Rock Bass Allot 2 Dam Reservoir Report

Last Updated: December 6, 2025

Rock Bass Allot 2 Dam, located in Dawes County, Nebraska, serves multiple purposes including fire protection, stock watering, and small fish pond creation.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1936, this earth dam stands at a height of 14.5 feet and has a storage capacity of 84.1 acre-feet. Despite its low hazard potential, the dam's condition assessment is rated as poor, indicating a need for maintenance and repairs.

The dam, situated on Big Cottonwood Creek, falls under the jurisdiction of the Nebraska Department of Natural Resources and is subject to state regulation, permitting, inspection, and enforcement. Owned and operated by a federal agency, the Rock Bass Allot 2 Dam represents a critical infrastructure for managing water resources in the region. With a drainage area of 0.6 square miles and a maximum discharge of 500 cubic feet per second, the dam plays a vital role in controlling water flow and ensuring water availability for various uses.

Although the dam's condition is assessed as poor, its risk potential is considered low. However, given its importance in providing water resources for fire protection and livestock, efforts to improve the dam's condition and ensure its long-term reliability are essential. Climate and water resource enthusiasts can appreciate the role of Rock Bass Allot 2 Dam in managing water resources and its significance in the local ecosystem.

Year Completed

1936

Dam Length

490

Dam Height

14.5

River Or Stream

BIG COTTONWOOD CREEK

Primary Dam Type

Earth

Surface Area

11

Hydraulic Height

14.5

Drainage Area

0.6

Nid Storage

84.1

Structural Height

14.5

Hazard Potential

Low

Foundations

Soil

Nid Height

15
       
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.