X X to Sunset, Pond and associated overbank west of flooding of tributary. Inadequate Main St and storm sewer infrastructure. High east of groundwater issues causing Elizabeth St basement flooding and sewage backups EBEB-16 Lombard Windsor Overbank flooding with X X Ave area inadequate stormwater from infrastructure and depressional Broadview areas to Elizabeth and Grove St EBEB-17 Lombard St. Charles Combined sewer area in Lombard X X to the north, with significant sewage backups, East Branch inadequate stormwater divide to the infrastructure and depressional East, Wilson areas to the south, Edison to the west
96
6. Watershed Problems & Opportunities
EBEB-18 Lombard Hickory St Inadequate stormwater X to the north, infrastructure and depressional Main St to areas the east, Edison St to the west, Madison to the south EBEB-19 Glen Hillside and Depressional area with flood X Ellyn Bryant damages EBGL-01 Glen Fairview Depressional area with flood X X Ellyn and Main St damages and roadway flooding EBGL-02 Glen Turner west Depressional areas with sanitary X X Ellyn of Regent backups EBLA-01 Downers Black Oak Overflow from inadequate local X Grove Drive stormwater infrastructure between Saratoga and Candlewood EBLA-02 Downers Downers Inadequate stormwater X Grove Dr., Virginia infrastructure and undefined St, Seeley overflow paths Ave, 40th St EBLA-03 Downers Elm and Inadequate stormwater X Grove Earlston infrastructure and depressional between areas Ogden Ave and 41st St EBPR-01 Downers Puffer south Inadequate stormwater X Grove of 61st St infrastructure and depressional areas EBPR-02 Woodrid 63rd St and Overbank flooding along park in X X ge Winston Dr. open channel EBSJ-01 Lisle IL 53 and Overbank flooding and road X X X Lacey Ave closures. Levee overtopping and road closures with overflow diversion to other areas. Similar to Problem ID EBDR-2. EBSJ-02 Downers BNSF RR, Long restrictive culvert on private X X Grove Douglas property causes upstream Ave, Rogers flooding St EBSJ-03 Downers Hill St and Culvert with restrictive grate X X Grove Grand Ave accumulates debris and causes to 55th St flooding EBSJ-04 Downers Deer Creek Restrictive culvert at Fairview, X X Grove area - 56th overbank flooding through Westmon St and overland flow routes t Fairview Ave to 59th St and Williams St
97
6. Watershed Problems & Opportunities
EBSJ-05 Downers Maple Ave Long restrictive culvert with X X X Grove and Blodgett storm sewer connection from Ave depressional area EBSJ-06 Downers Pershing Inadequate stormwater X Grove between infrastructure and depressional Ogden and areas Grant EBSJ-07 Downers Grant St and Localized residential issues X Grove Downers Ave EBSJ-08 Downers Washington Inadequate stormwater X Grove St south of infrastructure and depressional Westmon Ogden Ave areas t EBSJ-09 Downers Drendel Roadway flooding with X X Grove Road south inadequate stormwater of infrastructure and depressional Indianapolis areas EBSJ-10 Downers Chase Ave Inadequate stormwater X X Grove between infrastructure causing road Haddow and flooding and property flooding Warren EBSJ-11 Downers Walbank Historical flooding at X X Grove north of depressional area with bypass Warren flow from steep tributary area EBSJ-12 Downers Prairie Depressional area flooding due to X X Grove between inadequate stormwater Forest and infrastructure Prince EBSJ-13 Downers Deboldt / Inadequate stormwater X Grove Linden / infrastructure and intersection Gierz EBSJ-14 Downers Hitchcock Depressional area with no known X Grove between outlets Cornell and Glenview EBSJ-15 Downers Middaugh Inadequate stormwater X Grove and infrastructure and depressional Jefferson areas EBSJ-16 Downers Lyman Inadequate stormwater X Grove between infrastructure Kenyan and Blanchard EBSJ-17 Downers Francisco at Inadequate stormwater X Grove Burlington infrastructure EBSJ-18 Westmon Liberty Inadequate stormwater X X t Park, Adams infrastructure and depressional Uninc. St, Cass Ave areas. Detention pond DuPage and Ogden overtopping flooding Ave to Park neighborhood and 40th EBSJ-19 Westmon Richmond Depressional storage areas X t and Grant flooding
98
6. Watershed Problems & Opportunities
EBSJ-20 Westmon Roslyn and Depressional storage areas X t Burlington flooding EBWI-01 Wheaton Williston Inadequate stormwater X and infrastructure and depressional Evergreen areas EBWI-02 Wheaton Pershing Inadequate stormwater X from infrastructure and overland flow President to paths Prospect EBWI-03 Wheaton Brentwood Storage overtopping and X X and inadequate stormwater Briarcliffe infrastructure
6.3. Land Use Plans, Policies & Practices Information on how the land is managed in a watershed is helpful to identify both current control practices and potential targets for future management. This information not only will support the characterization of the watershed but also will be important in identifying current watershed sources, future management efforts, and areas for additional management efforts.
6.3.1. DuPage County Countywide Stormwater and Flood Plain Ordinance (DCCSFPO) The DCCSFPO contains detailed regulations for the protection of wetlands and floodplains, and for all stormwater management, and soil erosion and sediment control. It is one of the oldest (1st passed in 1991) and strictest countywide stormwater ordinances in the Chicago region and has evolved through 13 revisions to better address the flooding and stormwater issues of DuPage County. To help further guide regulation it calls for the development of watershed-specific plans, including for the East Branch DuPage River.
The DCCSFPO has been adopted as Appendix F to the DuPage County Stormwater Management Plan. The primary purpose of the DCCSFPO is to promote effective, equitable, acceptable, and legal stormwater management measures. Specific purposes include:
• Managing and mitigating the effects of urbanization on stormwater drainage; • Reducing the existing potential for stormwater damage to public health, safety, life, and property; • Protecting human life and health from the hazards of flooding and degradation of water quality; • Protecting and enhancing the quality, quantity, and availability of surface and groundwater resources; • Preserving and enhancing existing wetlands, buffers and aquatic environments, and encouraging restoration of degraded areas; • Controlling sediment and erosion in and from stormwater facilities, developments, and construction sites; • Preventing the further degradation of the quality of ground and surface waters; • Requiring appropriate and adequate provision for site runoff control, especially when the land is developed for human activity;
99
6. Watershed Problems & Opportunities
• Requiring that the design and evaluation of each site runoff control plan consistent with watershed capacities; • Encouraging the use of stormwater storage in preference to stormwater conveyance; • Lessening the taxpayers' burden for flood-related disasters, repairs to flood- damaged public facilities and utilities, and flood rescue and relief operations; • Meeting the Illinois Department of Natural Resources, Office of Water Resources' Floodway permitting requirements; • Making federally subsidized flood insurance available to individual communities and for property throughout the County; • Complying with the rules and regulations of the National Flood Insurance Program; • Encouraging cooperation between the County, communities, and other governmental entities with respect to floodplain and stormwater management; • Requiring cooperation and consistency in stormwater management activities within and between the units of government having stormwater management jurisdiction; • Restricting future development in the floodplain to facilities that will not adversely affect the floodplain environments or adversely affect the potential for flood damage; • Incorporating water quality and habitat protection measures in all stormwater management activities within DuPage County; • Requiring regular, planned maintenance of stormwater management facilities; • Encouraging control of stormwater quantity and quality at the most site-specific or local level; • Allowing the use of simple technologies whenever appropriate and realistic, but requiring the use of more sophisticated techniques when necessary to ensure the adequacy of stormwater controls; • Providing a procedure by which communities throughout the County may petition the Committee to implement enforce the provisions of this Ordinance.
The DCCSFPO is currently providing some measures of resiliency and flood protection across the East Branch DuPage River watershed. The following benefits of the current ordinance have been identified by County staff.
• Protections for wetlands following a general avoidance, minimization, and mitigation sequencing mirroring the federal wetland protections under the Clean Water Act, but also providing protection for isolated wetlands not currently under federal jurisdiction. • For any impact, wetlands must be replaced in the same major watershed (e.g. East Branch). • Wetland compensatory mitigation ratios range from 1.5:1 for standard wetlands to 3.0:1 for high quality wetlands. • Wetland buffers and floodplain functions must be replaced if impacted. • Compensatory storage is required for floodplain impacts at a 1.5:1 replacement ratio.
100
6. Watershed Problems & Opportunities
• Required permanent stormwater volume control/water quality BMPs such as wetland basins, infiltration practices, and stormwater detention for developments that exceed certain thresholds. • Currently mapping most wetlands in DuPage County through a grant from the EPA. The mapping effort will help regulators and property owners to more easily identify where wetlands are likely to occur. Better maps may help developers and property owners know about wetlands earlier in the planning process so that they are more easily avoided and make inadvertent impacts less likely. • Currently updating FEMA flood maps as a Cooperating Technical Community with FEMA. Accurate maps are needed as a source of information for property owners, regulators and developers to reduce and prevent future flood damages. The new maps will reflect changes in land use, topography, hydraulic structures, and modeling technology since the original FIRM effective dates. • Sediment and erosion control is required during construction.
All of these are positive measures contributing to the current level of resiliency in the East Branch DuPage River watershed. Additional items that could be addressed or considered in this Watershed Plan and/or in future revisions to the DCCSFPO for this watershed to improve resiliency and flood reduction include:
• Develop comprehensive a watershed plan for the East Branch and for its tributaries. The DCCSFPO requires applicants and regulators to consult watershed plans during the development planning phase and calls for the development of detailed watershed plans across the County. A watershed plan pointing out key issues allows regulators to ask for specific development features that may help solve flooding or other stormwater problems on a watershed scale incrementally. • Increase watershed-specific wetland, buffer and riparian protections. • Encourage/incentivize establishment and protection of broader native floodplains. • Lower thresholds that trigger requirements for stormwater BMPs where local drainage problems exist. • Provide for more regular stormwater and compensatory storage basin inspections for loss of volume and other performance issues. • Encourage owners/managers of older open water stormwater basins to retrofit to wetland bottom without loss of storage to provide additional benefits such as improved water quality, increased evapotranspiration, more resilient habitat, reduced geese/algae/sediment/erosion issues, and increased dissolved oxygen. • Protect trees in the watershed – mature trees uptake between 65 and100 gallons of water per day during the summer (Akbari, 1992; Thomas, 2000; Cermak et. al., 2000), a tree crown can store about 50-100 gallons per tree during a rain event (USDA Northeast Community Tree Guide); the uptake of soil water by tree roots increases the available water storage potential in the soil. • Require that wetland compensatory mitigation from development impacts be provided in the same tributary watershed rather than just within the East Branch basin.
101
6. Watershed Problems & Opportunities
• Seek out opportunities to install subdivision-scale volume control and pollutant control permanent best management practices or wetlands. • Provide for better enforcement of sediment and erosion control and BMP/runoff basin conditions. • To improve water quality, limit the use of salt and fertilizer near wetlands, buffers, waterways, and floodplains. • Subsidize or operate the maintenance and monitoring of basins and BMPs countywide. • Require development to enhance the functions of wetlands, buffers and riparian environments through native plant management. More diverse native plant communities can increase infiltration, evapotranspiration, and the assimilation of pollutants. They are also more resilient to climate change, pests, and other environmental stressors. • Preserve the infiltration capacity of native existing soils where possible by protecting them from unnecessary compaction. This can reduce runoff volume and pollutants. • Make paying a fee in lieu of providing site-specific BMPs harder or more expensive to encourage better on-site practices. • Examine sizing of stormwater BMPs based on the tributary area instead of the new impervious area which may reduce sediment and pollutants in the watershed. • Require long term inspections and maintenance on all stormwater runoff control, floodplain compensatory storage, and post construction best management practices. Verify that restrictors are still in place and verify that volume is still being provided. • More enforcement of regulations and audits for communities enforcing the Ordinance • Prohibit snow from plowing to be dumped in wetlands, buffers, waterways, or floodplains-reduce sediment which decreases storage in wetlands and floodplain. • A new guidance document for the Ordinance to include an overhaul of the BMP manual-will increase education of the consulting and development community to encourage bringing special management areas into the process as early as possible. • Require development to size detention and BMPs for full future build-out potential • Develop sample or typical detailed design specifications for best management stormwater practices such as detention basins, volume control facilities, post construction best management practices, and native plantings. • Subsidize the design, implementation, maintenance, and monitoring of public and private BMPs, including both voluntary and required facilities. The County could offer a tax or permit fee breaks for installing BMPs that reduce runoff. An incentive system may encourage more voluntary BMPs to be constructed, and maintenance support will keep them functioning providing greater resiliency in the watershed. • Buyout wetland and floodplain properties that are in private ownership and have not been developed. Preserve properties that have not yet been developed and are part of our valuable network of wetlands and floodplains. Preservation and restoration of these areas is many times more cost effective than building a facility of the same size that provides the same benefits. • Education, training and outreach for municipalities, professionals, realtors, property owners, and children on:
102
6. Watershed Problems & Opportunities
Flooding causes and regulations Wetland, buffer, and riparian benefits and protections Water quality in the watershed Sediment and erosion control Bringing wetlands, buffers, and floodplain into the development process before a property is purchased to increase chances of avoidance. A PR campaign to make owning a healthy rain garden, wetland, or rain collection system trendy. Moving forward to provide greater resiliency and flood protection, it will be important to balance new project ideas against their impacts to the overall resiliency of the watershed. For instance, floodproofing utilities and buildings may impact or degrade wetlands and riparian environments. Both are important and the benefits and costs (trade-offs) should be weighed and impacts minimized as projects move forward.
6.3.2. Municipal Plans & Initiatives Additional analysis is being completed.
6.3.3. Planning for Natural Areas 6.3.3.1 DuPage Natural Areas Master Plan In 2013, efforts began to coordinate the efforts of all local and regional open space organizations in the acquisition or protection of property that will benefit and improve the quality of life for the residents of DuPage County. The principal goals of the plan were to: identify and prioritize parcels of property in DuPage County that will provide trail and greenway linkages, expand existing open space properties, buffer existing open space, and protect forests, woodlands, prairies, wetlands, watersheds, streams, and river corridors; identify natural areas that will promote protection and preservation of endangered and threatened wildlife and plant species; and create a plan that various agencies in DuPage County can use to protect the identified remaining open space, as well as foster cooperation and partnerships in implementing the plan over time.
The purpose of this open space and natural areas plan is to coordinate the efforts of local and regional open space organizations in the acquisition or protection of property that will benefit and improve the quality of life for the residents of DuPage County. Specifically it seeks to identify and prioritize parcels of property in DuPage County that will provide trail and greenway linkages, expand existing open space properties, buffer existing open space, and protect forests, woodlands, prairies, wetlands, watersheds, streams and river corridors. It provides a plan that various agencies and organizations in DuPage County can use to protect the identified remaining open space, and foster cooperation and partnerships in implementing the plan over time. Implementation of this plan over time, will protect remaining pieces of DuPage County’s natural heritage, and provide better resiliency in the face of a changing climate. While it is not centered on stormwater and flood control, these pieces of existing, natural green infrastructure will provide stormwater, flood control, and water quality benefits in addition to the biodiversity and recreational goals.
103
6. Watershed Problems & Opportunities
This county-specific open space or green infrastructure network plan can provide an important framework for the details of an East Branch DuPage River watershed plan by identifying existing protected open space, and remaining privately owned open space that may provide opportunities for increased watershed resiliency.
