Sunnyside Mp 23.7 Reservoir Reservoir Report
Last Updated: December 14, 2025
Sunnyside Mp 23.7 Reservoir, nestled in Granger, Washington, is a vital water resource managed by a public utility with oversight from the Washington Department of Ecology.
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Summary
Completed in 2008, this offstream dam on the Yakima River serves primarily for irrigation purposes, boasting a capacity of 604 acre-feet and a surface area of 24 acres. The reservoir's hydraulic height stands at 43 feet, with a structural height of 37 feet, ensuring a steady supply of water for the surrounding agricultural lands.
With a high hazard potential but a satisfactory condition assessment as of May 2018, Sunnyside Mp 23.7 Reservoir is a key component of the local water infrastructure. The dam's design by CH2M Hill incorporates earth and rockfill core types, providing stability and reliability for its operations. In times of emergency, the reservoir's Emergency Action Plan is in place to guide response efforts, with regular inspections conducted to ensure the structure's integrity. Despite its small drainage area of 0.04 square miles, the reservoir plays a critical role in water management in the region.
Located within Congressional District 04, Washington, Sunnyside Mp 23.7 Reservoir underscores the importance of sustainable water resource management in the face of climate change. As climate enthusiasts and water resource advocates, understanding the functionality and regulatory oversight of such infrastructure is crucial for ensuring the long-term resilience of water systems in the Yakima Valley. The reservoir's presence not only supports local agriculture but also highlights the ongoing efforts to balance water needs, environmental concerns, and community safety in the region.
Year Completed |
2008 |
Dam Length |
9000 |
River Or Stream |
Yakima River - Offstream |
Primary Dam Type |
Earth |
Surface Area |
24 |
Hydraulic Height |
43 |
Drainage Area |
0.04 |
Nid Storage |
604 |
Structural Height |
37 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
43 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Granger Drain At Granger
|
13cfs |
Yakima River At Mabton
|
28900cfs |
Yakima River Above Ahtanum Creek At Union Gap
|
14200cfs |
Ahtanum Creek At Union Gap
|
197cfs |
Columbia River Below Priest Rapids Dam
|
124000cfs |
Toppenish Creek Near Fort Simcoe
|
57cfs |
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.
Sunnyside Mp 23.7 Reservoir