The foundation of Mountain Park Dam consists of Cambrian granite which has been intruded by diabase. The granite is hard, fine to medium rystalline, pink to grayish pink, and weathered to a depth of about 2 inches along joints near the surface. It is intricately cut by joints, shear, and faults.
The canyon in which the dam is constructed is fault and joint controlled. A fault zone approximately 62 feet wide is present in the canyon floor and lies beneath the central portion of the dam. This zone is characterized by sheared, pulverized, granular, slickensided diabase with some granite between the diabase intrusions. The granite in this zone is hard to soft and easily broken. The zone, known as the plug area, was over excavated to a depth of 25 feet, backfilled with concrete, and then grouted. Other areas of soft rock in the abutments and foundation area were also over excavated to a minimum depth of 5 feet, then backfilled with concrete. The foundation area and abutments were grouted before placing concrete.
Mountain Park Dam forms Tom Steed Reservoir, and regulates natural flows of West Otter Creek and diverted flows from Elk Creek to provide municipal and industiral water supplies for the cities of Altus, Snyder, and Frederick, Oklahoma. The water is conveyed from the reservoir to the project cities through an aquaduct system that consists of 40 miles of pipeline, two pumping plants, a chlorination station, and other appurtenant facilities.
|Watercourse||West Otter Creek|
|National ID Number||OK20502|
|Base Width||17.0 ft|
|Crest Elevation||1423.0 ft|
|Top Parapet (Elevation)||1427.0 ft|
|Structural Height||133.0 ft|
|Hydraulic Height (Normal Operating Depth at Dam)||59.0 ft|
|Crest Length||535.0 ft|
|Crest Width||6.0 ft|
|Volume of Dam Construction Materials||18160.0 cu yd|
Hydraulics & Hydrology
|Total Water Storage at Elevation||117825 acre-ft at 1414|
|Spillway Capacity at Elevation||38300 cfs at 1423.6|
|Outlet Works Capacity at Elevation||44 cfs at 1414 ft|
|Drainage Area||121 sq mi|
|Hydrometeorological Report (HMR)||HMR 51 & 52|
|Maximum Water Surface Elevation||1427.0 ft|