Lake John
Lake John is an earth dam located in Jackson County, Colorado, built in 1957. It carries a Significant hazard potential classification and has a fair condition assessment.
About Lake John
The primary purpose of Lake John is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Colorado Parks And Wildlife (state). It impounds the N Fk North Platte-tr near Cowdrey.
The dam stands 27 feet tall and stretches 1,723 feet across, creates a reservoir covering 612 acres, has a maximum storage capacity of 16,128 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1957, the structure is well into its service life at over 50 years old.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 12/03/2021.
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Location
| State | Colorado |
| County | Jackson |
| Nearest City | Cowdrey |
| River/Stream | N Fk North Platte-tr |
| Coordinates | 40.76720, -106.46207 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 27 ft |
| Dam Height | 25 ft |
| Dam Length | 1,723 ft |
| Year Completed | 1957 (69 years old) |
Storage & Hydraulics
| NID Storage | 16,128 acre-ft |
| Max Storage | 16,128 acre-ft |
| Normal Storage | 7,092 acre-ft |
| Surface Area | 612 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 2,800 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | COLORADO PARKS AND WILDLIFE |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 12/03/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CO00993 |
| Federal ID | CO00993 |
| More Info | State Dam Safety Program |