Challis Lake, located in Custer County, Idaho, is a privately owned reservoir primarily used for irrigation purposes. Built in 1951, this earth dam structure stands at a height of 19.1 meters and has a normal storage capacity of 189 acre-feet. The lake covers a surface area of 20 acres and is fed by Challis Creek, providing water for agricultural activities in the region.

Despite its low hazard potential, Challis Lake has been assessed to be in poor condition, highlighting the need for maintenance and repairs to ensure its continued functionality. The dam features an uncontrolled spillway with a width of 10 feet and a maximum discharge capacity of 80 cfs. The risk assessment for Challis Lake has been classified as moderate, indicating a potential for moderate consequences in the event of a failure, emphasizing the importance of ongoing monitoring and management measures.

With its picturesque location and vital role in supporting local irrigation needs, Challis Lake serves as a crucial water resource in the region. As climate change continues to impact water availability and quality, the maintenance and upkeep of infrastructure like Challis Lake become increasingly important to ensure sustainable water management practices for future generations.