6.3.3.2 Chicago Wilderness Green Infrastructure Vision In 2004, the Northeastern Illinois Planning Commission (NIPC, now part of CMAP) completed a Green Infrastructure Vision (“GIV 1.0”) for the Chicago Wilderness (CW) region. This product identified large Resource Protection Areas (RPAs) and recommended protection approaches for each, including additional land preservation, ecological restoration, or development restrictions. These recommendations were based primarily on charrettes that distilled the professional judgment of natural resource experts within Chicago Wilderness. GIV 1.0 resulted in a final report containing the recommendations, as well as, several printed maps and GIS data representing the RPAs. In 2012, CW undertook a refinement of the previous work that was intended to classify and characterize important resources in a more analytically robust manner, as well as, to define ecological and human connectivity needs, and provide enhanced information to support conservation and development decisions. The Green Infrastructure Vision has often been described as a visual representation of the Chicago Wilderness Biodiversity Recovery Plan, and the refinements of GIV completed in 2012 were meant to help further advance the broad conservation agenda established by the Biodiversity Recovery Plan. The main products of the revised GIV project are derived GIS datasets that describe and characterize the regional green infrastructure or ecological network.
The GIV covers the Chicago Wilderness ecoregion which includes counties in Wisconsin, Illinois, and Indiana, with a small portion of Berrien County, Michigan. The ecoregion includes some or all of the Metropolitan Planning Organization (MPO) boundaries of CMAP, the Northwestern Indiana Regional Planning Commission (NIRPC), and the Southeastern Wisconsin Regional Planning Agency (SEWRPC), along with portions of additional outlying counties in Illinois and Indiana.
The primary purpose of the GIV is to identify a regionally important network of land and water that is critical to protect and restore to the conserve biodiversity of the region. This regional green infrastructure network was developed for the Chicago Wilderness region area using the core-hub-corridor approach. The building blocks of the network are “core areas” that contain well-functioning natural ecosystems that provide high-quality habitat for native plants and animals. By contrast, “hubs” are aggregations of core areas, as well as, nearby lands that contribute significantly to ecosystem services like clean water, flood control, carbon sequestration, and recreation opportunities. Finally, “corridors” are relatively linear features linking cores and hubs together, providing essential connectivity for animal, plant, and human movement.
The current revised GIV retains the emphasis on protecting biodiversity from the original GIV, but it also seeks to address a broader range of issues and provide a wide array of benefits. Continuing the original approach, the current GIV gives “a high priority… to identifying and preserving important but unprotected natural communities, especially those threatened by 104
6. Watershed Problems & Opportunities development, and to protecting areas that can function as large blocks of natural habitat though restoration and management.” Thus GIV addresses the following conservation strategies:
• Creation of large preserves: The GIV identifies the largest blocks of unfragmented landscapes based on ecological resources rather than property boundaries. • Creation of community mosaics: The GIV assembles blocks of forest/woodlands, prairie/savanna, wetlands, and aquatic systems into hubs of multiple landscape types to reflect the importance of a mix of habitats that support biodiversity. • Protection of priority areas, especially remaining high-quality sites: The GIV incorporates the best available data on high quality natural heritage sites, natural areas, and important bird areas regardless of the size of the site and current protected status. • Protection of any large sites with some remnant communities: The GIV includes adjacent compatible land cover around known remnant communities to buffer and hopefully expand them over time. • Protection of land that connects or expands existing natural areas: The GIV uses functional connectivity to link core areas and hubs together and identify potential locations for restoration. • Expansion of public preserves, acquisition of large new sites, and/or protection through the actions of private land owners where possible: The GIV can be used to identify gaps in protection and opportunities for private land stewardship that advances the goals of the Biodiversity Recovery Plan.
This regional green infrastructure network also provides multiple benefits. At its broadest, landscape- scale green infrastructure provides important ecosystem services like clean air and water, critical plant and animal habitat, and wildlife migration corridors along with compatible working landscapes. At the regional scale, green space can help protect water quality and help ensure the availability of drinking water. Green infrastructure can also provide key recreational areas that link people to natural lands and facilitate the use of transportation modes other than automobiles to reach key community assets. At the site scale, green infrastructure enhances neighborhoods and downtowns through environmentally-sensitive site design techniques, urban forestry, and stormwater management systems that reduce the environmental impact of urban settlements and increase community resiliency. All of these scales of activity can be linked together and can ensure resiliency in urban, suburban, and rural areas of a region. Green infrastructure can be implemented at many different scales. Finally, as surveys of conservation organizations by the Land Trust Alliance have documented, producing a strategic conservation plan is associated with a dramatic increase in the pace of land conservation (Amundsen, 2011).
The emerging consensus on climate adaptation planning is that well-defined spatial priorities are needed to facilitate adaptation for wildlife and ecosystem processes. This approach identifies those elements of the landscape most relevant to wildlife now, in the face of current threats, as well as, in the future as the climate changes, and it provides a spatial framework for climate adaptation planning relevant to land conservation efforts. At a landscape scale, the GIV network incorporates places where building resilience by conserving large habitat blocks and
105
6. Watershed Problems & Opportunities realigning corridors to build connectivity will ultimately help wildlife and people adapt to an altered climate.
The GIV groups landscape or cover types into the following groups for the purposes of mapping: prairie/grasslands/savannas, woodlands/forests, wetlands, streams/lakes/rivers, and urban- scale green infrastructure. Each group was mapping based on biologically based criteria coupled with best available data that provided local accuracy. All of the geospatial data has been made available to any potential users and partners. Several local communities, 3 Illinois counties, and some other localities have used the GIV to create their own stepped-down green infrastructure plan that includes local priorities and features that could not be mapped at a regional scale. These plans are then used to guide conservation and land planning in those localized areas. It is the intent that the GIV can be used as a tool for any local planning, including municipal revisions to comprehensive plans. Considering the regional and watershed-scale green infrastructure along with site and neighborhood scale constructed green infrastructure practices can greatly enhance resiliency.
In 2014, CMAP contracted with the Conservation Fund to complete an economic valuation study of the ecosystem services provided by the GIV within the 7-county area they serve. Ecosystem services are the collective benefits from an array of resources and processes that are supplied by nature. Forests, wetlands, prairies, water bodies, and other natural ecosystems support our existence. Since 2004, the GIV has served as a visual representation of the Chicago Wilderness Biodiversity Recovery Plan, but it also served as a spatial representation of the region’s ecosystem services. Only recently has it become possible to reliably estimate the contributions the GIV makes to human well-being and to measure the benefits that nature provides us for free. This economic valuation study provided a review and visualization of ecosystem service values for six ecosystem services within the CMAP 7‐county region: water flow regulation/flood control, water purification, groundwater recharge, carbon storage, native flora and fauna, and recreation and ecotourism. In addition, three additional ecosystem services were researched but did not have sufficient information to support visualization at the CMAP regional scale: air purification, microclimate moderation, and increases in property values.
According to analysis completed for this project, natural ecosystems contribute well more than $6 billion per year in economic value to the 7‐county CMAP region. In comparison, the gross domestic product (GDP) of the Chicago Metropolitan Statistical Area (which mostly overlaps the 7 counties) was $586 billion in 2013. And this estimate may undercount the total value since this estimate is only from ecosystem services that could be reliably measured, this total does not include any of the economic activity supported by the region’s recreation and ecotourism infrastructure, and did not measure contributions from Lake Michigan.
The Chicago Wilderness GIV is used every day by planners and decision makers at the local, state, regional, and federal levels to guide existing planning efforts and evaluate conservation and restoration opportunities that support preserving and managing the GIV network. The GIV can now help identify the most strategic locations for CMAP and its partners to implement the land conservation goals of the GO TO 2040 metropolitan Chicago comprehensive regional 106
6. Watershed Problems & Opportunities
plan. Specifically, GIV now provides an estimate of return on investment for conservation capital in different locations within the CMAP service area.
A recent study found that if the values of ecological services are considered, the benefits from conserving natural land gives a return on investment of at least 100 to 1. Using the GIV to estimate the monetized social benefit of conservation in comparison with the investments required to protect land is a scientifically valid and valuable product that will lead to increased awareness of decision makers and the general public regarding the importance and contribution of green infrastructure to the region’s quality of life and resiliency.
6.3.3.3 Morton Arboretum Plans The Morton Arboretum property contains 14 ponds and lakes, several seasonal drainageways, several wetland areas, and Willoway Creek, in addition to the main channel of the East Branch DuPage River. The Arboretum has been manipulating the landscape for their mission as an outdoor museum since the 1920’s, and in recent decades has undertaken several projects to improve the condition of the lakes and ponds. Drainage and flooding have also been issues addressed in various ways over the decades.
Drain Tile Investigation
In 2013-2014 the Morton Arboretum conducted a detailed drain tile investigation of their property. Their purpose was to locate all drain tiles throughout the property, assess their condition/function, consolidate all historic and current information into one geospatial database, and develop plans to improve the drainage system where needed to support their outdoor museum collections. The investigation revealed 18.4 miles of drain tile of which 14.9 miles were actively functioning, and 3.5 miles were inactive due to previous restoration projects. Of the functioning tiles, approximately 8.6 miles were clay tile, and 6.3 miles were plastic. There are also 0.8 miles of concrete stormwater pipes on the property. Drain tiles were found to both enter and exit the Arboretum property. The Arboretum has proposed a total of 29 drain tile improvement projects to ensure safety for people and equipment, reduce drainage liability, and improve the conservation value of the collections.
Visitor Center Parking Lot BMPs
A significant recent project undertaken by the Arboretum includes several aspects that altered and improved drainage and water quality entering the East Branch DuPage River, while improving the Arboretum’s visitor service capacity. In the 1990s the Arboretum created a new master plan which included a large new visitor center and several new gardens adjacent to it. The purpose was to increase visitorship from the general public and so this also necessitated a new larger parking lot adjacent to the river. Meadow Lake, which is adjacent to the Visitor Center and parking lot, was undergoing Illinois EPA Clean Lakes Program funded improvements. To provide good stewardship of the River and Meadow Lake, the Arboretum undertook the design and installation of a “green” parking lot, one of the first of its kind in the region. The parking lot was approximately 5 acres in size, needed to accommodate about 500 vehicles, and is located within the floodplain of the River. It was designed with significant
107
6. Watershed Problems & Opportunities
bioswales to provide filtration and infiltration of runoff, and used permeable, interlocking concrete pavers. Level spreaders, treatment wetlands, and other BMPs were also included in the design. Compensatory flood storage is provided within the void space of the aggregate base beneath the permeable paver parking lot. Ongoing efforts monitor and maintain the performance of this parking lot and drainage system designed to be an example demonstration project.
Section 206 Ecosystem Restoration Project
An ongoing, multiphased project affecting over 80 acres along the East Branch, the main channel of the East Branch, and Arbor Lake is funded through the section 206 Ecosystem Restoration program of the US Army Corps of Engineers, Chicago District. This project will include river bank stabilization, in-stream habitat features, recontouring the shoreline of Arbor Lake, and removing shoreline invasive plants on both the river and the lake. Portions of this project have been completed, while other parts are planned to begin during summer 2015.
Chicago Region Trees Initiative
Finally, the Morton Arboretum is leading a new effort called the Chicago Region Trees Initiative across the Chicago region, including the East Branch watershed. The premise is that our regional forest is a critical asset in need of protection. Trees clean the air and water, reduce flooding, improve property values, create habitat for wildlife, and provide significant social and health benefits. Invasive species, including buckthorn and honeysuckle, the death of ash trees due to emerald ash borer, and the lack of funding for proper tree care and attention are having significant impacts on the health and survival of our regional forest. The Chicago Region Trees Initiative (CRTI) is a unique and collaborative response to key issues facing trees across our urban landscape.
The Chicago Region Trees Initiative was established in 2013 as a collaboration of Chicago region partners working together to develop and implement a strategy that builds a healthier and more diverse urban forest by 2040. This strategy was developed based on findings from the Regional Tree Census produced in cooperation with the USDA Forest Service and The Morton Arboretum. A coalition of agency, industry, and community representatives are working together to expand the understanding of the value of the region's trees and to make meaningful tree and forest improvements in the region.
Ten key organizations form the leadership of CRTI: The Morton Arboretum, Openlands, The Nature Conservancy, the U.S. Forest Service, the U.S. Fish and Wildlife Service, Chicago Wilderness, the Illinois Landscape Contractors Association, the Cook County Forest Preserve District, the Metropolitan Mayors Caucus, and the Chicago Metropolitan Agency for Planning.
The overarching mission of CRTI is ambitious: to make a significant, measurable improvement to the regional forest and the lives of its inhabitants by the year 2040. The broad geographic scale and depth of the work will help the Chicago region establish a healthier forest. CRTI is setting actionable goals for canopy cover, species and age class diversity, and management expertise to create a more resilient forest. CRTI will establish these goals using baseline data of 108
6. Watershed Problems & Opportunities
forest composition and operational capacity of forestry programs collected by local and national forest researchers. CRTI will compile and analyze these data, including public and private tree inventories, regional tree census results, and LIDAR imagery. The information, planning, and implementation of the various goals of the CRTI will encompass the East Branch DuPage River and represents an ongoing effort that will improve watershed resiliency. 6.4. Watershed Jurisdictional Coordination Additional discussion is being prepared.
6.4.1. Roles and Responsibilities Additional discussion is being prepared.
6.4.1.1 DuPage County Stormwater Management Plan In 1989 DuPage County adopted the DuPage County Stormwater Management Plan. This plan provided the foundation for future watershed planning efforts, the DCCSFPO and water quality improvements throughout the county. It was established in recognition of the critical need to limit the reoccurrences of extensive flood damages within the County, and was implemented by the Stormwater Committee to reverse that trend. This plan responds to the opportunity inherent in State of Illinois P.A. 85-905, which authorizes regional stormwater management in northeastern Illinois counties. It also recognizes the integrated nature of the watershed system and the need to consider stormwater management planning on a watershed basis. This plan accomplished three main purposes. It consolidates the stormwater management framework throughout DuPage County into a united, countywide structure; sets minimum countywide standards for flood plain and stormwater management; and provides for countywide coordination for the management of stormwater runoff in both natural and manmade drainageways and storage.
In addition, this plan establishes standards for many aspects of County stormwater program, including Objectives and Policies; Watershed Plans and Flood Maps; Problems and Project Planning; Maintenance Programs; Regulatory programs; Facility and Local Data; Technical Guidance; Funding; and Implementation and Enforcement.
6.4.2. Policies and Regulations DuPage County has a comprehensive DCCSFPO that was based on the Management Plan (dated 1989). This DCCSFPO was first implemented in 1991 with several revisions and the last update in 2013. This DCCSFPO has helped the County improve localized flooding with restrictive detention requirements and a no-net loss policy for wetlands. By infiltrating more water at the source demonstrated benefits recognized by local communities. Once the County established itself within the region with a strong DCCSFPO it was recognized by other state and federal agencies as serious for stormwater management, resource protection and water quality. In 1996 the County received IDNR/OWR delegation to review for development and/or impacts within the floodway. With wetland protection the County was granted review authority by the USACE for all jurisdictional wetlands. Added to that delegation in 2009 was the IEPA 401 Water Quality Certification. These agency partnerships will help promote resource protection, reduce
109
6. Watershed Problems & Opportunities duplication of permitting efforts and provide better watershed decision making tools at the local level.
110
7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives 7.1. Existing Studies and Analyses 7.1.1. FEMA Flood Insurance Study (FIS) The current FEMA Flood Insurance Study (FIS) was published in March 2007 and provides a summary of potential flood risks generally associated with open waterways (i.e. rivers, streams, creeks, lakes, etc.) throughout DuPage County. The first FIS for DuPage County was originally published with an effective date of December 4, 1985. Since then, numerous updates to hydrologic and hydraulic model as well as other mapping updates have caused the FIS to be updated and republished for use. A Flood Insurance Study is used to document the existence and potential hazards of flooding throughout the study area. An FIS study is used in conjunction with FIRMs to illustrate the details and extents of flood hazard areas. These two sets of documents help with the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. The flood risk data is used to establish actuarial flood insurance rates for properties. The information provided in these documents also allows DuPage County to update floodplain regulations as part of the National Flood Insurance Program (NFIP).
