Upper Big Nemaha 27-R Reservoir Report
Last Updated: February 22, 2026
Upper Big Nemaha 27-R is a flood risk reduction dam located in Gage, Nebraska, along Shaw Creek.
Summary
Constructed in 1986 by the USDA NRCS, this earth dam stands at a height of 30 feet with a hydraulic height of 27 feet, providing essential flood protection for the surrounding area. With a drainage area of 4.3 square miles, the dam has a storage capacity of 1378 acre-feet and a normal storage level of 279 acre-feet, helping to mitigate potential flood hazards in the region.
Managed by the Nebraska Department of Natural Resources, Upper Big Nemaha 27-R is subject to state regulation, inspection, and enforcement to ensure its structural integrity and operational effectiveness. The dam's condition assessment in 2019 deemed it satisfactory, with a significant hazard potential due to its location and purpose. With a length of 895 feet and a surface area of 60 acres, this crucial water resource infrastructure plays a vital role in protecting the local community from the impacts of flooding, highlighting the importance of effective dam management and maintenance in the face of changing climate conditions.
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15-Day Weather Outlook
Year Completed |
1986 |
Dam Length |
895 |
Dam Height |
30 |
River Or Stream |
SHAW CREEK |
Primary Dam Type |
Earth |
Surface Area |
60 |
Hydraulic Height |
27 |
Drainage Area |
4.3 |
Nid Storage |
1378 |
Structural Height |
32 |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
32 |
Seasonal Comparison
5-Day Hourly Forecast Detail
Nearby Streamflow Levels
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.
Upper Big Nemaha 27-R