Anchor Dam is a dam in Hot Springs County, Wyoming, about 35 miles (56 km) west of Thermopolis.

Anchor Dam
Anchor Dam
CountryUnited States
LocationHot Springs County, Wyoming
Coordinates43°39′51″N 108°49′28″W / 43.66410°N 108.82450°W / 43.66410; -108.82450
PurposeIrrigation
StatusOperational, but not as designed
Operator(s)Owl Creek Irrigation District
Dam and spillways
Type of damArch dam
ImpoundsSouth Fork of Owl Creek
Height (foundation)208 feet (63 m)
Reservoir
CreatesAnchor Reservoir
Total capacity17,400 acre-feet (21,500,000 m3) (designed)

The concrete thin-arch dam was completed in 1960 by the United States Bureau of Reclamation as a water storage project. The 208-foot (63 m)-high dam structure impounds the water of the South Fork of Owl Creek, with the spillway as designed as a central overflow.

During construction, the discovery of solution cavities in the bedrock forced the re-positioning and re-configuration of the dam, causing delays and added expense. The same karst solution cavities prevented Anchor Reservoir from filling its design capacity of 17,400 acre-feet (21,500,000 m3). It has never been full. More than 50 sinkholes had been identified in the underlying Chugwater Formation geology of the reservoir basin, with at least one of them 30 feet (9.1 m) in diameter and 35 feet (11 m) deep. The site's lack of "hydraulic integrity" was well known to Bureau scientists before and during construction.[1]

The reservoir fills enough to provide some irrigation benefit through July and August of each season.[2] It is operated by the local Owl Creek Irrigation District.[3]

References

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  1. ^ Jarvis, Todd (2003). "The Money Pit: Karst Failure of Anchor Dam, Wyoming" (PDF). Oklahoma Geological Survey Circular. 109: 271–278 – via aquadoc.typepad.com.
  2. ^ Jean, Renée (July 8, 2024). "Anchor Dam: After A Decade And Millions Spent,…". Cowboy State Daily. Retrieved July 6, 2024.
  3. ^ "Owl Creek Unit - Project Details". United States Bureau of Reclamation. Archived from the original on December 14, 2012.