For the East Branch, the current FIS utilizes hydrologic data and results from the USACE’s Chicago Metropolitan Study, DuPage River Basin published in 1974. The hydraulic data and results are based on the USACE HEC-2 modeling program as part of the HEC-2 Water Surface Profiles study published in 1976. A summary of the data sources and dates for the mainstem and its tributaries is provided in the table below with full references provided in the FIS. According to the FIS, other sources of flooding for smaller tributaries and FIRM areas noted as unnumbered Zone A have typically come from local studies or USGS Flood of Record Maps
Table 7-1 Summary of FIS Data Sources for Hydrologic and Hydraulic Analyses per the 2007 FIS
River Hydrology Hydraulics East Branch DuPage River HEC-1 HEC-2 Mainstem 1973 1976 (EBEB) Armitage Creek Regression Equations HEC-2 (EBAR) 1973 1973 Army Trail Road Tributary HEC-1 Backwater from EBEB only (EBAT) 1973 1976 Crabtree Creek Regression Equations HEC-2 (EBCR) 1973 1982 Tributary No. 1 Log-Pearson Type III HEC-2 (EBE1) 1976 1974 Tributary No. 2 HSPF FEQ (EBE2) 2001 2001 Tributary No. 3 HEC-1 Backwater from EBEB only (EBE3) 1973 1976 Tributary No. 6 Ratio of Lacey Creek HEC-2 111
7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives
(EBE6) 1976 Tributary No. 7 Log-Pearson Type III HEC-2 (EBE7) 1976 1976 Glencrest Creek Log-Pearson Type III HEC-2 (EBGL) 1976 1982 Glen Park HEC-1 Backwater from EBEB only (EBGP) 1973 1976 Lacey Creek HEC-1 HEC-2 (EBLA) 1973 1976 Prentiss Creek Log-Pearson Type III HEC-2 (EBPR) 1976 1982 Rott Creek Regional Statistics HEC-2 (EBRC) St. Joseph’s Creek Log-Pearson Type III HEC-2 (EBSJ) 1976 1976 Swift Meadows HEC-1 HEC-2 (EBSM) 1973 1976 22nd Street Log-Pearson Type III HEC-2 (EBTS) 1976 1976 Willoway Brook Log-Pearson Type III HEC-2 (EBWI) 1976 1976 Other Areas Zone A Varies (Local Studies, floods of Varies (Local Studies, floods of record, etc.) record, etc.)
The data currently being used for the FIS is severely out of date and is in need of significant updates due to large changes in land use, hydrology, channel condition, storage and other major changes within the watershed. DuPage County has revised the FIRMs to have existing flood profiles plotted on updated topography. In addition, DuPage County has developed a set of Regulatory Flood Maps which are map panels similar to FIRMs except that they reflect the latest effective flood zone boundaries as noted on the FIRMs and all effective Letters of Map Change issued by FEMA.
Floodplains are shown in Exhibit 13.
7.1.2. East Branch Mapping Updates DuPage County became a Cooperating Technical Partner with FEMA in order to update and modernize the County’s floodplain maps and identify other flood mapping tasks that need to be completed. DuPage County received grant funds from FEMA under the FY08 Map Maintenance initiative. As part of this program, DuPage County has updated hydrologic and hydraulic models for the three major watersheds (West Branch DuPage River, East Branch DuPage River, and Salt Creek) as well as a majority of its larger tributaries. The County utilizes HSPF for hydrology and FEQ for hydraulics in order to develop peak flood stages, peak flood flows, and flood volume tabulation for use in developing updated flood profiles. The flood profiles are computed through a peak-to-volume statistical method using a program called PVSTATS. These resulting flood elevations are plotted on County topography to create updated flood risk extents to be used on the latest FIRMs. Detailed discussion reports on the hydrology and hydraulic methods and results can be obtained through DuPage County Stormwater Management. 112
7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives
Model changes and updates generally include, but are not limited to the following:
• Updated land use representing 2003 data • Updated hydrology • Extended historical storm event series: 1948-2008 • Cross sections • Hydraulic structures (i.e. bridges, culverts, weirs, etc.) • Flood control facilities and other floodwater storage areas
These major updates for the watersheds include report documentation, flood profiles, and new flood maps which are on file with the County. The ultimate goal of these reports and maps is to have an updated DuPage County FIS and FIRM set that better represents existing flood risks throughout the County. The reports and maps were submitted to FEMA through the mapping process for the final approvals.
As of January 2015, the current status of the flood mapping is that the mapping and FIS are currently in FEMA’s Quality Review 3 (QR3) stage of the QA/QC process. The County is anticipating an open house on the latest mapping updates in April or May of 2015.
7.1.3. East Branch – River-Dumoulin Area A 2004 report, East Branch River-Dumoulin Flood Control Plan, analyzed major flooding issues centered on the Lisle area south of I-88 and north of Maple Avenue. As discussed in Section 6.2.3.1, this area is protected by a levee which was originally designed and constructed in the 1960’s for a 50-year level of protection. This plan divided the area into seven zones for analysis and discussion. HSPF and FEQ were utilized to perform hydrologic and hydraulic analyses of existing and alternative conditions. Various alternatives were analyzed to reduce flood damages in this area. The recommended plan was to perform levee maintenance and improve local drainage behind the levees by constructing four pump stations and constructing drainage swales and other infrastructure to convey water to the pump stations.
In 2008, DuPage County constructed four pump stations in this area. However, the levees are generally located on private property and DuPage County has been unable to secure property and/or easements to perform levee maintenance and improve local drainage towards the pump stations.
The East Branch DuPage River Levee Study Middleton Ave to Maple Ave was prepared for Lisle in 2012 in order to study, assess and provide recommendations for the system of non-accredited levees serving the East Branch DuPage River as well as St. Joseph Creek. It was determined that levee system was in dire need of maintenance due to significant settlement and erosion issues. It was also noted that the levee system was typically constructed of unsuitable materials which promote unstable embankment foundations. The recommendations generally comprised an improved maintenance plan in conjunction with strengthening the current levee system through a variety of options ranging from removing and replacing the levee, improving the levee core with bentonite or grout, capping the levee to design conditions, or constructing a steel sheet pile
113
7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives wall through the levee. Due to the significant cost and lack of property rights or easements, the recommendations have not been able to proceed to design and construction.
7.1.4. East Branch – Valley View Area Several studies and reports were prepared for an area along the mainstem of the East Branch DuPage River in unincorporated DuPage County called Valley View. Valley View is generally located along Illinois Route 53 south of Butterfield Road (Illinois Route 56) and north of Park Boulevard. This area is subject to frequent overbank flooding causing damages to homes and properties and extended road closures of IL 53. A 1992 Feasibility Study prepared by DuPage County and the USACE utilized updated hydrology and hydraulics to obtain peak stages and flows for the East Branch DuPage River for USACE to utilize for additional analyses. This study utilized the continuous simulation hydrologic model LANDS and the one-dimensional, unsteady flow hydraulic model FEQ. These updated models were initially started by DuPage County in 1984 in order to provide a tool for floodplain remapping, watershed planning and project analyses. This 1992 study included two versions of the hydraulic model to represent pre- and post-tollway (I-355) developments along the floodplain corridor. This model used actual precipitation and meteorological data from local rain gages covering the years 1949-1988. The model was calibrated to existing gages and hydraulic results for the storm events were statistically analyzed for USACE use.
The 1996 Valley View Flood Control Plan analyzed flooding along the East Branch DuPage River in Valley View and assessed damages associated with the residential properties along Illinois Route 53. This study facilitated the eventual voluntary buyout of various homes along this stretch of the floodplain corridor to reduce damages.
Another 2005 report focusing on the Valley View area was prepared by DuPage County for IDOT to prepare alternatives for Illinois Route 53 improvements in this area. This report utilized the latest version of the HSPF and FEQ model to analyze alternatives for raising the roadway profile above the base flood elevations to reduce the risk of extended road closures. The evaluation included maintaining floodplain storage and cross culvert drainage paths throughout the corridor. The recommendation was to shift and raise the roadway west while providing new local drainage on the west side and excavated compensatory floodplain storage on the east side.
7.1.5. Illinois Route 53 North DuPage County has prepared two reports from 1998 and 2003 for the East Branch DuPage River Route 53 North Flood Control Plan. The area around Illinois Route 53 north of Roosevelt Road (Illinois Route 38) has been subject to flood damages from overbank flooding in Glen Ellyn and unincorporated DuPage County. HSPF and FEQ modeling was conducted to analyze flood control alternatives to reduce the risk of flood damages. In addition, DuPage County worked with IDOT for the development of an appropriate bridge replacement for IL 53 which was eventually constructed. Recommendations generally included voluntary buyouts and flood proofing.
114
7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives
7.1.6. Other Local Studies Stakeholders within the watershed have conducted studies to evaluate flood impacts and potential projects on East Branch DuPage River tributaries, drainage ways, and storm sewer system. A summary of other studies completed is provided in Appendix B. This list is continuously updated based on updates from stakeholders regarding ongoing or planned studies. 7.2. Economic Analysis Many of the existing studies developing alternatives to address flood damage involve an economic analysis of the project. These analyses help evaluate the feasibility of flood control projects.
DuPage County typically performs an economic analysis by predicting flood damages on properties based on simulated flood stages from the FEQ hydraulic model results. A Depth- Damage curve was developed based on information compiled from FEMA, NRCS and USACE resources. This model, DEC-2, determines the expected structural, contents and associated damages to each structure for each storm event in DuPage County’s historical storms period of record (1949-2008). Damages for existing conditions are compared to the various alternatives to determine the benefits of the proposed action. In addition, the DEC-2 model also evaluates whether a structure is eligible for voluntary buyout under County guidelines for flood damages.
Other economic analysis concepts include evaluating the cost per acre of impervious areas or cost per homes impacted.
7.3. Recommended Alternatives Each existing study evaluating potential projects to reduce flood damages has a set of recommendations to move into design and construction phases. Recommendations typically involve the following:
• Conveyance improvements (larger channels, ditches, sewers, etc.) • Removing restrictive structures (bridges, culverts, dams, weirs, etc.) • Storage facilities (detention ponds, retention ponds, underground detention, compensatory storage, pumped flood control facilities, etc.) • Buyouts (purchasing and removing structure from flood prone area) • Flood proofing (protecting the structure from flooding through a variety of methods)
As projects are prioritized for implementation, complimentary benefits and long-term benefits must be identified. When several alternatives have similar benefits that meet the implentor’s objectives, the typical decision is to proceed with the most acceptable and lowest cost project. This is not only the fundamental approach of a design engineer, it is also the logical choice of municipal representatives seeking to best serve their constituency. But what if these alternatives were analyzed in a broader context - to identify benefits on a larger geographical plan or a longer planning horizon? When this is done, opportunities to build long-term
115
7. Hydrologic and Hydraulic Analyses: Studies, Economic Analysis and Preferred Alternatives resilience will not be missed. As an implementation plan is prepared, the East Branch DuPage River projects must be analyzed in this context.
A summary of recommended alternatives not yet implemented are listed in Section 8.2.2 in the identification of unmet needs throughout the watershed.
116
8. Watershed Needs and Issues 8.1. Watershed Resilience Principles & Goals This Plan’s overall goal, as stated in Section 3.1 is to enhance resilience, environmental quality, and community cohesion throughout the East Branch DuPage River watershed. Resilience, as described in the sidebar, is an approach to planning that improves a community’s capacity to prepare for and respond to shocks and stresses – whether floods, power outages, cold snaps or heat waves, or economic conditions – in a way that reduces adverse effects on people, economies, infrastructure, and the environment. In the Resilience is a term that emerged context of the East Branch watershed and this watershed from the field of ecology to describe Plan and the goals of Section 3.1, resilience refers most the capacity of a system to maintain directly to: or recover functionality in the event of a disruption or disturbance. Resilience: Building community’s collective ability to Resilience describes an area’s prevent, anticipate, and withstand flood events in the capacity to prepare for, withstand, and recover from exogenous and watershed with as little damage and disruption and unpredictable shocks with minimal possible. impact to people, infrastructure, environments, and economies. In Environmental Quality: Taking steps to protect and practice, resilience provides a enhance the water quality and physical condition of the framework for guiding planning, East Branch, and to allow the riparian system to function investment, and actions to reduce vulnerabilities. more naturally. - The Rockefeller Foundation: Community Cohesion: Creating a framework for Resilience Overview, National ongoing engagement in watershed issues, where Disaster Resilience Competition stakeholders have a measurable and beneficial effect on decision-making and investments in the East Branch watershed.
As described throughout this Plan, communities and people throughout the East Branch watershed face economic and physical risks from extreme weather events including heat waves, drought, winter storms, and high winds, and most often and significantly, from heavy downpours and flooding. Under most climate models and predictions for Northern Illinois and the Great Lakes region, these types of adverse events are projected to increase in frequency and severity. Communities can most effectively increase their resilience, and decrease their exposure and vulnerability to risk, by considering these adverse events in their planning and decision- making. And following a significant flood or storm, the recovery phase presents a valuable opportunity to consider how to rebuild in a way that reduces future risks.
This Section focuses on the specific actions that will enhance resilience, and to address four areas of significant vulnerability to “shocks,” damage, cost and disruption.
117
8. Watershed Needs and Issues
Table 8-1: Watershed Vulnerabilities and Resilience-Enhancing Actions
Vulnerabilities Resilience-Enhancing Actions
Infrastructure: The watershed’s physical and River-Dumoulin levee improvements environmental condition are threatened by aging infrastructure and inconsistent maintenance funding, Drainage improvements in flood-prone areas leaving essential systems such as levees, other flood control structures, sanitary and storm sewers, roads, Improvements to the County’s traffic lights to utility substations, and water systems vulnerable to ensure functioning during power outages disruption by storms and weather events
Housing: The watershed’s physical, social and Engage municipalities with flood-prone economic health is compromised by the ongoing neighborhoods on affordable housing, aging-in- needs for repairs, floodproofing, and buyouts of place, and neighborhood land use planning in the flood-damaged and flood-prone structures, which context of flood damage. represent both current unmet need and future economic and social risk particularly in the Most Complete buyouts and repairs in areas affected by Impacted-Most Distressed area. April 2013 flood.
Initiate voluntary buyouts of flood-prone structures Secure easements for maintenance of flood-related areas and key drainage corridors
Improve sanitary sewers to prevent overflows, backups and impacts on housing
Promote “landscape resilience” through rain barrels, native plantings, and other site-scale measures in key areas.
