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