Arthur R Bowman Dam


Arthur R. Bowman Dam (formerly Prineville Dam) is an earthfill structure on the Crooked River about 20 miles upstream from Prineville. The dam has a height of 240 feet, crest length of 790 feet, and a volume of 1,424,000 cubic yards of material.

The spillway consists of an uncontrolled-crest inlet structure, chute, and stilling basin. Capacity of the spillway is 8,120 cubic feet per second at maximum water surface elevation of 3,257.9 ft. The outlet works has an intake structure with an 11-foot-diameter circular tunnel upstream from the gate chamber, an 11-foot modified horseshoe tunnel downstream from the gate chamber, and a stilling basin which is shared with the spillway. The capacity of the outlet works is 3,300 cubic feet per second at normal water surface elevation of 3,234.8 ft.

The total capacity of Prineville Reservoir at closure was 154,690 acre-feet (active 152,800 acre-feet). A reservoir sedimentation survey completed in 1998 estimates the total capacity at 150,200 acre-feet (active 148,600 acre-feet).


The Crooked River drains a mountainous area composed of volcanic tuff and agglomerate beds, and basalt, rhyolite and andesite lava flows ranging in age from early Eocene to Recent.  The drainage basin exhibits a wide variety of topographic forms owing to variation in the resistance of volcanic beds and the varying degree of folding in the area.  Depth of overburden at the damsite is not uniform.  In the areas where bedrock exposures are common, overburden ranges from several feet deep.

RegionFacilities in Pacific Northwest | Pacific Northwest Home Page
ProjectCrooked River
Dam Type Zoned Earthfill
WatercourseCrooked River
Original Construction1958-1961
Modified Construction
National ID NumberOR00579
Hydrologic Unit Code

Structural Height240.0 ft
Hydraulic Height (Normal Operating Depth at Dam)182.0 ft
Top Parapet (Elevation)
Spillway Crest Elevation3234.8 ft
Crest Elevation3270.0 ft
Crest Length800.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis3076.0 ft
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)3234.8 ft
Top of Active Conservation Pool (Elevation)3234.8ft
Top of Inactive Conservation Pool (Elevation)3114.0 ft
Top of Dead Storage Pool (Elevation)3112.0 ft

Hydraulics & Hydrology
Total Water Storage at Elevation 152,800 ac-ft
Maximum Water Surface Elevation
Normal Water Surface Elevation3234.8 ft
Spillway Type Ungated overflow
Auxiliary SpillwayNo
Spillway Capacity at Elevation8,120 cfs at 3234.8 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation3300 cfs at 3234.8 ft
Diversion Capacity at Elevation
Drainage Area2635.0 sq mi
Hydrometeorological Report (HMR)HMR 57
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationColumbia-Cascades Area Office
Address1917 Marsh Road
CityYakima, WA 98901-2058
Phone (Fax)509 454-5611
Phone (Office)509 575-5848 x202
OrganizationOchoco Irrigation District
Address1001 North Deer St
CityPrineville, OR 97754-1134
Phone (Office)541 447-6449

Last updated: Oct 25, 2012