Environmental Degradation: The watershed’s Section 319 grant-funded water quality environmental health and ability to support improvement projects Beneficial Uses (aquatic life, contact recreation, fish consumption) are compromised by flood-related Tree canopy restoration pollution, ongoing non-point source pollution, hydrologic modification from watershed Non-point source education and outreach imperviousness and storm discharges, lack of tree canopy and stream bank buffers, and in-stream Strategic land conservation constrictions. Strategic stream restoration and invasive species removal
Dam/in-stream structures removal
Sanitary sewer separation in Lombard
118
8. Watershed Needs and Issues
Vulnerabilities Resilience-Enhancing Actions
Outdated/inadequate policy, finance and Review and assistance to update local codes, zoning regulatory tools: DuPage County and the and plans for water quality and resilience watershed’s municipalities lack sufficient authority gain access to key flood infrastructure; appropriate Strategy for securing easements or title to the River- financing for operation and maintenance; and Dumoulin Levee for maintenance and repairs incentives and standards that incentivize best practices in new development and redevelopment. Strategy for incorporating incentives and standards into new development
Creative strategy for ensuring consistent financing for essential operation and maintenance
Cooperative Bar Association/Title/ Insurance workgroup to assess needs and options for flood- prone areas, maintenance access
Social Cohesion: Resilience will be enhanced by Direct work with most affected neighborhoods to encouraging social cohesion in affected areas, and engage residents in defining options and outcomes throughout the watershed, enabling municipalities, residents and businesses better to prepare for and Field trips for officials and decision-makers to view respond to climate- and environment-related affected areas and infrastructure, particularly the stresses. River-Dumoulin levee
Watershed and river signage, including flood stage and high water levels, to greatly increase awareness of the river and watershed
Technical exchange with areas in the region farther along in the buyout and redesign process to gain insights and strategies
Direct engagement with foundations, social services providers, faith communities and organizations on flood preparedness, response and recovery options.
119
8. Watershed Needs and Issues
Vulnerabilities Resilience-Enhancing Actions
Leveraging: The watershed will benefit from a Leverage and explore alternative methods for cross-jurisdiction effort to identify potential county maintenance funding resources that can support resilience-enhancing actions. Begin to apply for Section 319 grant funds for water quality improvements
Utilize floodproofing funds
Use SRF and other sources for sanitary sewer and CSO improvements to help leverage water quality projects
Work with Illinois DOT on cooperative, resilience- enhancing projects such as traffic signals, alternatives to Route 53, wetland mitigation, and hydraulic projects.
Closely coordinate on open space and buffer acquisition with Park Districts, the Arboretum, and the Forest Preserve
8.2. Identification of Unmet Needs Unmet needs related to the prevention of, response to, and recovery from damaging flood events has been obtained through the stakeholder outreach process. Stakeholders have provided information that has been used to understand where there are needs related to housing, infrastructure, environmental degradation and economic revitalization. In addition, following the April 2013 flood event, DuPage County obtained funding through the U.S. Department of Housing and Urban Development (HUD) through their Community Development Block Grant – Disaster Recovery (CDBG-DR). The County was required to publish an action plan that documents unmet needs and how the funds can be used to address the recommended actions to assist with the disaster recovery efforts. Summaries of the CDBG-DR needs are described in the following sections in addition to other needs documented through the development of this Plan.
8.2.1. Housing Significant damage to housing occurred in the April 2013 flood event.
Owner-Occupied Unmet housing needs of owner-occupied residential property can be calculated using HUD’s methodology of using the number of housing units with unmet needs times the estimated cost to repair those units, less repair funds already provided by FEMA. To meet the statutory requirement of “most impacted,” homes are determined to have a high level of damage if they have damage of “major-low” or higher which is a real property FEMA inspected damage of $8,000 or flooding over four (4) feet (see Table 8-1 and 8-2). Using this methodology, the unmet housing need is calculated to be (may be duplicated households):
120
8. Watershed Needs and Issues
Table 8-1 DuPage County Residential Ownership Unmet Needs – Damage at least $8,000
Damage # of Units FEMA Loss-Pay Out Difference between Loss and Level Verified Loss Payout – Unmet Need Major-Low 308 $3,260,201 $2,578,938 $681,263 Major-High 152 $3,110,549 $1,837,064 $1,273,485 Severe 27 $1,040,798 $273,951 $766,847 TOTAL 487 $7,411,548 $4,689,953 $2,721,595
Table 8-2 DuPage County Residential Ownership Unmet Needs – Flooding Over Four Feet
Category Damage Level # of FEMA Loss-Pay Difference between Loss Units Verified Loss Out and Payout – Unmet Need 4-6 Feet Minor-Low 1 $2,394 $2,367 $27 st Minor-High 3 $21,103 $12,588 $8,515 1 Floor Major-Low 9 $111,515 $72,538 $38,977 Major-High 13 $249,829 $174,865 $74,964 Severe 1 40,847 0 $40,847 4-6 Minor-Low 17 $31,786 $25,845 $5,941 Basement Minor-High 59 $315,081 $223,646 $91,435 Major-Low 22 $221,857 $149,073 $72,784 Major-High 4 $73,805 $73,805 0 Severe 0 Over 6’ – Minor-Low 0 st Minor-High 2 $10,567 0 $10,567 1 Floor Major-Low 0 Major-High 1 $15,718 $15,718 0 Severe 0 TOTALS 132 $1,094,502 $1,750,445 $344,057 Based on previous experiences administering flood money, the initial Action Plan allocated $300,000 for rehabilitation and mold remediation for low/mod income households. When the activity actually commences, if it is determined that $300,000 is not a sufficient amount of funding for this activity, the unmet need will be addressed in a subsequent amendment. This unmet need for owner-occupied housing is only part of the story when it comes to housing needs in DuPage County. The initial Action Plan stated over 300 properties that meet the criteria for property buy-out that were affected by the April, 2013 flood event (subject to flooding depth of one foot above the low entry elevation for any one historic event, subject to a flooding depth of one-half foot for any two historic food events, or a FEMA repetitive loss structure). The initial Action Plan allocated $2,700,000 for property buy-out of 10-14 properties, leaving an unmet need for these structures of $71,500,000.
As stated in the initial Action Plan, there are many areas within DuPage County where property buy-out and demolition is the only solution to repetitive flooding of housing. Completion of infrastructure projects can also protect residential properties from future flooding. The projects proposed in this Amendment Number 1 would result in the following housing impact:
121
8. Watershed Needs and Issues
• Buy-out of approximately 44 properties (Approximately 14 properties with $3,297,000 for strategic buy-outs and approximately 30 properties using $1,250,000 in leveraging with HMGP buy-out match) • As reflected in the updated infrastructure needs below, infrastructure projects will benefit at least 257 homes by lessening the impact of future flood events.
Substantial Amendment #1 is currently being reviewed to be incorporated into this document.
In addition to the properties submitted either in the Hazard Mitigation Grant Program (HMGP) or CDBG-DR funding, the Village of Lisle still has 25 properties that were damaged by the April 2013 flood. Under FEMA’s National Flood Insurance Program (NFIP), a majority of the homes meet the 50-percent damage threshold and therefore cannot be repaired. The other homes have incurred significant damage and still have unmet repair needs. Acquisition of homes is needed in some areas to prevent future damage. More than 223 homes identified by DuPage County meet flood-prone criteria and are eligible for purchase under the County’s buyout program. FEMA also reported an additional 87 repetitive loss structures in DuPage County that meet the substantive damage threshold. One particular flood-prone area in the Village of Lisle has initiated a home buyout, which is described in Section 8.3. Thirty-six homes are identified for acquisition in this area. The Village of Lisle projects the cost to acquire these thirty-six homes to be approximately $7,500,000, or $208,333 per house, including demolition costs. It should be noted that the average home value in this acquisition area is $174,445, well below the reported home value within the watershed of $280,745 reported in the U.S. Census. The magnitude of potential home acquisition costs, in the absence of flood prevention measures, would be the number of flood-prone or repetitive loss homes (310) multiplied by the home value ($280,745) plus demolition costs ($40,000), which yields a total eventual cost of $99,430,950.
The acquisition of flood-prone homes will clearly be an incremental process. The process is voluntary on the part of the homeowner and the decision to accept a buyout offer requires time to consider. Within the East Branch Watershed, it is expected that a buyout program will attract participation in the range of 50% of the 310 eligible homes over a ten year period, resulting in an estimated total of 155 homes acquired in that period. Based on these assumptions, the estimated budget for home acquisition is $36,885,675.
8.2.2. Infrastructure Additional discussion is currently being prepared.
CDBG-DR Updated infrastructure needs: The initial Action Plan identified unmet need that was unable to be addressed with the first allocation of funds that will now be addressed with this second allocation of funds. Additional infrastructure needs have also been identified, see Table 8-3.
122
8. Watershed Needs and Issues
Table 8-3 Infrastructure Needs
Westmont Liberty Park Detention pond 175 homes directly Improvement Project – expansion, storm sewer impacted by this project massive residential rehabilitation - flooding during the improvements of April, 2013 flood. Many $1,000,000. This need properties in Liberty was identified after the Park are on the property initial Action Plan. The buy-out waiting list. buy- outs proposed under the initial Action Plan and in this Amendment 1 will enable this infrastructure project to be completed. Glen Ellyn Flooding at Lake Ellyn Improvements of outlet control structure $245,000 were identified as an unmet need in the initial Action Plan. The project, however, is contingent upon completion of planning by the Village of Glen Ellyn and final eligibility review. Glen Ellyn Flooding at Perry’s New inlet structure and Pond (connection revision to storm sewer between Joseph Sam pipe configuration - Perry Preserve and $275,000 was identified Perry’s Pond) as an unmet need in the initial Action Plan. The project, however, is contingent upon completion of planning by the Village of Glen Ellyn and final eligibility review.
Other Infrastructure Needs
Increased roadway capacity for diversions and detours during flood events is an unmet need of this watershed due to major routes being closed or severely limited in their capacity to maintain vehicular traffic patterns efficiently. Example is improving College Road in Lisle to provide adequate traffic capacity for Route 53 closures around Ogden Avenue during flood events. This type of improvement will provide opportunities for increased use of arterial streets instead of
123
8. Watershed Needs and Issues
local streets not designed to handle the traffic and vehicular weight of diverted traffic from Route 53.
As noted in Section 7.1.6, various municipalities and other stakeholder entities have conducted studies on flood risk and potential projects throughout the watershed. As of the date of initial publication of this Plan, Table 8-X provides a summary of flood risk reduction projects identified by the stakeholders. Additional projects including those listed in this table can be found in Appendix D.
Table 8-X: Flood Risk Reduction Projects Identified by Stakeholders
Problem ID Cost Project Location Description Addressed (Year of Cost Est.) Main St and Glenrise culvert East Branch replacement Tributary No. 2 Uninc. EBE2-01 $752,000 Compensatory Storage Watershed Plan DuPage EBE2-02 (1996) Buyout Alternative 3 Floodproofing Levee Maintenance 4 – Stormwater Pump Stations EBEB-01 and associated stormwater EBEB-02 River-Dumoulin improvements EBEB-03 $11,578,000 Flood Control Plan Lisle Buyouts EBEB-04 (2004) Alternative A2 Floodproofing EBEB-05 (Note: 4 pump stations EBSJ-01 constructed in 2008) EBEB-01 $7,000,000 Levee Maintenance / East Branch EBEB-02 to $20,000,000 Replacement DuPage River EBEB-03 (range of options does Lisle Streambank Stabilization Levee Study EBEB-04 not include Easements Operations Plan EBEB-05 or Property Easements EBSJ-01 Acquisitions) Relocate and raise IL 53 above Illinois Route 53 $12,000,000 Uninc. flood elevations. IL 56 to Park EBEB-08 Acquisition: DuPage Improved local drainage Boulevard $9,000,000 Compensatory Storage Illinois Route 53 Glen Ellyn North Flood Buyouts $598,000 Uninc. EBEB-10 Control Plan Floodproofing (2003) DuPage Alternative 1 Morton Sump pumps (completed) Arboretum Uninc. Floodproofing (completed) EBEB-11 TBD Building DuPage Groundwater flow diversion Protection $245,000 Lake Ellyn Outlet Outlet control structure Glen Ellyn EBEB-13 (funding through Control Structure modification CDBG-DR Funds) $275,000 Perry’s Pond Storm sewer improvements and Glen Ellyn EBEB-14 (funding through Improvements modifications CDBG-DR Funds)
124
8. Watershed Needs and Issues
Problem ID Cost Project Location Description Addressed (Year of Cost Est.) Storage facility $244,000 Downers Sewer improvements (2014) Black Oak Drive EBLA-01 Grove Berms Does not include Easements easements $393,800 Downers Dr / Sewer improvements To $664,000 Virginia St / Seeley Downers Online flood storage EBLA-02 (2014) Ave / Grove Easements/Property Does not include 40th St easements $429,000 Downers Sewer improvements (2014) Elm and Earlston EBLA-03 Grove Easements Does not include easements Storage facility $565,000 Hobson Triangle Downers Sewer improvements EBPR-01 (2014) Area Grove Acquisition Storage facility $875,000 Triangle Park Woodridge Streambank stabilization EBPR-02 (2014) Sewer improvements St. Joseph’s Creek Downers Culvert replacement $3,412,000 North Flood Plain EBSJ-02 Grove Compensatory storage facility (2014) Project No. 1 Overflow route $2,009,000 St. Joseph’s Creek Downers Berms (2014) South Flood Plain Grove Culvert improvements EBSJ-04 Does not include Project No. 3 Westmont Compensatory Storage easements Easements / Property St. Joseph’s Creek Overflow route $1,470,000 Downers South Flood Plain Storage facility EBSJ-05 (2014) Grove Project No. 4 Property Storage facility $1,233,000 Pershing between Downers Sewer improvements EBSJ-06 (2014) Ogden and Grant Grove Property $1,580,000 Washington south Storage facility Downers (2014) of Ogden/Highland Sewer improvements EBSJ-08 Grove Does not include Court Easements/Property easements $252,000 Drendel Road Storage facility Downers (2014) South of Sewer improvements EBSJ-09 Grove Does not include Indianapolis Easements/Property easements Property coordination $903,000 Chase Avenue Berms Downers (2014) between Haddow Storage Facility EBSJ-10 Grove Does not include and Warren Sewer Improvements easements Easements/Property Walbank north of Downers $13,000 Restrictors removal EBSJ-11 Warren Grove (2014) $784,000 South of Prairie Sewer improvements Downers (2014) between Forest Storage Facility EBSJ-12 Grove Does not include and Price Easements/Property easements 125
8. Watershed Needs and Issues
Problem ID Cost Project Location Description Addressed (Year of Cost Est.) Debolt / Linden / Downers Roadway improvements $241,000 EBSJ-13 Gierz Grove Sewer improvements (2014) $944,000 Hitchcock between Downers Sewer improvements (2014) Cornell and EBSJ-14 Grove Easements Does not include Glenview easements $694,000 Sewer improvements Middaugh and Downers (2014) Storage Facility EBSJ-15 Jefferson Grove Does not include Property easements West side of $422,000 Berm Lyman between Downers (2014) Sewer improvements EBSJ-16 Kenyon and Grove Does not include Easements Blanchard easements $66,000 Francisco Street at Downers Sewer improvements EBSJ-17 To $178,000 Burlington Grove (2014) Storage facility $1,000,000 Liberty Park Westmont Sewer improvements EBSJ-18 (funding through Improvement Property CDBG-DR Funds) Backflow preventers Richmond-Grant $35,000 Westmont Sewer improvements EBSJ-19 Project (2011) Monitoring wells Storage Facility Roslyn-Burlington $350,000 Westmont Sewer improvement EBSJ-20 Project (2011) Backflow preventers Pershing from President to Wheaton TBD. Study in review phase EBWI-02 TBD Prospect Brentwood and Wheaton TBD. Study in review phase EBWI-03 TBD Briarcliffe
The County and some municipalities have conducted a variety of studies to assess existing flood risk and develop potential solutions. However, other municipalities and areas of the watershed have either outdated local studies or are completely lacking in studies focusing on more localized issues associated with smaller stormwater systems. Examples include several smaller tributaries to the East Branch DuPage River that have outdated and minimal data available relative to floodplain mapping. Many of these smaller tributaries are contained within a single community and typically require the community to develop updated analyses and assessments of flood risk.
