Mc Lellan, also known as Englewood #1 and Dad Clark Gulch, is a local government-owned dam in Arapahoe County, Colorado, designed by W.W. Wheeler. Completed in 1964, this Earth dam stands at a height of 111 feet and serves primarily for water supply purposes. With a maximum storage capacity of 9700 acre-feet and a normal storage of 6200 acre-feet, Mc Lellan plays a crucial role in water resource management in the region.

The dam has a spillway width of 102 feet and a high hazard potential, although its condition assessment was deemed satisfactory as of April 2020. The structure has undergone modifications in 1969, 1982, and 2002 to reinforce its foundation and structural integrity. Located in Littleton, Colorado, Mc Lellan overlooks the Dad Clark Gulch and has a drainage area of 9 square miles, with a surface area of 217 acres.

Despite its moderate risk assessment, Mc Lellan remains a key hydraulic infrastructure in the area, with state-regulated operations and inspections ensuring its continued functionality and safety for surrounding communities. Its presence highlights the importance of effective dam management practices in safeguarding water resources and mitigating climate-related risks in the region.