The U.S. Geological Survey (USGS), in cooperation with the City of Shawnee, performed a detailed bathymetric survey of Shawnee Reservoir in 2016. Shawnee Reservoir (locally known as Shawnee Twin Lakes) is a man-made reservoir on South Deer Creek in Pottawatomie County, Oklahoma. The reservoir consists of two lakes connected by an equilibrium channel. The southern lake (Shawnee City Lake Number 1) was impounded in 1935 and the northern lake (Shawnee City Lake Number 2) was impounded in 1960. Shawnee Reservoir has a normal pool elevation of 1,069.0 feet above North American Vertical Datum of 1988. The auxiliary spillway, which defines the flood pool, is at an elevation of 1,075.0 feet above North American Vertical Datum of 1988.