Winsor Dam on Santa Clara Creek

WASHINGTON COUNTY HISTORICAL SOCIETY     (Washington County, Utah)

SHEM DAM   (aka WINSOR DAM)

on the Santa Clara River/Creek

LOCATION

The Shem Dam is located on the Santa Clara River in Washington County, Utah.
It is on the west side of County Road 3184, 0.9 miles north of Old Highway 91.

37° 11' 31.90" North Latitude,   113° 46' 11.11" West Longitude
37.1922 North Latitude,   113.7698 West Longitude
3,402 feet (991 meters) MSL

Area around Winsor Dam


The Winsor Dam is on the Shivwits Indian Reservation. Please respect this private property by not trespassing.
Trespassers will be prosecuted.


DESCRIPTION

TBD
For a more detailed description, click here.


HISTORY SUMMARY

The original Shem Dam structure was constructed in 1909 as a brush and concrete structure approximately 600 feet upstream from the current dam location. The brush and concrete dam washed out in the spring of 1932 during a flood.
For more details on this original dam, click here.

In 1933 and 1934, a concrete and basalt boulder dam (current dam) was constructed by Company 961 out of the Zion Civilian Conservation Corps (CCC) Camp. It is one of the largest dams built by the CCC in Utah. In addition to serving as a flood control structure on the Santa Clara River, Shem Dam diverted irrigation water to fields downstream on the Santa Clara Bench, cultivated by residents of the communities of Ivins, Santa Clara, and St. George. A diversion below the dam also routed irrigation water to lands cultivated by the residents of the Shivwits Indian Reservation.
For more details on this original dam, click here.

Shem Dam was damaged by a major flood in 1938 but was repaired
For more details on this flood and the repair, click here.

By 1941, the area immediately upstream of the Shem Dam was filled with silt and debris to the level of the crest of the spillway.
For more details on this silt and debris buildup, click here.

A 1955 flood destroyed the downstream side of the crest and damaged the east abutment. The dam was repaired in 1958.
For more details on this flood and the repair, click here.

The dam stopped serving as an irrigation diversion in 2003

In 2011, the dam was again heavily damaged by a flood raising concerns about its structural integrity and ability to withstand future flood events.
For more details on this flood and the repair, click here.

The 2011 flood prompted a Shem Dam Rehabilitation Project, sponsored by the U.S. Department of Agriculture, Natural Resources Conservation Service (NRCS), under the authority of the Emergency Watershed Protection program.
For more details on this rehabilitation, click here.


PHOTOS

Winsor Dam on Santa Clara Creek
WCHS-01033   Winsor Dam on the Santa Clara Creek

Other WCHS photos:
WCHS-01795   Photo of the Winsor Dam partially obscured by foliage
WCHS-01796   Photo of the water channel coming through the Winsor Dam
WCHS-03914   Photo of the Shem Dam spillway carrying spring runoff in 1937
WCHS-03915   Photo of a portion of the Shem Dam spillway carrying spring runoff in 1937


REFERENCES

Shem Dam Rehabilitation Project Overview
Shem Dam Rehabilitation Project Meeting, June6 2013

Draft Environmental Assessment (EA) for the Rehabilitation of Shem Dam
Prepared by McMillen, LLC for the USDA Natural Resources Conservation Service
January 2014
[Large file, so this may take a while to load]

Historic American Engineering Record, Shem Dam (Winsor Dam), HAER No. UT-96
Prepared by Scott O'Mack, William Self Associates, Inc.,
    for the USDA Natural Resources Conservation Service (NRCS)
March 2016, 96 Pages
[Large file, so this may take a while to load]

Shem Dam rehab complete, last of 10 years of flood repair projects
Article by Julie Applegate, St. George News, June 4, 2015