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 %

Questions ?

rwilson@abca.on.cawww.abca.on.ca

519-235-2610