Sunset Lake
Sunset Lake is an earth dam located in Boulder County, Colorado. It carries a Low hazard potential classification and has a fair condition assessment.
About Sunset Lake
The primary purpose of Sunset Lake 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 St Vrain near Longmont.
The dam stands 15 feet tall and stretches 700 feet across, creates a reservoir covering 16 acres, and has a maximum storage capacity of 260 acre-feet.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 11/02/2021.
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Location
| State | Colorado |
| County | Boulder |
| Nearest City | Longmont |
| River/Stream | St Vrain |
| Coordinates | 40.18442, -105.17369 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 11 ft |
| Dam Length | 700 ft |
Storage & Hydraulics
| NID Storage | 260 acre-ft |
| Max Storage | 260 acre-ft |
| Normal Storage | 173 acre-ft |
| Surface Area | 16 acres |
| Max Discharge | 1,200 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | BOULDER COUNTY PARKS AND OPEN SPACE (ALEXANDER, RO |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 11/02/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | CO03009 |
| Federal ID | CO03009 |
| More Info | State Dam Safety Program |