Storage from official US gauges (USGS, USACE, Bureau of Reclamation, CDEC). Fill % uses design capacity from the National Inventory of Dams where available; a few sites without a match fall back to the 5-year maximum.

About reservoirs in South Dakota

As of July 30, 2026, the reservoirs we track across South Dakota that report live levels hold roughly 26,509 hm³ of water — about 81.6% of their combined capacity. Taken together, South Dakota's reservoirs are high.

Across the region, 1 is low. Big Bend Dam & Reservoir is the fullest at 97.1%, while Shadehill Dam & Reservoir is the lowest at 32.7%.

Storage figures for South Dakota come from USGS · USACE · BOR · CDEC; the most recent reading is from July 30, 2026. Each reservoir below links to its own page with full history and seasonal context.

South Dakota at a glance

Reservoirs tracked: 14
Average fill: 81.6%
Water stored: 26,509 hm³
Combined capacity: 32,483 hm³
Fullest: Big Bend Dam & Reservoir (97.1%)
Lowest: Shadehill Dam & Reservoir (32.7%)
Last updated: July 30, 2026

Frequently asked questions

How full are reservoirs in South Dakota right now?

As of July 30, 2026, the reservoirs tracked in South Dakota that report live levels are 81.6% full overall, holding about 26,509 hm³ of water.

How many reservoirs are there in South Dakota?

reservoirs.earth tracks 14 reservoirs in South Dakota, with a combined storage capacity of 32,483 hm³.

Which reservoir in South Dakota is the fullest?

Big Bend Dam & Reservoir is currently the fullest reservoir in South Dakota, at 97.1% of capacity.

Which reservoir in South Dakota is the lowest?

Shadehill Dam & Reservoir is currently the lowest in South Dakota, at 32.7% of capacity.

Where does the reservoir data for South Dakota come from?

All storage figures for South Dakota come from USGS · USACE · BOR · CDEC, an official source, last updated July 30, 2026.

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