The Cache Creek Settling Basin is located two miles east of Woodland, California and was constructed to preserve the floodway capacity of the Yolo Bypass by entrapping sediment. Cache Creek is the main source of mercury entering the San Francisco Bay-Delta. Entrapping sediment helps to entrap mercury thus acting to protect the aquatic life of the San Francisco Bay-Delta. A 2-dimensional hydraulic and sediment transport model is under development. The model modules for sediment transport and hydrodynamic modeling will be coupled under historical flow conditions. Preliminary results are presented herein. © 2010 ASCE.