Longley Dam Reservoir Report
Nearby: Knapple Dam Jk Land Dam
Last Updated: December 13, 2025
Longley Dam in Nebraska, completed in 1946, is a privately owned structure with a primary purpose of flood risk reduction.
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Summary
This earth dam stands at a height of 10.6 feet and has a storage capacity of 65.6 acre-feet, providing crucial protection to the surrounding area. Located in Dawson County, near the city of Overton, Longley Dam spans 180 feet in length and covers a surface area of 6.14 acres. It is regulated by the Nebraska Department of Natural Resources and undergoes regular inspections to ensure its structural integrity.
The dam's low hazard potential and "Not Rated" condition assessment indicate its stable and safe status. With a drainage area of 0.92 square miles and a maximum discharge of 1245 cubic feet per second, Longley Dam plays a crucial role in managing water resources and protecting the local community from potential flooding events. Its strategic location along Crooked Creek underscores its significance in maintaining the region's water infrastructure and climate resilience efforts. Enthusiasts of water resources and climate management will appreciate Longley Dam's vital contribution to safeguarding the area against natural disasters and maintaining a sustainable water supply.
Year Completed |
1946 |
Dam Length |
180 |
Dam Height |
10.6 |
River Or Stream |
TR-CROOKED CREEK |
Primary Dam Type |
Earth |
Surface Area |
6.14 |
Hydraulic Height |
10.6 |
Drainage Area |
0.92 |
Nid Storage |
65.6 |
Structural Height |
10.6 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
11 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Spring Creek Nr Overton
|
7cfs |
Buffalo Creek Nr Overton Nebr
|
3cfs |
Platte River Near Overton
|
1390cfs |
Elm Creek Nr Elm Creek
|
0cfs |
Platte R Mid Ch
|
1280cfs |
Platte River Near Kearney
|
928cfs |
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.
Longley Dam