Horsetooth Dam

Rocks underlying the site consist of various sedimentary types that range in age from Pennsylvanian to Recent.  These units contain formations such as; the Lower Morrison, Sundance, Lykins, Dakota and Upper Lyons.  Individual beds in these formations at the site strike 15-20 degrees northwest and dip 27 to 38 degrees northeast.   On the greater part of the dam site overburden is thin and ranges from zero to five feet.  In a zone about 400 feet wide near the center of the site and at right angles to the axis, the overburden varies from 15 to 32 feet in thickness.  This material is reddish silty sandy clay having the appearance of windblown material.  It stands up well in test pits, some of which were dug to 20 feet or more without cribbing.  It contains practically no boulders.

RegionFacilities in Great Plains | Great Plains Home Page
ProjectColorado-Big Thompson
Dam Type
WatercourseOffstream Storage
Original Construction1946-1949
Modified Construction
National ID NumberCO01659
Hydrologic Unit Code

Structural Height155.0 ft
Hydraulic Height (Normal Operating Depth at Dam)
Top Parapet (Elevation)
Spillway Crest Elevation
Crest Elevation5443.0 ft
Crest Length1840.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)5430.0 ft
Top of Inactive Conservation Pool (Elevation)5325.0 ft
Top of Dead Storage Pool (Elevation)5270.0 ft

Hydraulics & Hydrology
Total Water Storage at Elevation
Maximum Water Surface Elevation
Normal Water Surface Elevation5430.0 ft
Spillway Type
Auxiliary SpillwayNo
Spillway Capacity at Elevation0 cfs at 0 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation2500 cfs at 5430.0 ft
Diversion Capacity at Elevation
Drainage Area17.0 sq mi
Hydrometeorological Report (HMR)HMR 55
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationEastern Colorado Area Office
Address11056 W. County Rd 18E
CityLoveland, CO 80537-9711
Phone (Fax)970 663-3212
Phone (Office)970 667-4410
OrganizationNorthern Colorado Water Conservancy District
AddressPO Box 679
CityLoveland, CO 80539
Phone (Office)970 667-2437

Last updated: Mar 29, 2013