Lost Lake, located in Kremmling, Colorado, is a privately owned reservoir primarily used for irrigation purposes. Built in 1924, this Earth dam stands at a height of 10 feet and has a storage capacity of 100 acre-feet. The reservoir has a low hazard potential and a moderate risk assessment rating, making it a relatively safe structure in terms of potential hazards.

Despite being privately owned, Lost Lake is regulated by the Colorado Division of Water Resources, ensuring that it meets state standards for inspection, enforcement, and permitting. The dam has a spillway width of 10 feet and a maximum discharge capacity of 210 cubic feet per second. While the reservoir's drainage area is listed as 0, it covers a surface area of 10 acres and is situated along Brush Creek.

Although Lost Lake has not been inspected since 1986, its condition assessment remains unrated. The lack of recent maintenance and evaluation may pose some concern, but the reservoir's low hazard potential and moderate risk assessment suggest that any potential issues are manageable. With its historical significance and continued functionality for irrigation purposes, Lost Lake stands as a testament to the importance of water resource management in the face of changing climates and environmental challenges.