Stormwater Management Pond # PD03-02 Sediment Management

completed

This project will remove and dispose of 2,600 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 had been 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, resulting in untreated water being released to the Creek. The Town of Whitby conducted a ponds need study in 2011 to evaluate the pond permanent storage capacity. A bathymetric survey revealed that a fair amount of sediment had accumulated in the ponds and a majority of the ponds require cleanout. Under this project accumulated sediment in the pond will be removed allowing for the required permanent storage in the pond. The resulting pond will perform to its design 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.