Gaynor
Gaynor is an earth dam located in Boulder County, Colorado. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Gaynor
The primary purpose of Gaynor is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Boulder County Parks And Open Space (alexander, Ro (local government). It impounds the Boulder Creek-os near Longmont.
The dam stands 10 feet tall and stretches 500 feet across, creates a reservoir covering 70 acres, has a maximum storage capacity of 840 acre-feet, and collects water from a drainage area of 3 square miles.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 08/10/2022.
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Location
| State | Colorado |
| County | Boulder |
| Nearest City | Longmont |
| River/Stream | Boulder Creek-os |
| Coordinates | 40.12255, -105.11026 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 10 ft |
| Dam Height | 10 ft |
| Dam Length | 500 ft |
Storage & Hydraulics
| NID Storage | 840 acre-ft |
| Max Storage | 840 acre-ft |
| Normal Storage | 384 acre-ft |
| Surface Area | 70 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 807 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | BOULDER COUNTY PARKS AND OPEN SPACE (ALEXANDER, RO |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/10/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CO00284 |
| Federal ID | CO00284 |
| More Info | State Dam Safety Program |