SCENARIO TOOL Lake Champlain Basin TMDL Lake Champlain Phosphorus - PowerPoint PPT Presentation

SCENARIO TOOL Lake Champlain Basin TMDL

Lake Champlain Phosphorus Water ershed ed In-lake ke ■ How is phosphorus loading distributed in watershed? ■ Monitoring data ■ Soil and Water Assessment: SWAT – In lake – USDA ARS and Texas A & M ■ Lake segments – Used to predict parameter fate and transport: – Water column ■ Climate – Sediment ■ Hydrology – In flows ■ Landscape characteristics and processes ■ River Basin (VT and NY) – Technical documentation 600+ pages

SWAT Output ■ 30 year time series of estimated P loading ■ Calibrated/Validated on empirical P data ■ Output at approximately HUC 12 scale

EPA Scenario Tool ■ Goal: BMP scenario that achieves TMDL based on SWAT loading estimates ■ Specifies which BMPs go on what land ‘type’ ■ Land ‘type’ = SWAT land use, slope class, and hydrologic soil group ■ Estimates P-loading rate, BMP efficiency, P-reduction, etc. ■ Described at BASIN scale ■ Exhaustive; in some cases, 100% of land ‘type’ requires BMP; in other cases, <100% BMP implementation is indicated

Example Scenario Tool Output 3. S Selec ect t 4. S Selec ect t 1. Se Select D Drain ainage Ar Area 2. S Selec ect t Land nduse Type HSG HSG Slo lope Ar Area ( a (ha) a) TP TP Load ( d (kg/yr yr) Corn-hay rotation on non- Mississquoi River clayey soils A All 1800.79 853.18 Mississquoi River Continuous hay B All 45.75 16.58 BMP P 6. E Enter TP L TP Load d Efficiency Appl pplied Reducti tion 5. Sel elect BMP T Type pe (%) Area ( Ar a (%) (kg/ g/yr yr) Cover Crop - Conservation Tillage - Grassed Waterways - Ditch Buffer - Riparian Buffer 0.89 1.00 763.03 Riparian Buffer 0.41 0.80 5.44

EPA Scenario Tool Application ■ Starting point for potential BMP placement ■ Modeled estimate of P-loading, potential reduction; consistent framework ■ Watershed Management Tool (WMT): Will provide map interface that will summarize loadings, potential reductions, and possible BMPs by township, NHD+ catchment, etc. *Still under discussion* ■ Inclusion of Tactical Basin Plan (TBP) implementation tables

EPA Scenario Tool Application: WMT COMID ID 234735 Drai ainag age A Area Lamoille River Landuse Continuous hay HSG SG D Slope All Total Ca Catchment A Area ( (ha) 5 Basin A Area ( (ha) 2590.65 Basin TP TP L Load ( (kg/yr) 2595.44 TP Rate k kg/ g/yr yr * *ha 1.00 BMP T Type ype Riparian Buffer BMP MP E Efficiency ( (%) 0.41 Basin T TP L Load R Reduction on ( (kg/y /yr) 851.30 Catchment T TP Load R Reduction on ( (kg/yr) 2.05