Sasse Reservoir Dam Reservoir Report

Last Updated: December 13, 2025

Sasse Reservoir Dam, located in Okanogan, Washington, was completed in 1910 with a primary purpose of recreation.


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Summary

The dam is owned by the state and regulated by the Washington Department of Ecology. With a low hazard potential and a structural height of 8 feet, the dam holds a storage capacity of 60 acre-feet on the Tr-Okanogan River.

The earth dam, constructed with stone core types and soil foundations, has a hydraulic height of 10 feet and a length of 140 feet. The reservoir covers a surface area of 3 acres and has a drainage area of 3.82 square miles. While the dam is not currently rated for its condition, it meets all necessary state regulations for inspection and enforcement.

Sasse Reservoir Dam provides a valuable recreational resource for the surrounding area while also serving as a critical water management structure. Its low hazard potential and state jurisdiction ensure the safety and integrity of the dam, making it a vital asset for water resource and climate enthusiasts in Washington.

Year Completed

1910

Dam Length

140

River Or Stream

Tr-Okanogan River

Primary Dam Type

Earth

Surface Area

3

Hydraulic Height

10

Drainage Area

3.82

Nid Storage

60

Structural Height

8

Hazard Potential

Low

Foundations

Soil

Nid Height

10
       
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.