Sioux Falls

Sioux Falls. This is the location of the historical Big Sioux River channel. This area, like many along the Big Sioux River's banks were very susceptible to seasonal flooding - predominantly caused by snowmelt runoff and by rainfall., To improve the City's flood resilience, a $48.5 million (2019 dollars) flood control system, completed in 1965, was constructed along the Big Sioux River and its tributaries. This system included a levee system and a diversion channel with a dam at one end and a spillway at the other. The river channel was also widened and straightened. The system diverts flood waters past the City to reduce flood damages. Since the upgraded flood control system has been in place, over $30.5 million (2019 dollars) have been reinvested to increase the system's carrying capacity., As the City's size and population grows, flood risks remain and are continually evaluated and system improvements and efficiencies are needed., Residents should be aware of their personal flood risk. Here, the Base Flood Elevation for a 1% annual chance flood event (regulated floodplain) is approximately 10 feet above ground level., (See the marker above.), Historical Marker , Learn more about South Dakota's flood history at history.sd.gov/archives., caption: , Since 1950, the Big Sioux River flooded in 1951, 1952, 1957, 1960, 1962, 1969, 1983, 1984, 1990, 2018, and 2019. Looking east on June 17, 1957, the Big Sioux River floods the meat packing plant at North Weber Avenue and East Rice Street. , Photo Courtesy: Siouxland Heritage Museums, Sioux Falls, S.D., Silver Jackets brings together federal, state, and local agencies to collaborate in reducing flood risk. Prepare your family at bReady.sd.gov..