Carter Lake Dam
Three dams help form Carter Lake Reservoir. The Reservoir is one of two final storage locations for water diverted from Colorado's West Slope via the Colorado-Big Thompson Project. Water exits the reservoir through Dam #1 and the St. Vrain Supply Canal serving communities ranging from Longmont to Boulder and Fort Morgan, Colorado before water is returned to the South Platte River system.
Dam No. 1, the largest, occupies a gap across the Dakota sandstone hogback, and ifs founded on Morrison shale and limestone and the Sundance sandstone. The abutments are Dakota sandstone and shale, and all the strata have about 15 degree dip downstream.
The geology of Dam No. 2 is somewhat more complex. Due to sharp echelon folding, the hogback structure ends abruptly against a southward plunging anticline. The result is that the foundation strata dip to the southwest into the right abutment, with dips varying from 5 degrees on the right abutment to 70 degrees on the left abutment. The dam rests on upturned edges of the Morrison shale and limestone, Sundance sandstone and the Lykins formation.
Dam No. 3 rests entirely on Lyons sandstone.
|Region||Facilities in Great Plains | Great Plains Home Page|
|National ID Number||CO01650|
|Hydrologic Unit Code|
|Structural Height||214.0 ft|
|Hydraulic Height (Normal Operating Depth at Dam)||190.0 ft|
|Top Parapet (Elevation)|
|Spillway Crest Elevation|
|Crest Elevation||5769.0 ft|
|Crest Length||1235.0 ft|
|Volume of Dam Construction Materials|
|Streambed at Dam Axis||5579.0 ft|
|Top of Exclusive Flood Control Pool (Elevation)|
|Top of Joint Use Pool (Elevation)|
|Top of Active Conservation Pool (Elevation)||5759.0 ft|
|Top of Inactive Conservation Pool (Elevation)||5640.0 ft|
|Top of Dead Storage Pool (Elevation)||5618.0 ft|
|Total Water Storage at Elevation|
|Maximum Water Surface Elevation|
|Normal Water Surface Elevation||5759.0 ft|
|Spillway Capacity at Elevation|
|Auxiliary Spillway Capacity at Elevation|
|Uncontrolled Spillway Capacity at Elevation|
|Outlet Works Capacity at Elevation||1200 cfs at 5763.0 ft|
|Diversion Capacity at Elevation|
|Drainage Area||3.7 sq mi|
|Hydrometeorological Report (HMR)||HMR 55|
|Probable Maximum Flood (PMF) Report|