Louisville No. 1, located in Boulder, Colorado, is a historic earth dam completed in 1888 for water supply purposes along the Bullhead Gulch-TR river. With a height of 20 feet and a length of 2500 feet, the dam has a storage capacity of 250 acre-feet and a normal storage of 206 acre-feet. Its spillway, with a width of 50 feet, is uncontrolled, allowing for a maximum discharge of 595 cubic feet per second.

The dam, designed by Carter & Burgess, Rocky Mountain Consultants, and an unknown designer, underwent modifications in 1989 and 2001 to enhance its structural and hydraulic components. It is state-regulated by the Colorado Department of Water Resources, with inspections conducted every two years. Despite its significant hazard potential, the dam is currently in satisfactory condition according to the latest assessment in September 2020.

Managed by the local government, Louisville No. 1 serves as a vital water resource for the region, highlighting the importance of maintaining and regulating infrastructure to ensure water supply and mitigate potential risks associated with dam failure. As a focal point for water resource and climate enthusiasts, this dam represents a blend of historical significance and modern engineering practices in managing water resources for the community.