Pactola Reservoir
Pactola Reservoir is managed by U.S. Bureau of Reclamation. Lake Insights displays its latest available elevation from USACE NWO District.
Lake Status
- 7-day trend
- Falling
- 7-day change
- Down 0.25 ft
- 30-day change
- Down 0.25 ft
- Last updated
- 2 hours ago
Watershed drought conditions
Pennington County, SD · surrounding county from lake location
Severe Drought
Severe drought conditions are present.
Severity
Weekly trend
Stable
Compared with last week
Official drought
Yes
98.9% of the watershed is currently classified as official drought (D1+).
Expected impacts
- Lower stream inflows
- Lake levels may decline faster
- Vegetation is becoming drier
- Minor increase in wildfire risk
U.S. Drought Monitor · map date Sep 8, 2026. Updated weekly. droughtmonitor.unl.eduView drought map for Pennington County, SD
Key Facts
Managing authority
Waterbody / project type
Official purposes
Current-level source
Project / NID identifier
Dam / watershed (NID design values)
Static design values from a confidently matched National Inventory of Dams record — not live gage readings.
- Normal storage
- 55,965 acre-ft
- Max storage
- 140,898 acre-ft
- Surface area at normal pool
- 1,557 acres
- Drainage area
- 320 sq mi
- Spillway capacity (design)
- 245,000 cfs
- Dam structure
- Earth · 245 ft high · completed 1956
- Hazard classification
- High
- Safety & inspection
- last inspection May 4, 2023
National Inventory of Dams · matched record: Pactola Dam (SD01139)
How this lake is operated
- Documented project purposes (National Inventory of Dams): Flood Risk Reduction, Irrigation, Recreation, Water Supply.
Why the level can change
General factors for reservoirs like this
These are common influences for this type of lake. They do not identify the cause of a specific current change unless an operator update confirms it.
Rainfall & inflows
Rain and upstream river inflows can raise reservoir levels, especially after storms.
Downstream releases
When an operator releases water through a dam, reservoir storage can fall and downstream flows can rise.
Flood-risk operations
Some projects store or release water under flood-risk rules when conditions require it.
Water supply
Some reservoirs support municipal, industrial, irrigation, or regional water-supply needs.
Hydropower
Hydropower projects may pass water through turbines when generating electricity.
Seasonal weather
Dry periods, heat, evaporation, and seasonal rainfall patterns can affect storage over weeks and months.
Current data source
Managing authority: U.S. Bureau of Reclamation
Observation source used by Lake Insights: USACE NWO District
Who manages the lake and who publishes the reading Lake Insights displays can differ. Lake Insights does not invent a source label from the managing authority alone.
General education
Shared background — not lake-specific facts
Lake Insights aggregates water level information from authoritative public sources such as the U.S. Army Corps of Engineers, NOAA, TVA, Bureau of Reclamation, power utilities, and other official lake operators. We preserve historical observations, calculate trends, and present lake conditions in a consistent format. For USACE NWO District, we link to the official source whenever it is available. Lake Insights does not predict future lake levels unless an official forecast has been published by the managing authority.
Common questions about Pactola Reservoir
- Who manages Pactola Reservoir?
- Pactola Reservoir is managed by U.S. Bureau of Reclamation. Lake Insights reports published gauge readings; it does not operate the waterbody.
- Where does Lake Insights get the level reading for Pactola Reservoir?
- Lake Insights displays the latest available elevation for Pactola Reservoir from USACE NWO District. The managing authority (U.S. Bureau of Reclamation) may differ from the agency that publishes the observation used on this page.
- What are the documented purposes of Pactola Reservoir?
- Documented purposes for Pactola Reservoir (National Inventory of Dams): Flood Risk Reduction, Irrigation, Recreation, Water Supply.