Roza Ww5 Reregulation Reservoir Reservoir Report
Nearby: Avalon Fruit Dam 3 Avalon Fruit Dam 4
Last Updated: December 15, 2025
Roza Ww5 Reregulation Reservoir, located in Sunnyside, Washington, is a vital public utility structure managed by the Washington Department of Ecology.
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Summary
Completed in 2017, this Earth type dam serves the primary purpose of irrigation, providing a storage capacity of 1600 acre-feet of water for agricultural needs in the Yakima County area. With a hydraulic height of 70 feet and a structural height of 70 feet, this reservoir covers a surface area of 31.2 acres and has a drainage area of 15.2 square miles.
The reservoir boasts a high hazard potential but has been assessed to be in satisfactory condition as of May 2017. Regular inspections occur every 5 years to ensure its safe operation. Although the spillway type, width, and other specific details are not provided, the dam is equipped to handle a maximum discharge of 125 cubic feet per second. With its location in Congressional District 04, this reservoir plays a crucial role in supporting agriculture in the region and is a key component in the water resource management of the area.
Roza Ww5 Reregulation Reservoir stands as a testament to the commitment of Washington state to effectively regulate and manage its water resources. With its significant storage capacity and strategic location in the Yakima Valley, this reservoir plays a vital role in supporting the irrigation needs of the agricultural community. As climate change continues to impact water availability, structures like Roza Ww5 Reregulation Reservoir are essential for ensuring a sustainable water supply for the future.
Year Completed |
2017 |
Dam Length |
5200 |
Primary Dam Type |
Earth |
Surface Area |
31.2 |
Hydraulic Height |
70 |
Drainage Area |
15.2 |
Nid Storage |
1600 |
Structural Height |
70 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
70 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Granger Drain At Granger
|
13cfs |
Yakima River At Mabton
|
19900cfs |
Columbia River Below Priest Rapids Dam
|
115000cfs |
Yakima River Above Ahtanum Creek At Union Gap
|
11300cfs |
Ahtanum Creek At Union Gap
|
164cfs |
Yakima River At Kiona
|
16300cfs |
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.
Roza Ww5 Reregulation Reservoir