Wanship Dam


Located 1.5 miles south of Wanship on the Weber River, the Wanship Dam impounds Rockport Lake. The lake has 62,100 acre-feet total capacity, and a surface area of 1,080 acres. The dam, a zoned earthfill structure, is 156 feet high, has a crest length of 2,010 feet, and contains 3,183,000 cubic yards of material. The spillway is an uncontrolled open concrete chute with a capacity of 10,800 cubic feet per second. The outlet works tunnel provides for releases to the powerplant or to the river. The outlet works has a capacity of 1,000 cubic feet per second.


Wanship Dam and Rockport Lake are located on the Weber River where it cuts through shale, siltstone and sandstone beds of the Frontier Formation of Late Creracious age.  Bedrock is primarily shale and siltstone with sandstone beds that form resistant ridges.  Impure coal and bentonite are interbedded with the shale.  The dam and reservoir are on the north limb of the Uinta Mountain uplift.  The beds dip 25 degrees to 35 degrees downstream.  Several northeast trending thrust faults cross the Weber Valley in the vicinity of the dam and reservoir.

RegionFacilities in Upper Colorado | Upper Colorado Home Page
ProjectWeber Basin
Dam TypeZoned earthfill
ReservoirRockport Lake
WatercourseWeber River
Location1.5 miles south of Wanship, UT
Original Construction1954-1957
Modified Construction
National ID NumberUT10131
Hydrologic Unit Code

Structural Height175.0 ft
Hydraulic Height (Normal Operating Depth at Dam)150.0 ft
Top Parapet (Elevation)
Spillway Crest Elevation
Crest Elevation6055.0 ft
Crest Length2015.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis5899.0 ft
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)
Top of Inactive Conservation Pool (Elevation)
Top of Dead Storage Pool (Elevation)5930.0 ft

Hydraulics & Hydrology
Total Water Storage at Elevation
Maximum Water Surface Elevation6049.0 ft
Normal Water Surface Elevation
Spillway Type
Auxiliary SpillwayNo
Spillway Capacity at Elevation10,800 cfs at 6049.0 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation1000 cfs at 6049.0 ft
Diversion Capacity at Elevation
Drainage Area339.0 sq mi
Hydrometeorological Report (HMR)
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationProvo Area Office
Address302 East 1860 South
CityProvo, UT 84606-7317
Phone (Office)801 379-1101
OrganizationWeber Basin Water Conservancy District
Address2837 East Hwy 193
CityLayton, UT 84040
Phone (Office)801 771-1677


Last updated: Apr 10, 2009