Big Sioux River

Big Sioux River tributary floodwaters wash through cattle yards in the upper reaches of the river basin on April 13, 2023. (Brad Johnson/For South Dakota Searchlight)

Pollution carried by major floods is killing our lakes

BY: - April 20, 2023

The state of South Dakota’s lackadaisical, careless approach to protecting its lakes and streams from agricultural pollution is glaringly apparent when floods are viewed from an airplane.  Hundreds of acres of plowed fields sent tons of black soil down the Big Sioux River during the week of April 8-15. Significant amounts of mud ended up […]

The Big Sioux River under Watertown's stone bridge on Kemp Avenue in winter (J.T. Fey/For South Dakota Searchlight)

Ongoing study shows Big Sioux River mixing with aquifer that Watertown uses for water

BY: - February 20, 2023

The waters of the Big Sioux River are infiltrating the drinking water pulled from wells near Watertown, causing potentially harmful effects that aren’t fully understood yet. Those early conclusions come from a joint state and U.S. Geological Survey study on interactions between the river and the Big Sioux Aquifer. The study does not offer conclusions […]

Water quality group gives Big Sioux River an ‘F’ grade over E. coli contamination

BY: - November 15, 2022

A water conservation non-profit gives the Big Sioux River an ‘F’ grade over E. coli levels beyond what’s considered safe by the state Department of Agriculture and Natural Resources (DANR). Nitrate levels in the river, fueled in part by agricultural fertilizer runoff, are also rising. The report card was presented Monday evening at Augustana University […]