8.2.3. Impacts to Environmental Health Additional discussion is currently being prepared.
8.2.4. Economic Impacts Additional discussion is currently being prepared. 126
8. Watershed Needs and Issues
8.3. Most Impacted / Most Distressed Area During the April 2013 storm event, levee overtopping and failure coupled with poor internal drainage systems conveying runoff to the pumps stations caused numerous homes and buildings to be flooded. The Village of Lisle noted that approximately 180 structures in the floodplain were damaged with 35 homes declared substantially damaged (damage estimated at or above 50% of the value of the structure). The Village and DuPage County have been actively pursuing funding to acquire and floodproof homes in this area through Hazard Mitigation Grant Programs and CDBG-DR funds. However, there are still unmet needs related to property acquisitions, levee maintenance access, levee improvements and local drainage improvements. Many of these homes cannot be occupied due to their substantial damage threshold and this causing severe stress on residents of this area who cannot repair or move back into their homes combined with the lack of available and similar housing nearby.
There is a critical and immediate need for assistance in this area. Currently Lisle and DuPage County have funding available to acquire approximately 20 properties in this area. There is significant concern with the restrictions placed on the funding types. Funding obtained through the Hazard Mitigation Grant Program (HMGP) to purchase properties that include the levee would severely restrict any future maintenance of the levee. Deed restrictions are placed on the purchased property to basically limit the future uses of the property which would exclude repairing, replacing or providing long-term maintenance of the levee system. This provides a dire situation for future flooding in this area if the levee cannot be repaired due to removal of damaged structures through this type of funding. 8.4. Additional Flood Impacted and Distressed Areas As discussed in Section 6.2.4, East Branch DuPage River stakeholders identified a variety of flooding areas throughout the watershed. Many of these problems were identified as a direct result of the April 2013 flood event while other problems have been known issues for the community for an extended period of time. Detailed descriptions of these problems and their associated unmet needs are provided in Section 7 or Appendix B.
Although many of these problems are considered to be local issues on a block or neighborhood scale, these issues can have a regional and national impact to the entire watershed and downstream communities along the East Branch DuPage River to the DuPage River to the Illinois River and ultimately to the Gulf of Mexico via the Mississippi River.
A significant number of these problem areas have been studied and analyzed to develop recommended solutions to provide a reduction in the risk of flooding for the community.
Significant historical flooding within the East Branch DuPage River has occurred at several locations that have been well documented by DuPage County and municipalities. Major flooding in the watershed has generally been a result of overbank flooding, high groundwater levels during flood events, local drainage backups behind levees, high flood waters overtopping existing levees, levee failure, flood storage overtopping, sanitary backups, depressional areas and inadequate stormwater conveyance systems.
127
8. Watershed Needs and Issues
For many of the other areas impacted by flooding, there are a variety of recommendations for reducing the risk and increasing the resiliency of these distressed areas. Implementation of the recommendations will require wide ranging involvement from residents and business owners to municipalities to County and State and Federal officials.
Recommendations are currently being prepared.
8.5. Critical Areas of Environmental Degradation A discussion is pending.
128
9. Recommended Action Plan 9.1. Watershedwide Programmatic Plans Establishing recommended actions throughout the watershed can ultimately provide benefits to the watershed residents, businesses and stakeholders. Actions can have far ranging impacts to prevention, response and recovery to flood events. A watershedwide programmatic plan requires diligent coordination among the governmental entities and stakeholders to gain regional acceptance and buy-in to the recommendations. Recommendations are discussed in the following sections.
9.1.1. Infrastructure 9.1.1.1 Early Flood Warning System In DuPage County, the East Branch DuPage River does not have similar flood warning systems similar to those along Salt Creek and the West Branch DuPage River. Early flood warning systems can provide people with the opportunity to prepare and react to a damaging flood disaster in a timely fashion. The East Branch DuPage River will typically reach its peak flood stage around this area within a day or two following a severe rain event. While that is enough time for residents and businesses to understand and adapt to the risk, there is currently no coordinated warning system to provide this outreach and notification. A flood warning system will provide the ability for the community to be resilient to future flood events due to its increased ability to react and recover.
It is recommended that DuPage County install a flood monitoring and warning system within the East Branch DuPage River Watershed which includes, but is not limited to the following:
• Develop a flood warning task force to coordinate these efforts • Install additional rain gages throughout the watershed • Install additional stream gages (flow and stage) throughout the watershed and its tributaries • Investigate additional coordination opportunities with other neighboring counties (Will, Cook, Lake, McHenry, Kane) and agencies such as USGS, ISWS, USACE, FEMA, IEMA • Investigate funding opportunities for the installation and operations of new monitoring equipment • Establish, refine and improve upon a flood warning protocol system with OEM to coordinate outreach before, during and after flood events • Set up a variable method notification system to provide warnings. This can include Reverse 911-style activities, emails, text messages, website and social media updates. However, care must be taken to provide opportunities for notifications for areas of low to moderate income, areas with elderly populations and areas with non-English speaking populations. Examples of other warning activities can include tornado siren style warnings, partnering with local businesses to access their variable display messaging board in order to provide warnings, and door-to-door efforts in these areas.
129
9. Recommended Action Plan
• Develop a robust flood forecasting effort that can provide graphical and textual understanding of flood risks associated with impending storm events • Establish relationship with College of DuPage to coordinate their flood forecasting efforts with the County’s
9.1.1.2 Stormwater Infrastructure Stormwater infrastructure is critical for handling stormwater runoff during storm events. Collection, conveyance and storage facilities can redirect runoff volume to minimize the risk of flood damages to property and other infrastructure systems. As noted in Section 8.2.2, there are significant unmet needs related to infrastructure improvements to alleviate flooding and associated damages.
The following actions are recommended related to stormwater infrastructure
• Develop a regional/watershed planning committee to look for opportunities to coordinate local stormwater projects • Incorporate multiple benefits and amenities for proposed stormwater projects. Examples can include creating new park or open space in a compensatory storage facility, incorporating recreational trail systems in facilities and along river/pipe corridors, providing naturalized planting zones, and other amenities. • Develop a prioritization program to consolidate proposed projects and address those that have the greatest benefits to cost ratios. Benefit to cost ratio should expand beyond just focusing on flood damages to show how a project can be resilient and beneficial to the community. • Investigate additional funding or teaming opportunities.
9.1.1.3 Transportation Providing a resilient transportation system that can retain its effective capacity during flood events or other disasters can improve the quality of life of residents and businesses while providing greater ability for emergency and public works response before, during and after an event.
It is recommended that the following transportation related improvements and actions be made throughout the watershed:
• DuPage DOT should continue its conversion of traffic lights from incandescent bulbs to energy efficient LED modules. In conjunction with this conversion, DuPage DOT should install uninterruptable power supply (UPS) units in the traffic signal cabinets. The UPS units combined with the LED modules will allow the traffic signal to remain in full operation (rather than blinking red stop light only) in the event of a power outage. • Municipalities should plan for conversion of traffic lights to LED modules with UPS units with a priority on key transportation routes related to residential, business and emergency services traffic patterns.
130
9. Recommended Action Plan
• DuPage County should work closely with IDOT for assistance with necessary land acquisitions and transfers to expedite the ultimate construction of the improved Illinois Route 53 between Butterfield Road (Route 56) and Park Boulevard. This project will significantly reduce the risk of extended Route 53 closures during flood events. • DuPage County, Lisle and IDOT should establish a working group to evaluate options to reduce the risk of Illinois Route 53 flooding near Ogden Avenue. This work group could be directly related to the Levee Task Force discussed in Section 9.2. • Lisle should establish a working group to evaluate the feasibility of expanding the capacity of an alternate north-south roadway corridor to provide a more resilient transportation system during flood events which causes Illinois Route 53 near Ogden Avenue to close. Widening College Road and Yackley Avenue could provide additional capacity for vehicles during disaster events. • DuPage DOT, DuPage Stormwater, IDOT, Townships, and Municipalities should develop a database of hydraulic structures (bridges, culverts, etc.) that are subject to overtopping or other flooding during storm events. It is recommended that these entities coordinate improvements to these structures on a regional scale to coincide with other flood reduction projects and actions in order to reduce the risk of overtopping and flooding of the roadway.
9.1.1.4 Green Infrastructure Programs The East Branch DuPage River watershed is home to one of the first regionally well-known large scale green infrastructure installations. A large permeable pavement parking lot and bioswales were installed at the Morton Arboretum over 15 years ago. These green infrastructure systems, located adjacent to the floodplain of the East Brach DuPage River, serve to reduce and cleanse runoff prior to its discharge to the river. This highly visible and heavily trafficked site has served to encourage other would-be green infrastructure implementers ever since. Support for green infrastructure in DuPage County continues to grow.
Within the last several years, DuPage County has significantly enhanced the requirements for new development and redevelopment to implement best management practices that provide volume control and pollutant control. In 2014, DuPage County cohosted a Green Infrastructure Symposium to help local contractors make business decisions regarding pursuing green infrastructure. Green infrastructure implementation will continue to grow as various programs continue to reach effective target audiences. This includes making owners and governing bodies aware of opportunities on existing sites (public or private). Providing technical assistance and timely advice can encourage owners of large properties to consider implementing naturalized stormwater management features into their site revitalization plans. Future efforts should also include continued outreach and support to municipalities to implement green infrastructure improvements as part of municipal projects. Finally, DuPage County will continue to reach out to the contracting community to continue to build capacity and knowledge of how to implement effective systems.
131
9. Recommended Action Plan
9.1.2. Housing 9.1.2.1 Property Acquisition, Voluntary Buyouts and Easements In many flood prone areas, there is no permanent infrastructure solution to flooding and an acquisition (buy-out) is the only solution to provide long term recovery. There are several methods of determining property acquisition related to a flood event in DuPage County. Voluntary buyouts in DuPage County can occur when:
• Structures are not protected by capital improvement projects in approved watershed plans • Structures are subject to flooding depths of one foot above the low entry elevation for any one historic event • Structures are subject to flooding depth of one-half foot for any two historic events • FEMA repetitive loss structure • Other data subject to grant application rules
There are also a variety of sources that could provide funding or funding matches to assist with acquisitions including FEMA grants, Hazard Mitigation Grant Programs, Disaster Recovery Grant programs, HUD programs, and others. Programs might have different rules and regulations regarding the acquisition and subsequent use of the property.
HMGP funding limits the use of the property following the buy-out and demolition of the structure. Any property purchased with these funds must be dedicated and maintained in perpetuity as open space for the conservation of natural floodplain functions. Uses include park, wetlands, open space, buffer zones, and other similar unimproved open space areas. While these restrictions are important for providing open space areas while not introducing new structures that can be damaged, it can severely limit the ability of an entity to maintain, repair and improve infrastructure systems originally on this property. This is very applicable to the levee system in Lisle adjacent to the East Branch DuPage River and St. Josephs Creek where the levee is mostly situated on private property.
It is recommended that DuPage County and other stakeholders do the following regarding property acquisition:
• Engage municipalities and unincorporated areas with flood-prone neighborhoods with respect to affordable housing, aging-in-place, and neighborhood land use planning in the context of flooding and flood damages • Complete repairs, remediation, rehabilitation and acquisitions in areas affected by the April 2013 flood. • Identify and recommended property acquisitions to remove properties from the floodplain in accordance with the voluntary buyout program(s) and other regulatory requirements. • Identify and recommend property acquisition to transfer publicly-related infrastructure (i.e. levees) to the appropriate and designated owner for future repair, maintenance and improvements.
132
9. Recommended Action Plan
• Identify property / easement needs for future stormwater infrastructure projects to reduce the risk of flood damages. • Identify appropriate funding sources that do not limit the future repair, maintenance and improvements to the infrastructure systems. • Provide active coordination and education of property owners and stakeholders as to the needs to provide resilience to future flood events
9.1.2.2 Floodproofing Floodproofing can provide property owners with the ability to reduce the risk of damages caused by flooding through a variety of methods. FEMA has extensive documentation on floodproofing methods and measures that can provide property owners with guidance on how to plan, design, and implement these features. In many areas, minor flooding adjacent to structures can cause significant damages. However, implementing floodproofing measures can prevent this flooding from impacting the structure and its contents or reduce the damages to the structure and its contents. Actual methods would have to be coordinated with current regulations to determine if the method is acceptable under the National Flood Insurance Program.
It is recommended that DuPage County and municipalities do the following regarding floodproofing:
• Establish and improve available resources (online, print, seminars, etc.) for home and business owners • Investigate grant and other funding opportunities to provide assistance for floodproofing • Investigate development of a municipal or county financial match for floodproofing
9.1.2.3 Sanitary Sewers Sanitary sewer systems are critical components of the area’s infrastructure system. When these systems are inadequate or fail, damages to structures as well as the degradation of the health and well-being of residents will occur. Sanitary sewer systems can be subject to infiltration and interception of stormwater due to system leaks, illicit connections and other issues. In addition sanitary sewer systems may become surcharged during storm events and cause sanitary sewage to backup into people’s homes and businesses causing extensive damage and the potential for long term issues related to health including mold and bacteria growth following a sewage backup.
In many areas in the watershed, there are residential neighborhoods that currently utilize septic systems in their yards for treatment of sanitary discharge. Many of these areas are beyond the limits of the existing municipal or County sanitary sewer systems. Flooding issues impact these systems by filling them with stormwater or high groundwater saturations which can potentially cause backups and the lack of ability to utilize the sewage system.
Additional discussion on combined sewer overflows is being prepared.
It is recommended that an improved sanitary program be implemented by the County and municipalities including: 133
9. Recommended Action Plan
• Improve outreach and marketing efforts for the existing sanitary sewer programs to help residents install overhead sanitary sewer systems or approved flood control methods to prevent and reduce the risk of future sanitary sewage backups. • If a municipality does not have an existing sanitary sewer program, investigate the potential need to address sewage backups and to potentially provide assistance. • Conduct smoke testing to identify potential infiltration and interception (I/I) sources in the sanitary system. • Conduct sanitary sewer televising to identify sections of sewers that need repair, rehabilitation or replacement and prioritize these sections in the near-term budget allocations • Establish a program to educate and assist homeowners for disconnection of sump pump systems from sanitary sewer systems.
9.1.2.4 Landscape Resilience Examples of potential green infrastructure programs show how ideas to implement green infrastructure can be pursued and implemented along multiple fronts. As the critical mass of green infrastructure continues to build, more and more projects will be implemented, and the landscape of green infrastructure will be figuratively and literally is transformed from a few demonstration projects to a distributed network of functioning stormwater management systems. While this will take time, it will enhance the resilience of the landscape. There will also be ancillary benefits to an ever increasing, but distributed stormwater management system.
Much attention has been focused on areas that have the worst damages and highest unmet needs. These are in fact, the areas that are most impacted by flooding. But it is shortsighted to ignore widespread commonality of individual homes or small groups of properties that experience flood damage. Most often, these are homes that have been unfortunately constructed in a depressional area with an obstructed overland flowpath, now only drained by sewer. One only has to look at a community’s map of the reported flood damages and stormwater problems to see that while there will be hotspots of problems, the remainder of the landscape is frequently interrupted by smaller scale complaints. The pursuit of a distributed stormwater management system, through various programs, will continue to pay off, not only in the hotspots, but for the rest of the community as well.
9.1.3. Environmental Health The East Branch DuPage River should have the ability to support its beneficial uses including aquatic life, contact recreation and fish consumption. The health of the watershed can be compromised by flood related pollution, non-point source pollution, hydrologic modification, lack of tree canopy, lack of streambank buffers and other instream constrictions and issues. Improved environmental health of the watershed and river can improve the ability of the residents and stakeholders to access and utilize the East Branch DuPage River as a recreational asset while reducing the risk of hazards resulting from polluted waters.
