Upper Little Nemaha 23 Reservoir Report

Last Updated: December 5, 2025

Upper Little Nemaha 23 is a crucial piece of flood risk reduction infrastructure located in Lancaster, Nebraska.


°F

°F

mph

Wind

%

Humidity

Summary

Owned by the local government, this earth dam stands at a height of 51 feet and has a hydraulic height of 50 feet, providing protection to the surrounding area from potential flooding events. Completed in 2002, this dam has a storage capacity of 3,210-acre feet and serves a drainage area of 6.2 square miles along the TR-Little Nemaha River.

Managed by the Nebraska Department of Natural Resources, Upper Little Nemaha 23 is regularly inspected and maintained to ensure its structural integrity and functionality. With a significant hazard potential, it is crucial for the dam to undergo frequent assessments and adhere to safety guidelines to protect the community it serves. Despite its age, the dam's condition is deemed satisfactory, providing confidence in its ability to effectively mitigate flood risks in the region.

The dam's primary purpose is flood risk reduction, reflecting its vital role in safeguarding the area against potential water-related disasters. With its strategic location and reliable infrastructure, Upper Little Nemaha 23 stands as a testament to effective water resource management and climate resilience efforts in the region. For water resource and climate enthusiasts, this dam serves as a prime example of how proactive measures can help mitigate the impacts of extreme weather events on local communities.

Year Completed

2002

Dam Length

1735

Dam Height

51

River Or Stream

TR-LITTLE NEMAHA RIVER

Primary Dam Type

Earth

Surface Area

42

Hydraulic Height

50

Drainage Area

6.2

Nid Storage

3210

Structural Height

57

Hazard Potential

Significant

Foundations

Soil

Nid Height

57
       
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.