A Study of Underground Stormwater Detention Chambers and the Creation of the Model for Underground Detention of Sediment

This thesis investigates the hydraulic and runoff treatment capabilities of Underground Stormwater Detention Chambers (USDC) and compares them to stormwater management ponds, the industry standard system for runoff detention and treatment. Runoff characteristics were monitored at a USDC in Markham, Ontario. Characteristics include: total suspended solids, turbidity, nutrients, metals, bacteria, temperature, and hydrocarbons. The Model for Underground Detention of Sediment (MUDS) was created to predict the removal of suspended solids by a USDC. The results indicate that the Markham USDC meets all provincial hydraulic requirements and most water quality requirements. Also, the Markham USDC provides equivalent or improved level of service compared to stormwater management ponds for runoff treatment in most cases. MUDS was proven capable of accurately predicting USDC hydraulics and suspended solids removal for both event based and continuous based simulations.M.A.S