Upper Big Nemaha 18-B Reservoir Report
Last Updated: December 6, 2025
Upper Big Nemaha 18-B is a local government-owned dam located in Gage, Nebraska, designed by the USDA NRCS.
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Summary
Completed in 1980, this earth dam stands at a height of 48 feet, with a structural height of 53 feet and a length of 1410 feet. The dam serves the primary purpose of flood risk reduction along the TR-Hooker Creek, with a drainage area of 11.4 square miles and a storage capacity of 3768.7 acre-feet.
With a low hazard potential and a satisfactory condition assessment, Upper Big Nemaha 18-B offers reliable flood protection for the surrounding area. The dam is regulated by the Nebraska Department of Natural Resources, with state permitting, inspection, and enforcement in place to ensure its proper operation and maintenance. The last inspection in October 2020 found the dam to be in good condition, with an inspection frequency of every 5 years to assess its performance and safety.
As a crucial infrastructure for managing water resources in the region, Upper Big Nemaha 18-B plays a vital role in mitigating flood risks and protecting the local community from potential disasters. With its strategic location and design features, this earth dam serves as a key asset in the overall water resource and climate management efforts in Nebraska, showcasing the importance of effective dam infrastructure in safeguarding against natural hazards and promoting sustainable development.
Year Completed |
1980 |
Dam Length |
1410 |
Dam Height |
48 |
River Or Stream |
TR-HOOKER CREEK |
Primary Dam Type |
Earth |
Surface Area |
99 |
Hydraulic Height |
48 |
Drainage Area |
11.4 |
Nid Storage |
3768.7 |
Structural Height |
53 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
53 |
Seasonal Comparison
Weather Forecast
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 18-B