804 Reservoir Dam Reservoir Report
Last Updated: December 14, 2025
Located in Mesa, Washington, the 804 Reservoir Dam is a state-owned structure primarily used for irrigation purposes.
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Summary
Completed in 1979, this earthen dam stands at a hydraulic height of 12 feet and a structural height of 10 feet, with a length of 150 feet. It has a storage capacity of 160 acre-feet and covers a surface area of 10 acres, serving the surrounding area with water for agricultural needs.
Managed by the Washington Department of Ecology, the 804 Reservoir Dam is regulated, permitted, inspected, and enforced by the state. Its hazard potential is rated as low, and its condition assessment is currently not rated. The dam is situated offstream and falls under the jurisdiction of the Walla Walla District of the US Army Corps of Engineers. With a maximum discharge capacity of 50 cubic feet per second, this dam plays a crucial role in water resource management in the region.
Congressional District 04, represented by Dan Newhouse, oversees the 804 Reservoir Dam, ensuring its compliance with state regulations and safety standards. As a key infrastructure for irrigation in Franklin County, this dam underscores the importance of sustainable water resource management in the face of changing climate conditions. With its strategic location and vital role in supporting agricultural activities, the 804 Reservoir Dam stands as a testament to the resilience and adaptability of water infrastructure in the Pacific Northwest.
Year Completed |
1979 |
Dam Length |
150 |
River Or Stream |
Offstream |
Primary Dam Type |
Earth |
Surface Area |
10 |
Hydraulic Height |
12 |
Drainage Area |
0.2 |
Nid Storage |
160 |
Structural Height |
10 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
12 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Yakima River At Kiona
|
23800cfs |
Walla Walla River Near Touchet
|
1040cfs |
Columbia River Below Priest Rapids Dam
|
124000cfs |
Crab Creek Near Beverly
|
158cfs |
Palouse River At Hooper
|
1030cfs |
Crab Creek Near Moses Lake
|
28cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
804 Reservoir Dam