Upper Big Nemaha L-10 Reservoir Report

Last Updated: December 5, 2025

Upper Big Nemaha L-10 is a local government-owned dam located in Lancaster, Nebraska, along the TR-N FK BIG NEMAHA RIVER.


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Summary

Built in 1968 by the USDA NRCS, this earth dam stands at a height of 22 feet and serves multiple purposes, including flood risk reduction. With a normal storage capacity of 28 acre-feet and a maximum discharge of 595 cubic feet per second, the dam plays a crucial role in managing water resources in the area.

Managed by the Nebraska Department of Natural Resources, Upper Big Nemaha L-10 has a low hazard potential and is currently in satisfactory condition. The dam is inspected every five years to ensure its structural integrity and safety. The surrounding area covers a drainage area of 0.5 square miles and a surface area of 7 acres. Despite its modest proportions, the dam provides essential protection against flooding and contributes to the overall water management efforts in the region.

Located in the city of Sterling, Nebraska, Upper Big Nemaha L-10 is a key component of the local water infrastructure. With its stone core and soil foundation, the dam has stood the test of time for over five decades. As climate change continues to impact water resources, this dam remains a vital asset for flood control and water conservation in the area, showcasing the importance of proactive management and maintenance of water infrastructure in the face of evolving environmental challenges.

Year Completed

1968

Dam Length

648

Dam Height

22

River Or Stream

TR-N FK BIG NEMAHA RIVER

Primary Dam Type

Earth

Surface Area

7

Hydraulic Height

21

Drainage Area

0.5

Nid Storage

103

Structural Height

27

Hazard Potential

Low

Foundations

Soil

Nid Height

27
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.