Polly A. Deane
Polly A. Deane is an earth dam located in Jefferson County, Colorado, built in 1908. It carries a High hazard potential classification and has a unsatisfactory condition assessment.
About Polly A. Deane
The primary purpose of Polly A. Deane is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bergen Ditch & Reservoir Company (easton, Robert) (private). It impounds the Dutch Creek-os near Littleton.
The dam stands 28 feet tall and stretches 1,230 feet across, creates a reservoir covering 38 acres, and has a maximum storage capacity of 760 acre-feet. Completed in 1908, the structure is over a century 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 unsatisfactory, indicating serious safety deficiencies exist that require immediate attention or remedial action. An emergency action plan is in place for this dam. The most recent inspection on record was 11/23/2021.
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 | Jefferson |
| Nearest City | Littleton |
| River/Stream | Dutch Creek-os |
| Coordinates | 39.60568, -105.13815 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 28 ft |
| Dam Height | 20 ft |
| Dam Length | 1,230 ft |
| Year Completed | 1908 (118 years old) |
Storage & Hydraulics
| NID Storage | 760 acre-ft |
| Max Storage | 760 acre-ft |
| Normal Storage | 512 acre-ft |
| Surface Area | 38 acres |
| Max Discharge | 1,150 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | BERGEN DITCH & RESERVOIR COMPANY (EASTON, ROBERT) |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Unsatisfactory |
| Last Inspection | 11/23/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CO00336 |
| Federal ID | CO00336 |
| More Info | State Dam Safety Program |