Longmont Reservoir
Longmont Reservoir is a concrete dam located in Boulder County, Colorado, built in 1900. It carries a Low hazard potential classification and has a unsatisfactory condition assessment.
About Longmont Reservoir
The primary purpose of Longmont Reservoir 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 Longmont (huson, Ken) (local government). It impounds the North St. Vrain Creek near Lyons.
The dam stands 30 feet tall and stretches 110 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 75 acre-feet, and collects water from a drainage area of 108 square miles. Completed in 1900, the structure is over a century old.
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 unsatisfactory, indicating serious safety deficiencies exist that require immediate attention or remedial action. The most recent inspection on record was 04/13/2015. That was over 10 years ago.
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Location
| State | Colorado |
| County | Boulder |
| Nearest City | Lyons |
| River/Stream | North St. Vrain Creek |
| Coordinates | 40.22945, -105.34584 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 30 ft |
| Dam Height | 30 ft |
| Dam Length | 110 ft |
| Year Completed | 1900 (126 years old) |
Storage & Hydraulics
| NID Storage | 75 acre-ft |
| Max Storage | 75 acre-ft |
| Normal Storage | 75 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 108 sq mi |
| Max Discharge | 3,000 cfs |
| Spillway Type | None |
Ownership & Safety
| Purpose | Water Supply |
| Owner | CITY OF LONGMONT (HUSON, KEN) |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Unsatisfactory |
| Last Inspection | 04/13/2015 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | CO02369 |
| Federal ID | CO02369 |
| More Info | State Dam Safety Program |