Phelps is a privately owned irrigation dam located on McMurray Creek in Platte, Wyoming. Completed in 1911, this earth dam stands at 28 feet high with a hydraulic height of 26 feet and a length of 730 feet. It serves the primary purpose of irrigation, providing a storage capacity of 138 acre-feet and a normal storage level of 96 acre-feet. Despite its age, Phelps is classified as having a low hazard potential but is assessed as being in poor condition as of the last inspection in August 2018.

Situated in the Omaha District of the US Army Corps of Engineers, Phelps is regulated by the State of Wyoming and subject to state jurisdiction, permitting, inspection, and enforcement. The dam features an uncontrolled spillway with a width of 25 feet and a single slide (sluice gate) outlet gate. With a moderate risk assessment rating of 3, Phelps may require risk management measures in the future to ensure its continued safety and functionality. With its historical significance and importance to local irrigation practices, Phelps remains a key water resource structure in the region.

Water resource and climate enthusiasts interested in the intersection of infrastructure, water management, and environmental sustainability will find Phelps to be a fascinating case study. Its age, design, and condition present challenges and opportunities for maintaining water security in the face of changing climate conditions. As a vital component of the local irrigation system, Phelps underscores the importance of proactive risk assessment and management to ensure the safety and reliability of critical water infrastructure in Wyoming.