Rock Creek (wasco)
Rock Creek (wasco) is an earth dam located in Wasco County, Oregon, built in 1947. It carries a High hazard potential classification and has a fair condition assessment.
About Rock Creek (wasco)
The primary purpose of Rock Creek (wasco) is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Rock Creek District Improvement Company (local government). It impounds the Rock, North Fork Gate, & Threemile near Tygh Valley.
The dam stands 51 feet tall and stretches 780 feet across, creates a reservoir covering 106 acres, has a maximum storage capacity of 1,500 acre-feet, and collects water from a drainage area of 10 square miles. Completed in 1947, the structure is well-established, with more than 75 years of service.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 10/20/2020.
At 51 feet, this dam is taller than 93% 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 Oregon 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 | Oregon |
| County | Wasco |
| Nearest City | Tygh Valley |
| River/Stream | Rock, North Fork Gate, & Threemile |
| Coordinates | 45.21916, -121.38361 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 51 ft |
| Dam Height | 51 ft |
| Dam Length | 780 ft |
| Year Completed | 1947 (79 years old) |
Storage & Hydraulics
| NID Storage | 1,500 acre-ft |
| Max Storage | 1,500 acre-ft |
| Normal Storage | 1,280 acre-ft |
| Surface Area | 106 acres |
| Drainage Area | 10 sq mi |
| Max Discharge | 904 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | ROCK CREEK DISTRICT IMPROVEMENT COMPANY |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 10/20/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OR00147 |
| Federal ID | OR00147 |
| More Info | State Dam Safety Program |