Sunnyside Mp 23.7 Reservoir
Sunnyside Mp 23.7 Reservoir is an earth dam located in Yakima County, Washington, built in 2008. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Sunnyside Mp 23.7 Reservoir
The primary purpose of Sunnyside Mp 23.7 Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Sunnyside Valley Irrigation Dist. (public utility). It impounds the Yakima River - Offstream near Granger.
The dam stands 43 feet tall and stretches 900 feet across, creates a reservoir covering 24 acres, has a maximum storage capacity of 604 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 2008, the structure is relatively new.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 09/28/2023.
At 43 feet, this dam is taller than 89% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Washington dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Washington |
| County | Yakima |
| Nearest City | Granger |
| River/Stream | Yakima River - Offstream |
| Coordinates | 46.38082, -120.17749 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 43 ft |
| Dam Length | 900 ft |
| Year Completed | 2008 (18 years old) |
Storage & Hydraulics
| NID Storage | 604 acre-ft |
| Max Storage | 604 acre-ft |
| Normal Storage | 504 acre-ft |
| Surface Area | 24 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 2,000 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Sunnyside Valley Irrigation Dist. |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/28/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00709 |
| Federal ID | WA00709 |
| More Info | State Dam Safety Program |