In order to improve the environmental health of the East Branch DuPage River, the following actions are recommended:
134
9. Recommended Action Plan
• Continue and expand Section 319 grant-funded water quality improvement projects. • Improve the restoration of the tree canopy in the river corridors. • Improve and expand non-point source pollution education and outreach • Conduct and combine strategic land conservation efforts throughout the watershed with the variety of stakeholders who are conducting their own analyses and efforts. • Perform strategic stream restoration projects and invasive species removal • Evaluate and implement dam or other in-stream structures removal
Additional information regarding non-point source actions can be found in Section 9.3.
9.1.4. Policy, Finance and Regulatory Tools DuPage County and municipalities lack sufficient authority to gain access to certain key flood infrastructure components. In addition, the County, Townships, and municipalities need to have a greater understanding of current and future operation and maintenance needs in order to appropriately finance these efforts.
9.1.4.1 Local Codes and Plans To promote a greater and broader resilience throughout the watershed, it is imperative to coordinate, improve and update local codes, zoning and plans to encourage the development of resilient-based actions.
• Develop a regional or County work group to facilitate the development of improved and coordinated code, zoning and planning guidelines. • Improve local codes encouraging green infrastructure and other resilient and forward looking improvements to properties. • Incorporate planners, engineers, architects, policy makers, etc. into creating long term sustainable community plans.
9.1.4.2 Easement Requirements Easements can provide the opportunity for property access to facilitate maintenance, repairs, or improvements. It is imperative that there is a responsible entity for the maintenance, repair and improvement of infrastructure designed to provide protection during disasters (such as a levee during a flood event). Equally important is making sure that this responsible entity has access to the infrastructure facility/component before, during and after a disaster.
In addition, many detention facilities constructed under the DCCSFPO for property developments are located on private property. These facilities provide a degree of risk reduction during flood events by storing water and reducing the peak discharge of stormwater runoff from the site which can impact downstream areas. Many of these facilities are in varying states of disrepair including siltation and sedimentation, eroding slopes, broken or failing outlet control structure or unmaintained emergency overflow routes. Since these facilities were constructed to mitigate downstream risk of increased peak flows, it is imperative that they should be in a state of good condition similar to what was originally permitted.
The following actions are recommended regarding easements:
135
9. Recommended Action Plan
• Identify public or critical infrastructure situated on private property • Document existing easements, records, titles or other information pertaining to each infrastructure component on private property • Create a working group to develop a strategy for securing necessary easements • Establish inventory of flood control facilities (i.e. detention ponds, retention ponds, underground storage vaults, compensatory storage, etc.) throughout the watershed and create a database to track ownership, facility characteristics, and the facility’s status. • Create an inspection and enforcement team to track flood control facilities and develop a maintenance / repair enforcement system
9.1.4.3 Incentive Programs Additional discussion is currently being prepared.
9.1.4.4 Work Groups Create a cooperative work group comprised of Bar Association, Tax, Title, and Insurance entities to address existing inadequacies and create better opportunities for resilient communities.
9.1.4.5 Funding Additional discussion is currently being prepared.
9.1.5. Social Cohesion It is important to have the social infrastructure to support disaster preparedness, response and recovery. By improving the stakeholder understanding of their community, there can be an improved ability to coordinate efforts to build future resiliency.
9.1.5.1 Education and Outreach It is also important to promote a greater understanding of a watershed (specifically the East Branch DuPage River) and how the actions and activities of communities and stakeholders can have a wide ranging impact on the rest of the watershed. Understanding where water in the riverine system is coming from and where it is going can provide a critical link between the communities and stakeholders.
It is recommended that DuPage County and other stakeholders develop an educational outreach program that includes:
• Comprehensive understanding stormwater infrastructure systems including site field trips for stakeholders, public officials and other decision makers to show drainage and stormwater infrastructure • Work with IDNR and USACE to develop a Flood Fighting School program for the watershed including how to prepare and react to floods • Provide and promote sand bag and bladder distribution systems at the municipal and countywide level to assist residents with preparation and response • Develop a watershed signage program for denoting watershed (and subwatershed) boundaries, record flood signs, evacuation and emergency routes, etc.
136
9. Recommended Action Plan
• Develop and provide training sessions for an Emergency Action Plan for flood prone areas • Provide training and information on early flood warning systems and how to be informed and aware before, during and after disaster events
9.1.5.2 Emergency Services The current Public Works Mutual Aid (PWMA) network provides the ability with municipalities to coordinate and assist each other when their resources are fully tied up during a disaster or emergency situation. This mutual coordination provides an excellent resilience measure for the region to prepare, react and recover from a disaster. In addition, the PWMA can utilize the Illinois Public Works Mutual Aid Network (IPWMAN) in the event that the region’s resources are fully occupied. It is recommended that DuPage County continue to coordinate these efforts while also investigating opportunities to expand the education and outreach of these services to continue to provide beneficial services to the area.
9.1.5.3 Community Services Engagement with other community members such as foundations, social services providers, faith communities and other organizations can help the entire community become more proactive with respect to flood or disaster preparedness, reaction and recovery. Many of these community service institutions assist by providing shelter, food, medical treatment, counseling and much more.
It is recommended that governmental entities increase the outreach and coordination efforts with these community service providers to help foster a broader sense of resiliency related to disasters.
9.1.6. Leveraging Additional discussion is currently being prepared.
9.1.6.1 County Maintenance Program Additional discussion is currently being prepared.
9.1.6.2 Water Quality Grant Program Continue and expand current water quality grant program.
Additional discussion is currently being prepared.
9.1.6.3 Floodproofing Cost share? Grants?
9.1.6.4 Sanitary Sewer Isn’t this just a repeat of 9.1.2.3?
137
9. Recommended Action Plan
9.1.6.5 Planning Studies Discussion on trying to assist with unstudied or out of date studies for FEMA FIRM areas. Provide planning level process guidelines for communities. Work with other stakeholders to develop regional plans (i.e. USACE DuPage River)
9.1.6.6 Transportation IDOT IL 53 at Valley View (not sure how this can be leveraged)
Recommend municipalities to apply for MFT funds to assist with roadway, bridge and culvert projects which can also address flood issues.
9.1.6.7 Open Space Opportunities Work with Morton Arboretum, Forest Preserve, Chicago Wilderness, etc. to coordinate open space restoration and plans. 9.2. Site Specific Flood Risk Reduction Plans Blah blah about site specific flood control plans and projects. Collected info. See Appendix D for a list of recommended projects
9.2.1. Most Impacted / Most Distressed – River Dumoulin Area Blah
9.2.1.1 Levee Task Force It is recommended that DuPage County in conjunction with the Village of Lisle create a collaborative group of stakeholders for the River-Dumoulin area to investigate, recommend and pursue the necessary easements and acquisition of property to transfer ownership of the physical limits of the levee corridor to DuPage County Stormwater for permanent ownership to facilitate future maintenance and improvements to the levee and the interior drainage system. Currently the levee system is mostly on privately held land with little to no access available through property or easements for maintenance.
Any future resiliency to flood events in this area is directly linked to the ability to repair, improve and maintain the current levee system. As it stands, the levee system cannot be fully accessed to provide these actions.
A key function of this group is also to educate the residents and business protected by the levee on how the levee functions, why it is important to continuously maintain and improve it, and how the levee system and associated river corridor could provide multiple benefits for the stakeholders. Additional benefits of the levee system could include the following to provide multiple benefits and resiliency of the levee system:
• Access road on top of levee for emergency, evacuation and maintenance • Multi-Use Trail and Recreational Corridor • Open space areas • Community gardens and parks • Educational and informational signage 138
9. Recommended Action Plan
• Land swaps • Improved pedestrian and recreational circulation • Improved local drainage systems behind levee and on acquired properties to convey stormwater runoff to the recently constructed pump stations
It is recommended that the Levee Task Force complete the following tasks:
• Stakeholder Identification and Outreach for the River-Dumoulin Levee System • Conduct outreach meetings to educate the public and stakeholders about the importance of the levee system and the need to have a dedicated operations and maintenance plan • Identify repair and replacement needs • Identify property and easement needs • Identify multiple benefits associated with the levee system and coordinate with stakeholders • Recommend levee improvements and associated property and easement needs • Identify funding mechanisms • Provide implementation schedule
9.2.1.2 Property Acquistions and Easements In this area, approximately 180 structures were damaged during the April 2013 flood event with 35 of them declared substantially damaged.
In the River-Dumoulin area of Lisle, funding has been allocated for acquisition of approximately 20 with additional potential funding for another five to ten homes. However, there is still an unmet need of at least five homes that meet buy out criteria. Some of this funding is associated with the HMGP which limits the use of the property following the buy-out and demolition of the structure. Any property purchased with these funds must be dedicated and maintained in perpetuity as open space for the conservation of natural floodplain functions. Uses include park, wetlands, open space, buffer zones, and other similar unimproved open space areas. While these restrictions are important for providing open space areas while not introducing new structures that can be damaged, it severely limits the ability of an entity to maintain, repair and improve a levee that is located on the property. For the River-Dumoulin area, the levee could not be repaired to provide the protection it was originally designed for if the private properties with the levee on them were purchased using these funds.
Due to these limitations, it is critical that additional funding sources are identified and secured that provide the ability for the new owner of levee properties to be able to repair and maintain the existing levee system.
It is also important to be able to acquire the appropriate property and access rights for the levee system in order to meet the goals of the Levee Task Force described in Section 9.2.1.1.
It is recommended that DuPage County, Lisle and other stakeholders do the following regarding property acquisition:
139
9. Recommended Action Plan
• Identify and recommended property acquisitions to remove properties from the floodplain in accordance with the voluntary buyout program(s) and other regulatory requirements • Identify and recommend property acquisition to transfer the levee to the appropriate and designated owner for future repair, maintenance and improvements • Identify appropriate funding sources that do not limit the future repair, maintenance and improvements to the levee system • Provide active coordination and education of property owners and stakeholders as to the needs for the area to provide resilience to future flood events
9.2.1.3 Floodproofing After the April 2013 flood event, six properties were identified as potential candidates for floodproofing through elevation of the structure. These six properties were submitted as part of DuPage County’s CDBG-DR application and are currently allocated for funding as part of the disaster recovery grant funds. There are other properties in this area that could be benefitted from a variety of floodproofing methods. Actual methods would have to be coordinated with the Village of Lisle to determine if the method is acceptable under the National Flood Insurance Program.
It is recommended that DuPage County and Lisle do the following regarding floodproofing:
• Establish and improve available resources (online, print, seminars, etc.) for home and business owners • Investigate grant and other funding opportunities to provide assistance for floodproofing • Investigate development of a municipal or countywide financial match for floodproofing
9.2.1.4 Education and Outreach The existing levee system is in need of repair, maintenance and improvements to match the original design elevations and intent. However, the levee was originally only designed to provide protection for up to a 50-year flood event. Even after levee repairs, the area would still potentially be subject to flooding during larger events. It is crucial to provide meaningful education to those protected by the levees in order to be able to anticipate, react to and recover from future large flood events. Educational opportunities can provide the opportunity to minimize the effects of the disaster.
In addition to recommended actions in Section 9.1.4.1, it is recommended that DuPage County and other stakeholders develop an educational outreach program that includes:
• Comprehensive understanding of the levee system and flooding including site field trips to show drainage and stormwater infrastructure • Develop and provide training sessions for an Emergency Action Plan for this area
9.2.2. Local Projects
140
9. Recommended Action Plan
A current list of local flood risk reduction projects scheduled to be completed within the next five years is in Table 9-x.
