Holly

About Holly

The primary purpose of Holly is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Urban Drainage & Flood Control District (thomas, S (local government). It impounds the Little Dry Creek near Littleton.

The dam stands 45 feet tall and stretches 1,170 feet across, creates a reservoir covering 23 acres, has a maximum storage capacity of 455 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1979, the structure is 47 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 09/29/2021.

At 45 feet, this dam is taller than 91% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Colorado dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.