Island Lake
Island Lake is a concrete dam located in Boulder County, Colorado, built in 1890. It carries a Low hazard potential classification and has a fair condition assessment.
About Island Lake
The primary purpose of Island Lake 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 Boulder (clark, Kevin) (local government). It impounds the North Boulder Creek-tr near Boulder.
The dam stands 23 feet tall and stretches 600 feet across, creates a reservoir covering 35 acres, has a maximum storage capacity of 386 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1890, 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 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 09/06/2017.
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Location
| State | Colorado |
| County | Boulder |
| Nearest City | Boulder |
| River/Stream | North Boulder Creek-tr |
| Coordinates | 40.02948, -105.59130 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 23 ft |
| Dam Height | 18 ft |
| Dam Length | 600 ft |
| Year Completed | 1890 (136 years old) |
Storage & Hydraulics
| NID Storage | 386 acre-ft |
| Max Storage | 386 acre-ft |
| Normal Storage | 334 acre-ft |
| Surface Area | 35 acres |
| Drainage Area | 5 sq mi |
| Max Discharge | 400 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | CITY OF BOULDER (CLARK, KEVIN) |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 09/06/2017 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | CO00228 |
| Federal ID | CO00228 |
| More Info | State Dam Safety Program |