Pecatonica River Total Maximum Daily Load and Load Reduction Strategies Stage 1 Report 1021 North Grand Avenue East P.O. Box 19276 Springfield, Illinois 62794-9276 Report Prepared by: Tetra Tech 1468 West 9th Street, Suite 620 Cleveland, OH 44113 and Fluid Clarity 1144 West Lake Street; Suite 303 Oak Park, Illinois 60301 February 18, 2014 Pecatonica River Watershed TMDL Stage 1 Report Contents Figures ........................................................................................................................................................ iii Tables.......................................................................................................................................................... iii Acronyms and Abbreviations .................................................................................................................... v 1. Introduction .................................................................................................................................... 1 1.1 TMDL Development Process .......................................................................................................1 1.2 Water Quality Impairments ..........................................................................................................2 2. Watershed Characterization ......................................................................................................... 6 2.1 Jurisdictions and Population.........................................................................................................6 2.2 Climate..........................................................................................................................................6 2.3 Land Use and Land Cover ............................................................................................................7 2.4 Topography.................................................................................................................................10 2.5 Soils ............................................................................................................................................10 2.6 Hydrology and Water Quality ....................................................................................................13 2.6.1 USGS Flow Data ..............................................................................................................13 2.6.2 Illinois EPA Water Quality Monitoring............................................................................17 3. Watershed Source Assessment .................................................................................................21 3.1 Pollutants of Concern .................................................................................................................21 3.2 Point Sources ..............................................................................................................................21 3.2.1 NPDES Facilities (Non-Stormwater)................................................................................21 3.2.2 Municipal Separate Storm Sewer Systems .......................................................................23 3.2.3 CAFOs ..............................................................................................................................23 3.3 Nonpoint Sources .......................................................................................................................24 3.3.1 Stormwater Runoff ...........................................................................................................25 3.3.2 Erosion..............................................................................................................................26 3.3.3 Onsite Wastewater Treatment Systems ............................................................................28 3.3.4 Animal Feeding Operations (AFOs).................................................................................28 4. TMDL Endpoints and LRS Targets.............................................................................................30 4.1 Applicable Standards..................................................................................................................30 4.1.1 Designated Uses................................................................................................................30 4.1.2 Water Quality Criteria ......................................................................................................30 4.2 Load Reduction Strategy Targets ...............................................................................................31 4.2.1 Phosphorus........................................................................................................................32 4.2.2 Total Suspended Solids, Sedimentation, and Siltation .....................................................32 5. Data Analysis................................................................................................................................34 5.1 Pecatonica River.........................................................................................................................34 5.1.1 PW-04 and PW-08 ............................................................................................................34 5.1.2 PW-01 and PW-13 ............................................................................................................36 5.2 Raccoon Creek (PWA-01)..........................................................................................................38 5.3 Coolidge Creek (PWF-W-C1) ....................................................................................................38 5.4 Winneshiek Creek (PWL-01) .....................................................................................................39 5.5 Yellow Creek (PWN-01) ............................................................................................................39 5.6 Spring Branch (PWNC)..............................................................................................................40 -ii- Pecatonica River Watershed TMDL Stage 1 Report 5.7 Lake Le-Aqua-Na (RPA)............................................................................................................41 6. TMDL Methods and Data Needs .................................................................................................44 6.1 Stream Impairments....................................................................................................................44 6.1.1 Load Duration Curve Approach........................................................................................44 6.1.2 Qual2K..............................................................................................................................46 6.2 Lake Impairments.......................................................................................................................47 6.3 Additional Data Needs................................................................................................................47 7. References....................................................................................................................................50 Figures Figure 1-1. Two impaired waters in the Pecatonica River project area ........................................................1 Figure 1-2. Pecatonica River watershed. ......................................................................................................3 Figure 1-3. Pecatonica River watershed, TMDL/LRS project area. .............................................................4 Figure 2-1. Pecatonica River project area land use (2006 National Land Cover Database).........................9 Figure 2-2. Pecatonica River project area land elevations (2012 National Elevation Dataset, USGS). .....10 Figure 2-3. Pecatonica River project area Hydrologic Soil Groups (Soil Surveys for Carroll, JoDaviess, Ogle, Stephenson, and Winnebago Counties, Illinois, USDA-NRCS) ..............................................12 Figure 2-4. USGS stream gages within project area...................................................................................15 Figure 2-5. Flow duration curves for the active USGS gages in the Pecatonica River study area. ............16 Figure 2-6. Daily flow in the Pecatonica River with daily precipitation at Freeport (113262), 1994. .......17 Figure 2-7. Illinois EPA water quality sampling sites within project area. ................................................18 Figure 3-1. CAFOs in the project area (EPA Envirofacts Permit Compliance System- Integrated Compliance Information System (PCS-ICIS) online, 2013)..............................................................24 Figure 3-2. Channel evolution model (from Simon and Hupp 1986). ........................................................27 Figure 5-1. TSS versus flow condition, PW-08. .........................................................................................36 Figure 5-2. Dissolved oxygen profiles at RPA-1, 2012..............................................................................42 Figure 5-3. Secchi depth measurements at RPA-1, 2012............................................................................42 Tables Table 1-1. Pecatonica River watershed impairments and LRS pollutants (2012 Illinois 303(d) Draft List) 5 Table 2-1. Total county populations .............................................................................................................6