Foss Dam

The dam site foundation consists of sandy and silty clay overburden underlain by essentially horizontally bedded sandstones, shales and gypsum of the Cloud Chief formation.  Overburden materials vary from 15 to 20 feet on the left abutment and from 0 to 6 feet on the right abutment.  In the old or buried river channel, the depth to bedrock is about 125 feet.  The upper 70 feet of overburden is composed of silty and sandy clay, while the remaining 55 feet is sand and gravel.  Beneath the gravel, bedrock consists of a 15-foot bed of silty sandstone underlain by seven feet of gypsum.

RegionFacilities in Great Plains | Great Plains Home Page
ProjectWashita basin
Dam Type
WatercourseWashita River
Original Construction1958-1961
Modified Construction
National ID NumberOK02503
Hydrologic Unit Code

Structural Height142.0 ft
Hydraulic Height (Normal Operating Depth at Dam)105.6 ft
Top Parapet (Elevation)
Spillway Crest Elevation1668.6 ft
Crest Elevation1697.0 ft
Crest Length18130.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis1563.0 ft
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)1642.0 ft
Top of Inactive Conservation Pool (Elevation)
Top of Dead Storage Pool (Elevation)1597.2 ft

Hydraulics & Hydrology
Total Water Storage at Elevation
Maximum Water Surface Elevation
Normal Water Surface Elevation1652.0 ft
Spillway Type
Auxiliary SpillwayNo
Spillway Capacity at Elevation3150.0 cfs at 1691.0 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation4450.0 cfs at 1691.0 ft
Diversion Capacity at Elevation
Drainage Area1466.0 sq mi
Hydrometeorological Report (HMR)HMR 51 & 52
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationOklahoma-Texas Area Office
Address5316 HWY 290 W, Suite 510
CityAustin, TX 78735-8931
Phone (Office)512 899-4150
Phone (FAX)512 899-4179
OrganizationFoss Reservoir Master Conservancy District
AddressBox 102
CityFoss, OK 73647-9616
Phone (Office)405 592-4421

Last updated: Mar 29, 2013