Sediment and nutrient load model
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This document describes a modeling effort to quantify sediment and nutrient loads in the Lake Springfield watershed and prioritize conservation practices to maximize pollutant reductions. Key points: - A web-based watershed management tool was developed to track progress towards meeting TMDL nutrient reduction goals and prioritize practices based on their load reduction potential. - Crop runoff and tile drainage are major sources of nitrogen, phosphorus, and sediment loading to the lake. Conservation practices like no-till, cover crops, and filter strips were modeled. - The model estimates annual loads and potential load reductions from different conservation scenarios to help prioritize practices and evaluate progress towards water quality targets.
Sediment and nutrient load model
- 1. SEDIMENT & NUTRIENT LOAD MODELING Quantifying the Effects of Conservation Practices; an Interactive Web-based Management System to Prioritize Practice Placement & Maximize Pollutant Load Reductions Jeff Boeckler Northwater Consulting
- 2. OUTLINE Overview of Lake Springfield Watershed Water quality Watershed Plan & TMDL Pollution load model Demonstration of web-based management system/interface
- 3. WATER QUALITY NUTRIENT STANDARDS The Illinois phosphorus standard for reservoirs is 0.05 mg/L Almost no lake in Illinois meets this standard Drinking water standard for nitrate is 10 mg/L Lake Springfield 2008-2013 total phosphorus samples 66 out of 66 samples far exceeded 0.05 mg/L standard 2008-2013 IEPA nitrate nitrogen samples 1 out of 25 samples exceeded 10 mg/L CWLP data shows periodic exceedences in the nitrate drinking water standard
- 4. NUTRIENTS: THE BIG PICTURE Illinois contributes approximately 10-17% of the total phosphorus and nitrogen load to the Gulf of Mexico Lake Springfield loading 0.4% of the state’s nitrogen total 0.5% of the state’s phosphorus total Illinois Nutrient Loss Reduction Strategy calls for a 45% reduction in nitrogen and phosphorus loads.
- 5. WATERSHED OVERVIEW 169,161 acres Central Illinois Lake Springfield - Public water supply reservoir Impaired for nutrients (phosphorus) and sediment (TSS) Regularly exceeds state P standard of 0.05 mg/L Watershed Management Plan completed TMDL completed 93% reduction needed to meet P standard 54% reduction in sediment needed
- 6. • 7 subwatersheds The Lake Springfield Watershed
- 7. LAKE SPRINGFIELD WATERSHED IMPLEMENTATION PLAN A strategy and a work plan for achieving water resource goals A document that includes: A watershed description & characterization Estimates of pollution loading & load reductions Goals & targets Detailed actions & recommendations Responsible entities, cost estimates, milestones/schedule Education & outreach
- 8. • 74% cropland • 5% Forest • 4% Grassland • 3% Urban Residential Land Use
- 9. • 11% Highly Erodible Land (HEL) • 38% HEL soils being cropped HEL Soils
- 10. • Lack of adequate stream buffers or riparian zones • 51% of all open streams have less than 35ft of buffer Stream Buffers & Riparian Zones
- 11. TOTAL WATERSHED LOADING All Sources 2,318,168 lbs/yr Nitrogen 13.7 lbs/ac 213,402 lbs/yr Phosphorus 1.26 lbs/ac 164,901 tons/yr Sediment 0.97 tons/ac
- 12. SOURCES OF SEDIMENT & NUTRIENTS Nitrogen Crop runoff and tile flow Livestock Urban/Residential runoff Phosphorus & Sediment Crop runoff In-lake phosphorus release Streambank/Lake Bank erosion Urban/residential runoff Treated wastewater & septic
- 13. SOURCES OF SEDIMENT & NUTRIENTS Up to 5% of total lake P load from wastewater treatment plants Internal phosphorus release from lake sediment may be responsible for 30% of the in-lake P load (162 lbs/day) Cropped HEL soils 56% of all cropped HEL soils are conventionally tilled 35% of entire sediment load originating from crop ground is from 6,952 acres (6%) of cropped HEL soils
- 14. NONPOINT SOURCE POLLUTION LOAD MODEL Total Nitrogen Total Phosphorus Sediment
- 15. WATERSHED LOADING MODEL - SWAMM Spatially explicit GIS based nonpoint source model Shares characteristics with other models such as SWAT and pLoad except: Can evaluate loading at the field level Can evaluate the exact placement of treatment practices Can be visualized in map format It is relatively simple, relying on good input data for accurate outputs rather than complicated equations Easy to perform needed analysis Load allocation and load reductions ID critical loading zones
- 21. • Annual Nitrogen load – 2,281,826 lbs or 13.51 lbs/ac (98%) - 94% from crop ground (50% of this is tile flow) Nitrogen Loading Runoff
- 22. • Annual Phosphorus load – 194,762 lbs or 1.15 lbs/ac (91%) - 87% from crop ground Phosphorus Loading Runoff
- 23. • Annual sediment load – 153,892 tons or 0.92 tons/ac (93%) - 94% from crop ground Sediment Loading Runoff
- 24. • Possible on 109,083 ac • Annual Nitrogen reduction = 599,141 lbs • Annual Phosphorus reduction = 49,728 lbs • Annual Sediment reduction = 58,138 tons No-Till
- 25. • Possible on 14,052 ac • Annual Nitrogen reduction = 51,283 lbs • Annual Phosphorus reduction = 2,980 lbs • Annual Sediment reduction = 2,660 tons Cover Crops
- 26. • 324 ac possible (440,200ft) • Annual Nitrogen reduction = 54,298 lbs • Annual Phosphorus reduction = 9,279 lbs • Annual Sediment reduction = 9,651 tons Filter Strips
- 27. WEB-BASED WATERSHED MANAGEMENT SYSTEM Better collaborate and track progress toward meeting water quality goals Focus outreach to producers in the geographic areas where the resource concern exists Select the specific conservation practice that will best address the issue Accurately calculate both sediment and nutrient reductions that will result from implementation Assist in prioritizing practices based on their load reductions resulting in the greatest return on investment for each conservation dollar spent
- 28. WEB-BASED WATERSHED MANAGEMENT SYSTEM Key Components Secure Ability to navigate to the location of practices identified in the watershed plan an Ability to view, navigate, and query base map layers such as Ability to view and query sites experiencing the greatest potential soil and nutrient loss, calculate expected load reductions from proposed practices, and evaluate the effects of different practices A management dashboard with the ability to set numerical water quality targets and track progress Ability to add the status of a particular project and its attributes Ability to generate custom reports and quantify outcomes.
- 29. Interactive watershed management tool
- 32. View nitrogen, phosphorus, and sediment loading
- 33. View nitrogen, phosphorus, and sediment loading
- 34. Query nitrogen, phosphorus, and sediment loading
- 35. Navigate to Locations of Potential BMPs
- 36. Navigate to locations of potential BMPs and view information
- 37. Delineate custom areas, apply a BMP and calculate load reductions
- 38. Delineate custom areas, apply a BMP and calculate load reductions
- 39. Delineate custom areas, apply a BMP and calculate load reductions
- 41. QUESTIONS?