Boulder - South
Boulder - South is an earth dam located in Boulder County, Colorado, built in 1955. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Boulder - South
The primary purpose of Boulder - South is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by City Of Boulder (kevin Clark) (local government). It impounds the Little Dry Creek near Boulder.
The dam stands 59 feet tall and stretches 3,198 feet across, creates a reservoir covering 684 acres, has a maximum storage capacity of 17,700 acre-feet, and collects water from a drainage area of 14 square miles. Completed in 1955, the structure is well into its service life at over 50 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 11/03/2022.
At 59 feet, this dam is taller than 95% of all dams in the United States.
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.
Location
| State | Colorado |
| County | Boulder |
| Nearest City | Boulder |
| River/Stream | Little Dry Creek |
| Coordinates | 40.07584, -105.21335 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 59 ft |
| Dam Height | 45 ft |
| Dam Length | 3,198 ft |
| Year Completed | 1955 (71 years old) |
Storage & Hydraulics
| NID Storage | 17,700 acre-ft |
| Max Storage | 17,700 acre-ft |
| Normal Storage | 13,300 acre-ft |
| Surface Area | 684 acres |
| Drainage Area | 14 sq mi |
| Max Discharge | 25,500 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | CITY OF BOULDER (KEVIN CLARK) |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/03/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CO02819 |
| Federal ID | CO02819 |
| More Info | State Dam Safety Program |