Sewer overflows in South Dakota
Sewer overflow record — reported spills, the worst utilities, and how often overflows reached waterways in South Dakota.
Reported events
177
Total volume
2.9B gal
Reached waterways
0(0%)
Latest event
Jun 25, 2026
Worst utilities in South Dakota
Ranked by number of reported overflow events.
Biggest spills in South Dakota
The largest single reported overflow events.
- 2.8B galMar 23, 2026Reached Moccasin Creek
- 7.8M galAug 14, 2025
- 4.9M galJun 21, 2024
- 4.7M galJun 20, 2024
- 3.9M galMar 22, 2024Reached Box Elder sewer system/POTW
- 2.9M galMar 4, 2024Reached Unnamed Tributary of Platte Creek
- 2.7M galMay 30, 2026Reached Big Sioux River
- 2.6M galJan 24, 2024Reached West branch of Lac Qui Parle River
- 2.5M galMay 20, 2025Reached Does not apply- Do not discharge to any waters
- 2.5M galJun 21, 2024