Stormwater Management Pond #PD47-01 Sediment Management

completed

This project will remove and dispose of 500 m3 of sediment from the pond. The project includes cleaning of outlets and restoration of the disturbed area. The majority of the Town’s storm water ponds were constructed with permanent storage volume (wet ponds). The purpose of the permanent storage volume in a pond is to allow suspended solids (sediment) from the runoff to settle down in the pond bottom and release the treated water to the creek. Over time, the pond will accumulate sediment which will reduce the permanent storage, impacting the sediment removal efficiency of the pond drastically and resulting in untreated water being released to the Creek. Realising a need for a pond clean out, the Town of Whitby conducted a pond needs study in 2011 to evaluate the pond permanent storage capacity. The study showed that the majority of the ponds require cleanout as bathymetric survey revealed a fair amount of sediment accumulation in the ponds. Under this project accumulated sediment in the pond will be removed, allowing required permanent storage in the pond. The resulting pond will perform to its designed efficiency which will improve the quality of the runoff released to the creeks. The removal works are capitalized as they extend the life of the asset.