scenario tool - ccrpc · 2016. 3. 10. · epa scenario tool goal: bmp scenario that achieves tmdl...
TRANSCRIPT
SCENARIO TOOL Lake Champlain Basin TMDL
Lake Champlain Phosphorus
■ Monitoring data – In lake
■ Lake segments – Water column – Sediment
– In flows ■ River Basin (VT and NY)
■ How is phosphorus loading distributed in watershed?
■ Soil and Water Assessment: SWAT – USDA ARS and Texas A & M – Used to predict parameter fate and transport:
■ Climate ■ Hydrology ■ Landscape characteristics and processes
– Technical documentation 600+ pages
In-lake Watershed
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
1. Select Drainage Area 2. Select Landuse Type 3. Select HSG
4. Select Slope Area (ha) TP Load (kg/yr)
Mississquoi River Corn-hay rotation on non-clayey soils A All 1800.79 853.18
Mississquoi River Continuous hay B All 45.75 16.58
5. Select BMP Type
BMP Efficiency (%)
6. Enter Applied Area (%)
TP Load Reduction (kg/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 234735 Drainage Area Lamoille River Landuse Continuous hay HSG D Slope All Total Catchment Area (ha) 5 Basin Area (ha) 2590.65 Basin TP Load (kg/yr) 2595.44 TP Rate kg/yr *ha 1.00 BMP Type Riparian Buffer BMP Efficiency (%) 0.41 Basin TP Load Reduction (kg/yr) 851.30 Catchment TP Load Reduction (kg/yr) 2.05