Onapa Lake
Onapa Lake is an earth dam located in McIntosh County, Oklahoma, built in 1935. It carries a Low hazard potential classification.
About Onapa Lake
The primary purpose of Onapa Lake is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City Of Checotah (local government). It impounds the Tr-lake Eufaula near Eufaula.
The dam stands 58 feet tall and stretches 594 feet across, creates a reservoir covering 49 acres, and has a maximum storage capacity of 2,520 acre-feet. Completed in 1935, the structure is well-established, with more than 75 years of service.
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. The most recent inspection on record was 12/03/2010. That was over 15 years ago.
At 58 feet, this dam is taller than 95% of all dams in the United States.
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Location
| State | Oklahoma |
| County | McIntosh |
| Nearest City | Eufaula |
| River/Stream | Tr-lake Eufaula |
| Coordinates | 35.40359, -95.57162 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 58 ft |
| Dam Height | 58 ft |
| Dam Length | 594 ft |
| Year Completed | 1935 (91 years old) |
Storage & Hydraulics
| NID Storage | 2,520 acre-ft |
| Max Storage | 2,520 acre-ft |
| Normal Storage | 1,137 acre-ft |
| Surface Area | 49 acres |
| Max Discharge | 4,834 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | CITY OF CHECOTAH |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not Rated |
| Last Inspection | 12/03/2010 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | OK02062 |
| Federal ID | OK02062 |
| More Info | State Dam Safety Program |