Table 9-X Planned Local Flood Risk Reduction Projects
Project Name Funding Entity / Subwatershed Cost Plan Westlake Concrete Drainage Channel Village of Bloomingdale $115,000 Repair FY2014/2015 Budget Indian Lakes Open Space Area Village of Bloomingdale $23,700 FY2014/2015 Budget Streambank Stabilization, St Joseph Downers Grove $8,000 Creek, North Branch CIP FY2015-FY2019
Streambank Improvements, St Joseph Downers Grove $825,000 Creek, South Branch CIP FY2015-FY2019
Streambank Improvements, St Joseph Downers Grove $300,000 Creek, Main Branch CIP FY2015-FY2019
Drainage Improvements - Cumnor Rd Downers Grove $50,000 between Sheldon and Chicago CIP FY2015-FY2019
Valley View Pond Improvements Downers Grove $60,000 CIP FY2015-FY2019
Existing Drain Tile Investigation Downers Grove $50,000 CIP FY2015-FY2019 Prentiss Creek (Sub E), Kensington Downers Grove $20,000 Place Online Storage CIP FY2015-FY2019
Watershed Improvements, Lacey Creek, Downers Grove $1,486,000 Sub G CIP FY2015-FY2019
PW Parking Lot Reconstruction Downers Grove $50,000 CIP FY2015-FY2019
Watershed Improvements, St Joseph Downers Grove EBSJ $250,000 Creek, North Branch Sub E CIP FY2015-FY2019
Neighborhood Drainage Improvements Downers Grove $250,000 Cost-Share Program CIP FY2015-FY2019
Drainage Improvements, Clyde Estates Downers Grove $550,000 CIP FY2015-FY2019
Headwall Replacement, Gilbert and Downers Grove $60,000 Brookbank CIP FY2015-FY2019
Drainage Improvements at Fire Station Downers Grove $2,000 #3 CIP FY2015-FY2019
141
9. Recommended Action Plan
Project Name Funding Entity / Subwatershed Cost Plan Lacey Creek (Sub G) - 35th St. between Downers Grove $10,000 Saratoga and Venard CIP FY2015-FY2019
Green Streets/Sustainable Storm Water Downers Grove $325,000 Program CIP FY2015-FY2019
Storm Sewer Replacement, Annual Downers Grove $2,500,000 Element CIP FY2015-FY2019
Downtown Business District Water Downers Grove $250,000 Quality Enhancements CIP FY2015-FY2019
Headwall Replacement, Grand at 55th Downers Grove $115,000 St. CIP FY2015-FY2019
Identified Future Drainage and Downers Grove $8,450,000 Floodplain Improvements CIP FY2015-FY2019
Storm Water Related Land Acquisitions Downers Grove $1,265,000 CIP FY2015-FY2019 Sanitary Sewer Lining – Location to be Lisle $625,000 determined annually Budget FY 2014/2015 Sewer Point Repairs Lisle $125,000 Budget FY 2014/2015 Storm Sewer Lining – Various locations Lisle $25,000 Budget FY 2014/2015 Levee Improvements – East Branch Lisle $100,000 DuPage River Budget FY 2014/2015 FEMA Grant Program for Lisle $1,000,000 acquisition/elevation of flood properties Budget FY 2014/2015 Future Stormwater Related Projects Lisle $2,000,000 Budget FY 2014/2015 Backyard Flooding Prevention Program Lombard $200,000 Capital Improvement Plan 2014-2023 Overhead Sewer Grant Program Lombard $450,000 Capital Improvement Plan 2014-2023 Sewer Maintenance and Improvements Lombard $1,800,000 Capital Improvement Plan 2014-2023 Sanitary Sewer Lining Program Lombard $675,000 Capital Improvement Plan 2014-2023 Sewer Stub Lining Program Lombard $475,000 Capital Improvement Plan 2014-2023 Clear Water Disconnect Grant Program Lombard $675,000 Capital Improvement Plan 2014-2023
142
9. Recommended Action Plan
Project Name Funding Entity / Subwatershed Cost Plan Backyard Sewer Lining Program Lombard $100,000 Capital Improvement Plan 2014-2023 Sanitary Sewer Upgrade - Prairie Lombard $294,300 (LaLonde – Grace) Capital Improvement Plan 2014-2023 Finley Road Sewer Lining Lombard $467,000 Capital Improvement Plan 2014-2023 Route 53 Stormwater Pump Station Lombard $5,340,900 Capital Improvement Plan 2014-2023 Lift Station, Rebuild - Fairview Lombard $1,410,100 Capital Improvement Plan 2014-2023 International Village Sewer Lining Lombard $416,000 Capital Improvement Plan 2014-2023 N. Broadway Interim Pump Station & Lombard $2,089,750 Force Main Capital Improvement Plan 2014-2023 Terrace View Pond - South East Outfall Lombard $42,500 Repair Capital Improvement Plan 2014-2023 Gatz Pond Outfall Lombard $2,813,500 Capital Improvement Plan 2014-2023 Route 53 Underground Improvements Lombard $2,223,600 Capital Improvement Plan 2014-2023 Lake Ellyn Outlet and Downstream Village of Glen Ellyn $455,000 Improvements Annual Budget 2015 Capital Program Geneva Road Culvert Extension Village of Glen Ellyn $35,000 Annual Budget 2015 Capital Program Village Green Storm Sewer Village of Glen Ellyn $75,000 Replacement Annual Budget 2015 Capital Program Reno Center Access Improvements Village of Glen Ellyn $50,000 Annual Budget 2015 Capital Program Miscellaneous Storm Sewer Village of Glen Ellyn $50,000 Improvements Annual Budget 2015 Capital Program Stormwater Improvements Village of Glen Ellyn $1,500,000 Annual Budget 2015 Capital Program Replace Basin #4 Flowmeters Wheaton $250,000 Five Year Financial Forecast
143
9. Recommended Action Plan
Project Name Funding Entity / Subwatershed Cost Plan Replace all Lift Station Standby Wheaton $125,000 Generators Five Year Financial Forecast Lift Station Mechanical Appurtenances Wheaton $89,000 Five Year Financial Forecast Lift Station Submersible Pumps Wheaton $89,000 Five Year Financial Forecast Supplemental Sanitary Sewer - Wheaton $625,000 Rehabilitation Lining Five Year Financial Forecast Supplemental Storm Sewer - Wheaton $625,000 Rehabilitation Lining Five Year Financial Forecast Sanitary Sewer Capacity Assurance Wheaton $12,100,000 Program Five Year Financial Forecast Cumnor Rd Design-GREEN Additional Village of Westmont $737,000 Cost Annual Budget FY 2014- 2015 Wilmette Design-GREEN Additional Village of Westmont $12,900 Cost Annual Budget FY 2014- 2015 60th St. Streambank Stabilization Village of Westmont $15,000 Eng/Insp Annual Budget FY 2014- 2015 35th St./Oakwood Dr Drainline Village of Westmont $91,940 Annual Budget FY 2014- 2015 Deer Creek Detention Basin Repairs Village of Westmont $25,000 Annual Budget FY 2014- 2015 61st & Cumnor Pond Beautification Village of Westmont $13,000 Project Annual Budget FY 2014- 2015 Land Acquisition Village of Westmont $800,000 Annual Budget FY 2014- 2015 Crabtree Creek Erosion Control Village of Woodridge $265,000 Capital Projects 5 Year Plan Lining Corrugated Metal Pipe and Village of Woodridge $250,000 Repairs Capital Projects 5 Year Plan Prentiss Creek Erosion Control Village of Woodridge $150,000 Capital Projects 5 Year Plan Streambank Stabilization Village of Woodridge $150,000 Capital Projects 5 Year Plan
144
9. Recommended Action Plan
Project Name Funding Entity / Subwatershed Cost Plan Lining of Sanitary Sewers Village of Woodridge $300,000 Capital Projects 5 Year Plan 63rd Street Storm Sewer Inlets Village of Woodridge $45,000 Capital Projects 5 Year Plan
9.2.3. Reserved This section is currently reserved for future use. 9.3. Non-Point Source Pollution Control Plan A Prioritized Action Plan has been developed for the East Branch DuPage River Watershed to provide stakeholders guidance on action items for watershed improvement practices. The Prioritized Action Plan serves as a “roadmap” for the implementation of the watershed-based plan and includes recommended watershed-wide and site specific best management practices (BMPs), a prioritized schedule for the implementation of the BMPs, recommendations on agencies and organizations responsible for plan implementation, and estimated BMPs costs.
The Prioritized Action Plan is divided into three subsections:
• Programmatic Action Plan • Site Specific Action Plan • Education and Outreach Plan
The Non-Point Source Pollution Programmatic Action Plan (Section 9.3.1) is focused on watershed-wide action items that are not site specific while the Site Specific Action Plan (Section 9.3.2) identifies specific and actual locations where water quality, hydrological modification, and/or flood reduction/prevention projects can be implemented. For each Watershed-wide and Site Specific recommendation a priority ranking was assigned. Additionally, estimated costs and responsible entities for project implementation are also provided.
Section 9.3.3 includes the Education and Outreach Plan. The Education and Outreach Plan highlights recommended actions that will need additional outreach and education in order to be implemented.
The six most important recommendations are summarized as follows:
1. Remediate existing flood problems and prevent future flooding by reducing stormwater runoff and restoring areas for surface water storage and absorption such as floodplains, depressional storage areas, and wetlands, which also provide water quality improvement benefits.
145
9. Recommended Action Plan
2. Restore and manage stream corridors by restoring native riparian buffers, removing excessive debris, and stabilizing the streambed and streambanks with practices that also enhance habitat.
3. Use better stormwater management and low impact development practices for new and existing development that slow, filter, infiltrate, cool, and cleanse stormwater runoff.
4. Modify and use planning and development standards, policies, and capital improvement plans and budgets to protect and enhance water quality.
5. Provide public education and outreach to enhance understanding and appreciation of watershed resources and problems and to provide opportunities for people to get involved in watershed improvement activities.
6. Monitor and evaluate watershed plan implementation and physical watershed conditions to gauge progress towards watershed goals.
9.3.1. Non-Point Source Reduction Programmatic Action Plan The Programmatic Action Plan includes recommended BMPs that are applicable watershed- wide and has been divided into two sections. The first section is focused on recommendations that are applicable across the East Branch watershed to meet the overall goals identified in this Plan. The second section provides a review of the existing ordinances applicable in the watershed and provides recommendations for changes aimed at improving water quality, stream health and the reduction of flooding in the watershed.
The Programmatic Plan is focused on five non-point source reduction and water quality improvement strategies for the East Branch DuPage River watershed:
A. Protect and enhance overall surface and groundwater quality in the East Branch DuPage River Watershed.
B. Reduce flood damages in the watershed and prevent flooding from worsening with climate change.
C. Improve aquatic and wildlife habitat in the East Branch DuPage River watershed.
D. Protect additional open space in the East Branch watershed that can provide multiple benefits including flood storage, and recreational and educational opportunities.
E. Increase coordination between decision makers and other stakeholders in the watershed.
F. Raise stakeholder awareness (residents, public officials, etc) about the importance of best management practices and watershed stewardship.
146
9. Recommended Action Plan
The Programmatic Action Plan is presented in table format (Tables X-X). The Programmatic Action Plan table has been broken down into the recommended action item/BMP, priority, cost, responsible lead agencies or organization with greatest potential to implement the recommendation, and support agencies or agencies who could assist with technical, financial, or regulatory assistance or whose programs may be impacted by the recommendations. Each recommendation is given a unique ID number (ID#).
Cost estimates are only provided for best management practices that involve construction or engineering costs such as streambank stabilization, native plantings, and feasibility studies. Costs are not included for preventative measures such as outreach and educational programs or regulatory actions. The cost estimates are included for advisory purposes only. The cost estimates are concept level costs and are most useful to compare the relative costs of the recommended BMPs. More detailed costs should be developed when site constraints are more fully investigated and preliminary engineering is conducted.
Each of the BMPs was assigned a priority status and classified as high (H), medium (M), or low (L). Priority status was assigned based on need, cost, potential funding opportunities, and technical needs. High priority action items should be considered short-term goals (1-5 years) while medium and low priority action items are considered long-term goals (greater than 5 years).
Summary of Programmatic Plan’s non-point source reduction and water quality improvement strategies and tactics
Strategy A: Protect and enhance overall surface and groundwater quality in the East Branch DuPage River Watershed.
Tactics
1. Implement stormwater best management practices (BMPs) throughout the watershed to improve water quality by reducing nonpoint source pollution.
2. Restore riparian buffers along the East Branch DuPage River and its tributaries where possible within the context of existing development. The buy-out areas may offer strategic opportunities to restore riparian buffers.
3. Protect additional green open space focused on multiple benefits and increased watershed resiliency. Areas identified as priority in the DuPage County Open Space and Natural Areas Plan can be assessed in conjunction with where natural ecosystem services including runoff storage and infiltration are most needed.
Protection and improving water quality through the use of stormwater BMPs, and the preservation and restoration of the natural drainage system (overland flow paths, streams, and floodplain) should be required in all new development and re-development. Drainage and detention in existing developed areas should be retrofitted or repaired to better control runoff rates and volume as well as to improve water quality. Older facilities tend to be designed only
147
9. Recommended Action Plan
for detention, and not for water quality and volume control. Natural and existing drainageways should also be preserved and/or restored to the extent practicable as part of the green infrastructure network and to reduce the impacts of hydrologic modification within the watershed.
All landowners and stakeholders within the watershed have the ability to improve water quality by managing land and property to prevent or remove pollutants in runoff before they are washed into the stream. The implementation of stormwater BMPs is the responsibility of all landowners (for existing development) and developers and builders (for new development). However, municipalities must require or encourage these practices to be installed. Preservation of remaining natural drainage and storage features of the landscape is the responsibility of the private and public land owners.
Strategy B: Reduce flood damages in the watershed and prevent flooding from worsening with climate change.
Tactics
1. Mitigate for existing flood damage by identifying those parcels suitable for flood mitigation projects and those qualifying for buy-outs, as unmet needs.
2. Reconnect channelized stream segments to the floodplain where feasible.
3. Implement stormwater best management practices (BMPs) throughout the watershed designed to reduce runoff and encourage infiltration.
4. Protect undeveloped floodplain from development.
5. Address levee integrity insufficiencies.
6. Address drainage in adequacies in areas behind the levee.
Flooding and risk of flooding occurs throughout the East Branch DuPage River watershed. The flooding and increased flood risk is primarily a result of historical development within the floodplain and increased runoff from urban development. The changes in land use, particularly prior to the DCCFPO, lead to modifications to the floodplain and wetland areas, increased impervious surfaces, and increased rate and volume of stormwater runoff.
Strategy C: Improve aquatic and wildlife habitat in the East Branch DuPage River watershed.
Tactics
1. Identify opportunities for improving habitat along degraded stream channels using a natural channel design.
2. Identify opportunities for wetland restoration, creation and preservation within the watershed based on the DuPage County Open Space and Natural Areas Plan.
148
9. Recommended Action Plan
3. Restore riparian buffers along the East Branch DuPage River and its tributaries.
4. Encourage local residents to utilize native species in their landscapes.
5. Identify opportunities for habitat improvements at parks and natural areas.
6. Protect through various mechanisms additional strategically location open space based on the DuPage County Open Space and Natural Areas Plan. These areas should expand existing core habitat areas and provide corridor connections between them for greater connectivity and adaptation to climate change.
Streambank erosion is threatening property, damaging infrastructure, and degrading water quality and riparian habitat. Stabilization, restoration and management of the stream channel, streambank and riparian corridor are needed throughout the watershed to improve water quality, maintain floodplain functions, and improve aquatic and wildlife habitat both within and near the streams. Practices that are needed include restoring in-stream habitat such as pools and riffles, removing excessive debris from the stream channel, establishing naturalized streambanks with native plants, and managing stream corridors by restoring native riparian buffers where possibly in the highly urbanized landscape of this watershed.
Through easement agreements or ownership, most private landowners are responsible for maintaining the stream and riparian zone as it crosses their property or flows along a property line. This includes all aspects of management and maintenance including debris removal, stabilization of streambanks, and management of private stormwater outfall pipes such as sump pumps and downspouts. Exceptions to the private landowner responsibility exist where the stream flows through publically owned lands such as parks and within right-of-way easements. As problems within the stream and riparian corridor are directly related to land use and other activities upstream in the watershed, it is important that all landowners living within the watershed (not just those living adjacent to the creek) work together on implementing the watershed-based plan.
Strategy D: Protect additional open space in the East Branch watershed that can provide multiple benefits including flood storage, and recreational and educational opportunities.
Tactics
1. Based on the DuPage County Open Space and Natural Areas Plan, identify and protect open space along the East Branch and its tributaries that would provide opportunities to restore natural floodplain storage and riparian functions.
2. Identify and protect open space aimed at protecting and preserving natural resources.
3. Identify and protect areas that can be used for multiple uses (trails, passive recreation).
149
9. Recommended Action Plan
4. Encourage private landowners to install filter strips or riparian buffers along stream corridors.
There are approximately 10,040 acres (21.6% of the watershed) of open space, parks, and forest preserves in the watershed. Open space and natural areas such as stream and riparian corridors, wetlands, and parks that remain undeveloped provide storm and flood water protection, serve as natural buffers for streams, and serve as passive and active recreational spaces for residents and visitors to the watershed. As such it is important for the watershed- based plan to identify ways of restoring/creating naturalized open space and improving access to creeks for recreational activities.
Green infrastructure includes all the interconnected natural systems in a landscape, such as intact forests, woodlands, wetlands, parks and rivers, or agricultural soils that provide clean water, air quality, wildlife habitat and food. By considering these natural systems as part of the ‘infrastructure,’ we can begin to assign appropriate values to them. They are important to our lives and livelihoods, and the resiliency of the watershed. They provide stormwater treatment, energy savings, aesthetic values, improved community health and a sustainable local economy. Green infrastructure also includes man-made, best management practices that are designed to mimic and complement the characteristics of natural systems. Combined, the existing natural ecosystems and BMPs constitute the green infrastructure network. A connected green infrastructure network across the watershed will greatly improve resiliency.
Strategy E: Increase coordination between decision makers and other stakeholders in the watershed.
Tactics
1. Encourage communities to adopt the this Plan.
2. Encourage the adoption and/or revision of comprehensive plans and ordinances that support the watershed plan’s goals and objectives.
3. Encourage communities to continue to be active members of the working groups and committees established by DuPage County for the East Branch watershed.
Activities in one area of the watershed can impact water resources in another part of the watershed even when those areas seem distant and unconnected. And subsequently, the actions of all those living within the watershed have impacts, whether negative or positive, on the health of East Branch and its tributaries. As such, the participation and coordination of all watershed stakeholders is necessary for water quality and habitat improvements and flood damage reduction in the watershed. No single person, municipality or entity can effectively implement the watershed-based plan alone.
Many of the recommendations in the plan require technical expertise and require significant funding to implement. As such, coordination across property and jurisdictional lines is vital for the successful implementation of the plan. By working together, stakeholders can share
150
9. Recommended Action Plan
expertise and equipment making projects that one entity could not do alone feasible. Additionally, available monies can be combined and leveraged for maximum benefits.
Strategy F: Raise stakeholder awareness (residents, public officials, etc) about the importance of best management practices and watershed stewardship.
Tactics
1. Provide watershed stakeholders with an outreach plan that gives them the knowledge needed to help implement the watershed plan.
2. Develop an urban outreach program for communities that will focus on stormwater management. This may include rain gardens, bioswales, and rainwater capturing.
