Dunnagan is a privately owned irrigation dam located in Colorado, specifically in Archuleta County near Blanco, NM. Built in 1949 by the USDA NRCS, this earth dam stands at a height of 19 feet and has a length of 569 feet, with a storage capacity of 201 acre-feet. The primary purpose of Dunnagan is irrigation, serving the surrounding area with water from the Roush Draw river or stream.

Although Dunnagan has a low hazard potential and is currently in a not-rated condition, it is regulated by the Colorado Department of Water Resources. The dam has not been inspected since 1987, with an inspection frequency of every 6 years. Despite the moderate risk assessment rating, there are no specific risk management measures or emergency action plans in place for Dunnagan. The dam also features an uncontrolled spillway and has a maximum discharge of 378 cubic feet per second.

Enthusiasts of water resources and climate will find Dunnagan intriguing due to its historical significance in providing irrigation water in the region. With its location near Blanco, NM and the Roush Draw river, this dam plays a vital role in the agricultural landscape of Archuleta County. As efforts to manage and maintain water resources continue, Dunnagan stands as a reminder of the importance of infrastructure in sustaining agricultural practices in Colorado.