Upper Little Nemaha 26 Reservoir Report

Last Updated: December 5, 2025

Upper Little Nemaha 26 is a crucial flood risk reduction structure located in Lancaster, Nebraska, along the TR-Little Nemaha River.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1998, this earth dam stands at a height of 37 feet, with a hydraulic height of 36 feet and a structural height of 42 feet. With a storage capacity of 640 acre-feet and a drainage area of 2.5 square miles, this dam plays a vital role in mitigating flooding in the region.

Owned by the local government, Upper Little Nemaha 26 is regulated and inspected by the Nebraska Department of Natural Resources. The dam has a low hazard potential and was last inspected in 2016, with a satisfactory condition assessment. Its primary purpose is flood risk reduction, with a normal storage capacity of 93 acre-feet. Despite its age, the dam continues to effectively protect the surrounding area from potential flood events.

Located in Palmyra, Nebraska, Upper Little Nemaha 26 is situated in Congressional District 01, represented by Jeff Fortenberry. With its stone core and soil foundation, this dam is a crucial component of the flood management infrastructure in the region, safeguarding the community from potential water-related disasters.

Year Completed

1998

Dam Length

825

Dam Height

37

River Or Stream

TR-LITTLE NEMAHA RIVER

Primary Dam Type

Earth

Surface Area

16

Hydraulic Height

36

Drainage Area

2.5

Nid Storage

640

Structural Height

42

Hazard Potential

Low

Foundations

Soil

Nid Height

42
       
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.