East Branch DuPage River Watershed & Resiliency Plan Prepare, React and Recover March 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 & & y E m nv o 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 1.1. The East Branch DuPage River Watershed ........................................................... 1 1.2. Goals of this Plan ................................................................................................... 1 1.3. How the Watershed Plan Helps the Community .................................................. 2 1.4. The Watershed Plan’s Recommendations............................................................. 2 2. Glossary ..................................................................................................................... 5 2.1. Agencies/Stakeholders .......................................................................................... 5 2.2. Municipalities ........................................................................................................ 8 2.3. Acts/Ordinances/Programs .................................................................................. 8 2.4. Terms ..................................................................................................................... 9 2.5. Watersheds, Subwatersheds and River Reaches................................................. 14 3. Introduction ............................................................................................................ 15 3.1. Watershed Planning Overview ............................................................................ 15 3.1.1. What is Watershed Planning? ................................................................................. 15 3.1.2. Watershed Planning for the East Branch DuPage River ......................................... 16 3.1.3. Resilience and Watershed Planning ........................................................................ 17 3.1.4. Addressing Unmet Needs in the East Branch DuPage River Watershed ................ 18 3.1.5. Statement of Plan Goals ...........................................................................................18 3.2. Watershed Planning Process & Data Collection ................................................. 20 3.2.1. Identifying Watershed Jurisdictions and Stakeholders ......................................... 20 3.2.2. Stakeholder Data Collection Process ...................................................................... 24 3.3. Watershed Physical and Water Quality Data ...................................................... 25 3.3.1. Flooding-Related Data & Analysis .......................................................................... 25 3.3.2. Demographics & Socioeconomic Data .................................................................... 26 3.4. Public Outreach & Stakeholder Engagement ...................................................... 26 i Contents 3.5. Plan Adoption ...................................................................................................... 28 4. Watershed Characteristics Assessment .................................................................. 29 4.1. The East Branch DuPage River Watershed ......................................................... 29 4.1.1. Mainstem of the East Branch DuPage River .......................................................... 30 4.1.2. East Branch Subwatersheds ................................................................................... 30 4.1.3. Channel Conditions ................................................................................................ 34 4.2. Climate and Precipitation .................................................................................... 34 4.2.1. Climate .................................................................................................................... 34 4.2.2. Precipitation............................................................................................................ 35 4.3. Geology and Topography ..................................................................................... 36 4.4. Soils ...................................................................................................................... 37 4.4.1. Soil Series ................................................................................................................ 37 4.4.2. Hydric Soils ............................................................................................................. 39 4.4.3. Soil Erodibility ........................................................................................................ 39 4.4.4. Soil Infiltration Capacities (Hydrologic Soil Groups)............................................. 40 4.5. Cultural Resources ............................................................................................... 42 4.6. Natural Resources ................................................................................................ 43 4.6.1. Illinois Natural Area Inventory Sites ...................................................................... 43 4.6.2. Parks, Forest Preserve Lands and Trails ................................................................ 44 4.6.3. Threatened and Endangered Species ..................................................................... 45 4.6.4. Wetlands, Riparian Areas, and Potential Wetland Restoration Sites .................... 46 4.7. Groundwater Resources ...................................................................................... 49 4.8. Agricultural Best Management Practices ............................................................ 50 4.9. Watershed Drainage, Hydrology & Hydraulics ................................................... 51 4.9.1. Stream Flow, Discharge & Baseflow Characteristics ............................................... 51 4.9.2. Channel Conditions ................................................................................................ 54 4.9.3. Hydraulic Structures ............................................................................................... 56 4.9.4. Stormwater Management Facilities ........................................................................ 58 4.10. Floodplains ....................................................................................................... 60 ii Contents 4.11. Water Quality ................................................................................................... 62 4.11.1. State of Illinois Water Quality Reporting ............................................................... 62 4.11.2. IEPA Permit Programs ........................................................................................... 66 4.11.3. Water Quality Monitoring Stations, Results and Trends ....................................... 69 4.11.4. Nonpoint Pollution Sources & Load Analysis ......................................................... 82 4.12. Critical Areas for Watershed Improvement ..................................................... 86 4.12.1. Critical Subbasins ................................................................................................... 87 4.12.2. Critical Stream Reaches .......................................................................................... 87 4.12.3. Summary and Conclusions ..................................................................................... 87 5. Land Use, Demographics and Transportation ....................................................... 91 5.1. Watershed Land Use and Land Cover ................................................................. 91 5.1.1. Historical Land Use ................................................................................................. 91 5.1.2. Current Land Use and Land Cover ......................................................................... 92 5.1.3. Future Land Use / Land Cover Projections ............................................................ 93 5.1.4. Land Use Impacts on the East Branch Watershed ................................................. 94 5.1.5. Impervious Area Analysis ....................................................................................... 95 5.2. Watershed Socioeconomic and Demographic Conditions .................................. 95 5.2.1. Population ............................................................................................................... 96 5.2.2. Income Profile & Low-Moderate Income Areas ..................................................... 98 5.2.3. Economic Activity & Industry Profile ................................................................... 100 5.2.4. Housing & Home Ownership ................................................................................. 101 5.2.5. Community Facilities ............................................................................................ 104 5.2.6. Community & Organizational Resources .............................................................. 105 5.3. Transportation ................................................................................................... 107 5.3.1. Existing Transportation Network & Issues .......................................................... 108 5.3.2. Proposed