Dillon
Dillon is an earth dam located in Summit County, Colorado, built in 1963. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Dillon
The primary purpose of Dillon 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 Denver Board Of Water Commissioners (public utility). It impounds the Blue River near Silverthorne.
The dam stands 310 feet tall and stretches 5,900 feet across, creates a reservoir covering 3,300 acres, has a maximum storage capacity of 305,000 acre-feet, and collects water from a drainage area of 338 square miles. Completed in 1963, 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 07/27/2022.
At 310 feet, this dam is taller than 99% 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 | Summit |
| Nearest City | Silverthorne |
| River/Stream | Blue River |
| Coordinates | 39.61833, -106.06557 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 310 ft |
| Dam Height | 231 ft |
| Dam Length | 5,900 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 305,000 acre-ft |
| Max Storage | 305,000 acre-ft |
| Normal Storage | 254,036 acre-ft |
| Surface Area | 3,300 acres |
| Drainage Area | 338 sq mi |
| Max Discharge | 11,754 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | DENVER BOARD OF WATER COMMISSIONERS |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 07/27/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CO00875 |
| Federal ID | CO00875 |
| More Info | State Dam Safety Program |