New Tools for Assessing the Effectiveness of Field-Scale Best Management Practices
Ross Wilson and Mari VelizAusable Bayfield Conservation Authority
Soil and Water Conservation Society2014 Annual Conference
July 29 2014
WASCoBs
Water And Sediment Control Basins
WASCoBs
Water Quantity
Storage = Inflow - Outflow
Inflow = Outflow + Storage
Storage = Inflow - Outflow
Inflow = Outflow + Storage
GIS3D AnalystSurvey or DEM
32mm
15mm
41mm
5mm
BASIN storage (mm of runoff)
Storage = Inflow - Outflow
Inflow = Outflow + Storage
EFFECTIVENESS
• 90% peak flow reduction• 1 hr inflow• 10hr outflow
14:00 16:00 18:00 20:00 22:00 00:0015Mar2012
L/s
0
50
100
150
200
WASCoB INFLOW vs OUTFLOW
INFLOW VERMUE BERM BAYFIELD OUTFLOW VERMUE BERM BAYFIELD
WASCoBs
Water Quality
WASCoBsWater Quality
Effectiveness = difference between inflow and outflow
CHALLENGES !!
CHALLENGES !!Inflow sampler
2013
CHALLENGES !!Outflow sampler
Basin INFLOW- Sequential water sampler- stage and inflow
Basin OUTFLOW- ISCO automatic water sampler- stage and outflow
CHALLENGES !!
RESULTS
2013 Median values Inflow Outflow % reduction
Total Suspended Solids (mg/L) 2680.0 1145.0 57 %
Total Phosphorus (mg/L) 1.890 1.120 41 %
Soluble Reactive Phosphorus (mg/L) 0.262 0.178 32 %
Total Kjeldahl Nitrogen (mg/L) 1.85 0.88 52 %
Nitrate (mg/L) 1.03 1.66 27 to ‐61 %
