Prosser Warehouse Treatment Lagoon Reservoir Report
Last Updated: December 15, 2025
Prosser Warehouse Treatment Lagoon, located in Prosser, Washington, is a privately owned water treatment facility regulated by the Washington Department of Ecology.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 2012, this Earth-type dam stands at a hydraulic height of 12 feet and has a storage capacity of 17 acre-feet, with a normal storage level of 13.8 acre-feet. Despite its significant hazard potential, the dam's condition assessment in 2018 deemed it satisfactory, ensuring the safety and efficiency of its operations.
The lagoon serves a primary purpose of water resource management, providing crucial treatment and storage capacity for the surrounding area. It undergoes regular inspections, with a frequency of every 5 years, to maintain its structural integrity and prevent any potential risks. The facility's emergency action plan was last revised in 2019, demonstrating a commitment to preparedness and ensuring that the necessary measures are in place to address any unforeseen situations effectively.
With its strategic location in Benton County and proximity to Congressional District 04, the Prosser Warehouse Treatment Lagoon plays a vital role in environmental protection and sustainable water management practices. As a key asset in the region, it exemplifies the importance of regulatory oversight and proactive maintenance to safeguard water resources and address the challenges posed by climate change.
Year Completed |
2012 |
Primary Dam Type |
Earth |
Hydraulic Height |
12 |
Nid Storage |
17 |
Structural Height |
12 |
Hazard Potential |
Significant |
Nid Height |
12 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Yakima River At Kiona
|
23800cfs |
Yakima River At Mabton
|
28900cfs |
Granger Drain At Granger
|
13cfs |
Columbia River Below Priest Rapids Dam
|
124000cfs |
Umatilla River Near Umatilla
|
516cfs |
Yakima River Above Ahtanum Creek At Union Gap
|
14200cfs |
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.
Prosser Warehouse Treatment Lagoon