Map of All 2,549 South Dakota Dams
South Dakota has 2,549 dams in the National Inventory of Dams — and 93 are classified as high hazard (4% of the state’s total), meaning failure would likely cause loss of life. 23 South Dakota dams are both high-hazard and in poor or unsatisfactory condition.
Use the interactive South Dakota dams map below to explore every dam in the state, color-coded by hazard level. Click any dam for its condition assessment, last inspection date, and Emergency Action Plan status. Or view the full US Dams interactive map to compare South Dakota to every other state.
Hazard
Condition
Purpose
South Dakota Dams by the Numbers
- 2,549 total dams in South Dakota
- 93 high hazard — failure would likely cause loss of life
- 149 significant hazard
- 2,307 low hazard
- 34 in poor or unsatisfactory condition (25 poor, 9 unsatisfactory)
- 23 South Dakota dams are both high-hazard AND in poor/unsatisfactory condition
Data source: US Army Corps of Engineers, National Inventory of Dams (NID).
The Tallest Dams in South Dakota
The tallest dam in South Dakota is Grizzly Gulch Tailings Dam at 380 feet, completed in 1998. The 10 tallest South Dakota dams from the National Inventory of Dams:
| Dam | Height | Year | Primary Purpose | Condition | County |
|---|---|---|---|---|---|
| Grizzly Gulch Tailings Dam | 380 ft | 1998 | Tailings | Satisfactory | Lawrence |
| Pactola Dam | 245 ft | 1956 | Flood Risk Reduction | Not Available | Pennington |
| Oahe Dam – Fort Yates Flood Protection Project | 245 ft | 1966 | Flood Risk Reduction | Not Available | Sioux |
| Oahe Dam | 245 ft | 1966 | Flood Risk Reduction | Not Available | Stanley |
| Big Bend Dam | 205 ft | 1963 | Flood Risk Reduction | Not Available | Lyman |
| Angostura Dam | 193 ft | 1949 | Irrigation | Not Available | Fall River |
| Deerfield Dam | 171 ft | 1947 | Fish and Wildlife Pond | Not Available | Pennington |
| Fort Randall Dam | 170 ft | 1954 | Flood Risk Reduction | Not Available | Charles Mix |
| Pactola Dike 2 | 150 ft | 1956 | Flood Risk Reduction | Not Available | Pennington |
| Shadehill Dam | 145 ft | 1951 | Flood Risk Reduction | Not Available | Perkins |
High-Hazard South Dakota Dams in Poor Condition
The most concerning dams are those classified as high-hazard that also carry a Poor or Unsatisfactory condition rating — 23 dams in South Dakota. Notable examples:
- Oglala (62 ft, Oglala Lakota County) — Recreation, Unsatisfactory condition
- Marindahl (58 ft, Yankton County) — Recreation, Poor condition
- Richmond (52 ft, Brown County) — Recreation, Poor condition
- Ghost Hawk (47 ft, Todd County) — Recreation, Unsatisfactory condition
- Rank Dam (40 ft, Buffalo County) — Recreation, Poor condition
Filter the interactive US Dams map by hazard and condition to see all of them on one view.
Dam Safety in South Dakota
Dam safety in South Dakota is overseen by the state dam safety program, in coordination with federal regulators: the US Army Corps of Engineers, the Bureau of Reclamation (for federal water projects), the Tennessee Valley Authority where applicable, and the Federal Energy Regulatory Commission (FERC) for licensed hydropower dams. Emergency Action Plans are typically required for high-hazard dams under state regulations.
Frequently Asked Questions
How many dams are in South Dakota?
South Dakota has 2,549 dams in the National Inventory of Dams tracked by the US Army Corps of Engineers: 93 high hazard, 149 significant hazard, and 2,307 low hazard.
What is the tallest dam in South Dakota?
The tallest dam in South Dakota is Grizzly Gulch Tailings Dam at 380 feet, completed in 1998. It is primarily a tailings structure.
How many South Dakota dams are in poor condition?
34 South Dakota dams are currently rated as being in Poor or Unsatisfactory condition. Of those, 23 are also classified as high-hazard — meaning failure would likely cause loss of life.
