Evaluation of Design Criteria for Construction Sediment Control Ponds – Markham, Ontario
In 2004, comprehensive monitoring of suspended sediment and hydrologic parameters was initiated on an ‘enhanced level’ construction sediment pond in Markham, Ontario. This program included continuous flow measurements, discrete sediment sampling, particle size analysis and bathymetric surveys of the pond to determine the rate and distribution of sediment accumulation in the pond during the construction period. Monitoring was completed in 2005.
Monitoring data was used to set-up and calibrate a hydrodynamic model that simulated long-term performance of the pond and evaluated various alternative pond design scenarios. These scenarios provided insights into the potential impacts on pond performance of changes in sediment accumulation rates (i.e. reductions in permanent pool storage), drawdown time, length-to-width ratio, extended detention storage, particle size and other design parameters or catchment attributes. Monitoring and modeling results were subsequently used to provide recommendations on the appropriate configuration of temporary construction sediment ponds for the protection of aquatic habitat and receiving water quality downstream of the facility, and have since been incorporated into the Greater Golden Horshoe Conservation Authorities Erosion and Sediment Control Guideline for Urban Construction.
For more detailed results on this study, see the report entitled Evaluation of Design Criteria for Construction Sediment Control Ponds – Markham, Ontario