Thief Valley Dam

Thief Valley Dam is a buttress dam located in Union County, Oregon, built in 1932. It carries a High hazard potential classification.

Hazard potentialHighFailure would probably cost lives
ConditionNot assessed
Emergency action planOn file
Last inspection08/29/2023
Height73 ft
Built193294 years ago

Dam profile

NID height · 73 ft
73 FT TEN-STORY BUILDINGMEDIAN U.S. DAM · 24 FT

73 ft tall and 390 ft long, taller than 96% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic concrete gravity section and the water level is illustrative.

About Thief Valley Dam

The primary purpose of Thief Valley Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bureau of Reclamation (federal). It impounds the Powder River near Keating.

The dam stands 73 feet tall and stretches 390 feet across, creates a reservoir covering 807 acres, has a maximum storage capacity of 13,307 acre-feet, and collects water from a drainage area of 914 square miles. Completed in 1932, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 08/29/2023.

At 73 feet, this dam is taller than 96% of all dams in the United States.

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

StateOregon
CountyUnion
Nearest CityKeating
River/StreamPowder River
Coordinates45.01270, -117.78100

Physical Characteristics

Dam TypeButtress
NID Height73 ft
Dam Height66 ft
Dam Length390 ft
Year Completed1932 (94 years old)

Storage & Hydraulics

NID Storage13,307 acre-ft
Max Storage13,307 acre-ft
Surface Area807 acres
Drainage Area914 sq mi
Max Discharge32,200 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeIrrigation
OwnerBureau of Reclamation
Owner TypeFederal
Hazard ClassificationHigh
Condition AssessmentNot assessed
Last Inspection08/29/2023
Emergency Action PlanYes

Identifiers

NID IDOR00592
Federal IDOR00592
More InfoState Dam Safety Program