Sandstone Dam Reservoir Report
Nearby: Harrington Fairview Extension
Last Updated: December 5, 2025
Sandstone Dam, located on the Greybull River in Otto, Wyoming, is a gravity dam with a structural height of 28 feet and a hydraulic height of 24 feet.
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Summary
Completed in 2003 by the Bureau of Land Management, it serves a primary purpose of "Other" and has a storage capacity of 1231.19 acre-feet. The dam has a low hazard potential and an unsatisfactory condition assessment, with a moderate risk level.
Despite its relatively small size, Sandstone Dam plays a crucial role in water resource management in the Big Horn County area. Its uncontrolled spillway, with a width of 1 foot, allows for controlled release of water during periods of high flow, preventing flooding downstream. The dam's location on the Greybull River provides valuable water storage for irrigation, wildlife habitat, and recreational activities in the region.
With its unique design featuring buttress and stone core types, Sandstone Dam stands as a testament to the innovative engineering efforts of the Bureau of Land Management. Although it has not undergone recent inspections, the dam continues to serve the community while posing a moderate risk that necessitates ongoing risk management measures to ensure its safe operation for years to come.
Year Completed |
2003 |
Dam Length |
489 |
River Or Stream |
GREYBULL RIVER |
Primary Dam Type |
Gravity |
Surface Area |
66.65 |
Hydraulic Height |
24 |
Drainage Area |
0.15 |
Nid Storage |
1231.19 |
Structural Height |
28 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
28 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Bighorn River At Basin
|
996cfs |
Bighorn River At Kane
|
1340cfs |
Bighorn R At Worland Wyo
|
4350cfs |
Greybull River At Meeteetse
|
338cfs |
Shell Creek Near Shell
|
74cfs |
Shoshone River Near Lovell
|
460cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Sandstone Dam