Arcadia Upper, located in St. Anthony, Idaho, is a privately-owned irrigation dam with a rich history dating back to its completion in 1912. This earth dam, constructed with stone core types on rock and soil foundations, stands at a height of 21 feet and spans 550 feet in length. Its primary purpose is irrigation, serving as a vital resource for managing water from Sand Creek and Henrys Fork.

Despite its age, Arcadia Upper faces challenges with a poor condition assessment, indicating the need for potential improvements. The dam's hazard potential is classified as low, but its risk assessment is very high, emphasizing the importance of ongoing monitoring and management. With a normal storage capacity of 300 acre-feet and a drainage area of 69 square miles, this structure plays a crucial role in water resource management in Fremont County, Idaho.

The dam's infrastructure includes a controlled spillway, slide gates for outlet control, and a spillway width of 2 feet. Although inspections are conducted every five years, the last assessment in 2017 revealed a poor condition. As water resource and climate enthusiasts, staying informed about the state of Arcadia Upper is essential for ensuring the safety and sustainability of this vital irrigation structure in Idaho's landscape.