Located in Boulder, Colorado, Los Lagos No. 3 is a privately-owned earth dam built in 1894 by the USDA NRCS for irrigation purposes. With a height of 10 feet and a length of 75 feet, this dam has a storage capacity of 71 acre-feet and serves multiple purposes including fire protection, stock, small fish pond, irrigation, and water supply. The dam is regulated by the Colorado Department of Water Resources and undergoes regular inspections to ensure its structural integrity.

The dam's spillway is uncontrolled with a width of 5 feet, and it has a significant hazard potential, although its condition is currently assessed as satisfactory. The last inspection took place in June 2020, with a frequency of every two years. The risk assessment for Los Lagos No. 3 is moderate, indicating a level 3 risk, but no specific risk management measures have been outlined at this time. As a key feature in the Beaver Creek watershed, this dam plays a crucial role in water resource management and climate resilience efforts in the area.

Overall, Los Lagos No. 3 stands as a historic and essential infrastructure for water supply and irrigation in Boulder, Colorado. With its long-standing presence and multi-purpose functionality, this dam continues to be a focal point for water resource enthusiasts and climate advocates interested in sustainable water management practices. As efforts to address climate change and water scarcity intensify, Los Lagos No. 3 serves as a reminder of the importance of maintaining and regulating water infrastructure for the benefit of both human and environmental needs.