3. Promote conservation programs for corporate campuses, office complexes, and other large landowners including providing meetings and tours to showcase BMPs.
4. Promote the “health of the watershed” concept to all watershed stakeholders.
5. Encourage the acceptance of buy-outs and flood proofing for eligible landowners within the watershed.
Even the best plan for managing watersheds, controlling nonpoint source pollution, and reducing flooding cannot succeed without community participation and cooperation. An aggressive public outreach and education program, therefore, is essential and must be nurtured. Because many water quality problems result from individual actions and the solutions are often voluntary practices, effective public involvement and participation to promote the adoption of management practices is necessary. The needed public buy-in and support is impossible unless stakeholders understand their role in watershed protection and restoration and are willing to make changes in their behavior that will help achieve overall watershed goals. A well designed and implemented education and outreach plan is necessary to facilitate changes in stakeholders’ opinions and actions.
Table 9-x Watershed-wide Non-Point Source Reduction Programmatic Action Plan for the East Branch DuPage River watershed
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
151
9. Recommended Action Plan
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
1 Watershed- Continue to support the wide ongoing water quality monitoring programs aimed at assessing the current condition of the East Branch A H S n/a DuPage River watershed and to assess changes in water quality associated with the implementation of this watershed-based plan. 2 Watershed- Develop a Riparian wide Landowner Handbook to A, B. $5,000- educate riparian landowners L L C $20,000 on their responsibilities and easement requirements. 3 Watershed- Implement a waterside-wide $20 per wide stream maintenance A, B, M M linear program to remove debris C foot and blockages routinely. 4 Watershed- Inventory, then repair or wide retrofit problematic or undersized hydraulic structures with priority in A, B H S the most affected/most distressed portions of the watershed. 5 Watershed- Complete detailed inventory wide of all detention and retention basins in the watershed to document $5,000- A, B H S storage capacity, vegetation, $7,000 maintenance needs, etc to identify potential retrofit opportunities. 6 Watershed- Develop a maintenance plan wide for all detention and retention basins in the watershed to ensure effective operation and provide maximum A, B M M n/a detention, water quality benefit, and habitat. The plan should identify who is responsible, a maintenance schedule, budget and funding source.
152
9. Recommended Action Plan
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
7 Watershed- Utilize naturalized detention wide basins in new development and retrofit existing single function dry bottom detention basins to provide multiple benefits including A, B, M M varies reducing pollutant loads and C improving habitat. Upgrade and maintain existing basins to provide water quality benefits and slower release rates. 8 Watershed- Stabilize eroding detention wide pond shorelines and replace A, C riprap, concrete, and turf with native vegetation. 9 Watershed- Develop stream restoration wide guidelines to provide guidance to riparian landowners on methods of $5,000- A, C M M streambank stabilization, $20,000 riparian buffer restoration, and other bioengineering techniques. 10 Watershed- Encourage enrollment in the wide Conservation @ Home A, C, program, especially in M S n/a D riparian and floodplain areas of the watershed. 11 Watershed- Promote stormwater BMPs wide for handling residential stormwater including downspouts and sump A, B H S varies pumps. Flow should be directed onto a lawn or areas landscaped with native vegetation. 12 Watershed- Develop consistent wide education and outreach materials for use across the A, B M M n/a watershed emphasizing BMPs, green infrastructure, and resiliency. 13 Watershed- When replacing pavement wide use pervious or porous $2 to $6 pavement or permeable per A, B M M pavers where appropriate to square increase infiltration and foot reduce runoff volumes. 153
9. Recommended Action Plan
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
14 Watershed- Retrofit roadways and $40-$60 wide parking lots to allow per stormwater to enter A, B L L square infiltration BMPs (rain yard gardens, swales, etc). 15 Watershed- Where feasible, convert $40-$60 wide existing swales and open A, B, per drainageways to infiltration M M C square BMPs with native yard landscaping. 16 Watershed- Encourage the wide implementation of stormwater BMPs in new developments and in A, B H S varies redevelopment projects above the minimum requirements. 17 Watershed- Encourage the wide implementation of stormwater BMPs in new developments and in B H S varies redevelopment projects above minimum amount required. 18 Watershed- Identify flood mitigation wide opportunities in the watershed for creating B L L varies additional storage and/or improving the local drainage. 19 Watershed- Create/restore wetlands and $10,000 wide depressional areas within to B M M the watershed. $60,000 per acre 20 Watershed- Identify locations where the wide incised stream channel can B L L varies be reconnected to the floodplain appropriately. 21 Watershed- Mitigate flood damages by wide floodproofing at-risk structures, encouraging buy- B H varies out acceptance for eligible structures. 22 Watershed- Restore instream and wide riparian habitat in conjunction with road and C M M Varies bridge improvement projects.
154
9. Recommended Action Plan
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
23 Watershed- Provide information to wide residents and business C H S n/a owners on the benefits of native landscaping. 24 Watershed- Where feasible, daylight and wide re-meander streams that $575 per have been contained in C L L linear ditches or moved foot underground into culverts and pipes. 25 Watershed- For severely eroded stream wide reaches, develop a stream C M M varies restoration plan and cost estimate. 26 Watershed- Establish native riparian wide buffers along unbuffered or $12-$25 inadequately buffered C, D H S per linear stream reaches where foot possible. 27 Watershed- Based on the DuPage wide County Open Space and Natural Areas Plan, identify and protect open space parcels along the East $5,000- D M M Branch and its tributaries $20,000 that would provide opportunities to restore natural floodplain storage and riparian functions. 28 Watershed- Identify and protect open wide space aimed at protecting D M M varies and preserving the natural resources of the watershed. 29 Watershed- Identify and protect areas wide that can provide multiple functions (ecosystem services) such as infiltration, water quality improvements, D H S n/a wildlife habitats, natural flood storage, and recreation/education opportunities. 30 Watershed- Identify opportunities for wide municipalities to encourage the use of green D H S n/a infrastructure and open space preservation in new developments.
155
9. Recommended Action Plan
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
31 Watershed- Encourage the adoption of wide the Watershed-Based Plan E H S n/a by all jurisdictions located in the watershed. 32 Watershed- Continue to meet as the wide Watershed Steering Committee in order to E H S n/a facilitate plan implementation and conduct progress evaluations. 33 Watershed- Work collaboratively to wide obtain HUD NDRC and 319 funding to implement E H S n/a actions in this watershed plan. 34 Watershed- Incorporate the watershed- wide based plan’s goals, objectives, and E H S n/a recommendations in to municipal codes, regulations and comprehensive plans. 35 Watershed- Provide training and wide educational outreach to municipal officials and engineers on the goals, E H S n/a objectives, recommendations, and implementation of the watershed-based plan. 36 Watershed- Provide training and wide educational outreach to municipal officials and engineers on the goals, F H S n/a objectives, recommendations, and implementation of the watershed-based plan. 37 Watershed- Promote Conservation @ wide Home with homeowners on F M M n/a native landscaping and other stormwater BMPs. 38 Watershed- Maintain an East Branch wide watershed planning website to keep the public informed F H S n/a on plan implementation activities. 39 Watershed- Hold watershed workshops wide in parks and other open F M M n/a spaces. 156
9. Recommended Action Plan
ID Project Location Recommendation / BMP Status
# Lead Cost Agency Agency Priority Strategy Timeframe Supporting
40 Watershed- Educate riparian property wide owners on ways to improve riparian conditions for flood F H S n/a storage, water quality and habitat. 41 Watershed- Educate homeowners wide associations, developers, and municipalities about the importance of protecting F H S n/a open space, incorporating stormwater BMPs, and maintenance strategies for existing BMPs.
9.3.1.1 Regulatory Review and Recommendation The review of regulatory ordinances related to water quality and stormwater management is a recommended action to be conducted as part of the preparation of this plan as means of obtaining IEPA approval as a “watershed-based” plan.
9.3.2. Non-Point Source Reduction Site Specific Plans In addition to the programmatic recommendations, which generally apply watershed wide, site- specific action items and recommendations are tied to a particular location in the watershed. As with the programmatic actions, these site specific recommendations were developed to address watershed problems, to improve watershed resources, and to achieve the watershed goals and objectives.
The process of identifying specific sites that are in need of, or suited to, watershed improvement projects has been ongoing during the planning process and will continue throughout plan implementation.
The Site Specific Plan includes a multitude of projects including streambank stabilization and restoration, detention pond retrofits, green infrastructure, open space restoration and preservation, and other projects. The Site Specific Plan is summarized in table format by type of project (Tables X-X to X-X). The provided cost estimates are included for advisory purposes only. The cost estimates should be interpreted only as concept costs and are best used to compare the relative costs of the recommended BMPs. More detailed costs can be developed once site constraints and additional conceptual or preliminary engineering activities are conducted. Funding for these projects will likely come from state and federal grants and local sources.
157
9. Recommended Action Plan
9.3.2.1 Streambank Stabilization and Restoration Projects Section currently being updated.
9.3.2.2 Detention Basin Retrofits. Section currently being updated.
9.3.2.3 Green Infrastructure Section currently being updated.
9.3.2.4 Open Space Preservation and Restoration Section currently being updated.
9.3.2.5 Additional Projects Section currently being updated.
9.3.3. Non-Point Source Reduction Education and Outreach Plan Section currently being updated.
158
10. Plan Implementation & Evaluation This chapter identifies a strategy for moving from planning to implementation of the action plan recommendations. How frequently this plan is used and implemented by watershed stakeholders is one indicator of its success. Improvement in water quality and watershed resources, the reduction of nonpoint source pollution, and the reduction of flooding is also an important indicator. Successful plan implementation will require significant cooperation and coordination among watershed stakeholders to secure project funding and to efficiently and effectively move the action plan from paper to the watershed.
This chapter also relates some more technical details about the expected results of putting action recommendations in place. It presents a plan for monitoring and evaluating plan implementation as a way to determine progress towards meeting the watershed goals and objectives. 10.1. Implementation Process Discuss how this plan provides background information and will enable stakeholders to use this plan for future permitting, grant applications, etc. 10.2. Stakeholder Engagement DuPage County is planning on continuing stakeholder engagement and outreach through a variety of methods including public meetings, steering committee meetings, stakeholder meetings, website updates, social media updates, and other methods. More information is being prepared on future engagement opportunities. 10.3. Implementation Roles & Responsibilities Successful plan implementation is dependent on watershed stakeholders forming partnerships as a means of maximizing efforts to complete watershed projects. Key stakeholders that have potential to form watershed partnerships for the implementation of the watershed plan are listed in Chapter 5 Section 2. These and other stakeholders are encouraged to:
• Acquire funding through grants and other means; • Implement educational programs; • Sponsor and participate in water quality sampling; • Provide technical and regulatory guidance; • Maintain and monitor water quality improvement projects; and • Update and amend the watershed plan as changes occur.
10.3.1. Conservation Strategies Additional discussion is being prepared.
10.3.2. Jurisdictional Strategies Additional discussion is being prepared.
159
10. Plan Implementation & Evaluation
10.3.3. Other Stakeholder Strategies Additional discussion is being prepared. 10.4. Implementation Schedule More detail regarding an implementation schedule is currently being prepared.
10.5. Funding Sources A discussion on funding sources is currently being prepared.
10.6. Interim Milestones & Progress Evaluations Discussion on milestones and evaluations is being prepared. 10.7. Hydrologic Additional discussion is being prepared. 10.8. Data Collection & Analysis Continued monitoring - observing and tracking watershed conditions for both positive and negative changes that are a result of the implementation of the plan - is essential for providing feedback on the progress of the implementation of this watershed-based plan. If no correlation between water quality improvement and flood damage reduction, and implementation of this Plan can be determined and/or progress is not being made towards reaching the goals of the plan, DCWSC, as the implementation leader, should consider whether the recommended strategies are having the desired effect or if the plan should be updated and modified.
Recommendations that are physical or structural in nature such as streambank stabilization, the construction of infiltration BMPs, and restoring riparian buffers, can be assessed in terms of the reduction of pollutant loads discharged into the watershed, improved biological and habitat health, and the degree of change in stormwater runoff volume and flow. The effectiveness of non-structural recommendations such as the implementation of education/outreach programs, stream maintenance programs, and changes to policies and regulations are much more difficult to monitor. Changes in behavior following the implementation of non-structural recommendations can be assessed by gathering feedback through meetings with watershed stakeholders and tools such as surveys and focus groups.
The monitoring strategy recommended for the East Branch watershed is intended to help track and measure the implementation of recommendations made in this plan using a variety of indicators that are monitored regularly, typically on an annual basis or every three years. Progress on overall plan implementation should be reviewed using the milestones and indicators every 5 years and the plan should be updated as needed.
Since watershed issues, opportunities, and regulatory context will change over time, this watershed-based plan should be evaluated and updated every five years so that completed projects can be removed from the plan and new projects added based on conditions and 160
10. Plan Implementation & Evaluation priorities. In addition to this 5-year update, plan implementation should be monitored annually by the DuPage Watershed Steering Committee. At the time of the annual evaluation, the committee should assess the list of priorities and identify the top priority actions for the following year. 10.9. Flood Forecasting & Watershed Resilience The East Branch DuPage River must implement a flood forecasting system through the installation of additional precipitation and stream gauges. This will create the basis for an early warning system that can be used to notify and alert municipalities who serve the highest risk populations. This gauging system will also serve to evaluate risk over time. If no action is taken, flood risk is expected to increase over time. Without gauging to measure the response of the watershed, it will be impossible to fully understand this dynamic risk. In particular, the forecasting system will help to define how watershed management projects are managing risk in the watershed. With a successful implementation plan, the forecasting system should show that despite more frequent severe precipitation events, the overall flood risk in the watershed is reduced over time.
161
11. References A list of references is currently being prepared for the Plan.
162
12. Exhibits Exhibit 1 Overview of Watershed
Exhibit 2 Jurisdictions
Exhibit 3 Transportation Network
Exhibit 4 East Branch DuPage River Subwatersheds
Exhibit 5 DuPage County 2-foot Topography
Exhibit 6 Soil Series in the East Branch DuPage River Watershed
Exhibit 7 Coverage of Hydric Soils in the East Branch DuPage River Watershed
Exhibit 8 Highly Erodible Soils in the East Branch DuPage River Watershed
Exhibit 9 Hydrologic Soil Groups in the East Branch DuPage River Watershed
Exhibit 10 Historic Places/Districts in the East Branch DuPage River Watershed
Exhibit 11 Forest Preserves in the East Branch DuPage River Watershed
Exhibit 12 Wetlands in the East Branch DuPage River Watershed
Exhibit 13 100-year Floodplains
Exhibit 14 NPDES Point Source Discharges
Exhibit 15 Sampling Sites
Exhibit 16 Existing Land Use in the East Branch DuPage River Watershed
Exhibit 17 Future Land Use in the East Branch DuPage River Watershed
Exhibit 18 Low to Moderate Income Census Tracts
Exhibit 19 Critical Facilities in the East Branch DuPage River Watershed
Exhibit 20 Heat Map of Damages from April 2013 Flood Event
Exhibit 21 Road Construction, Repairs, or Reconfigurations (Ongoing or Proposed, 2015- 2020) for Roads in the East Branch DuPage River Watershed
Exhibit 22 Identified Flood Problem Areas
13. Appendices Appendices are currently being prepared.
Appendix A Stakeholder Questionnaires
Appendix B Studies in the East Branch DuPage River Watershed
Appendix C Watershed Jurisdictions
Appendices
13.1. Appendix A: Stakeholder Questionnaires
Appendices
13.2. Appendix B: Other East Branch DuPage River Studies
Appendices
13.3. Appendix C: Watershed Jurisdictions