Hydrodynamic and Sediment Transport Study of Sudbury River, Massachusetts

Abstract : Numerical models were used to determine the transport potential for contaminated sediments in two reaches of the Sudbury River near Framingham, Massachusetts. These two reaches are comprised of two small (narrow) reservoirs, one discharging into the other. They are essentially riverine in nature at flows characteristic of this study. A computational hydrodynamic model (RMA2) of the reaches was developed. Several known worst case flood conditions were simulated and the model verified. A sediment transport model (SED2D) was then run using the hydrodynamic responses as the driving force to erode, transport, and deposit sediments. The results of the simulation indicate a potential movement of contaminated sediments in the constricted and shallow areas of the reservoirs for the Standard Project Flood (SPF) conditions. For the lower flow test conditions, 3-year, 14-year, and 100-year flood frequencies, the numerical model computer simulations predicted movement of only negligible amounts of contaminated sediments. Only at the highest flow conditions (SPF) was the movement of sediment considered significant.