The Riverbed Gradient Facility, Sacramento California. Over 180,000 cubic yards of cementitious river rock was excavated. Approximately 240,000 tons of riprap was placed between a series of sheetpile walls which formed the cells to create the gradient structure. The primary focus of this project was to create a 1,500 x 750 foot structure to protect migrating salmon from nearby intake pumps used by a local irrigation district.