Upper Big Nemaha 21-a
Upper Big Nemaha 21-a is an earth dam located in Otoe County, Nebraska, built in 1983. It carries a Low hazard potential classification and has a satisfactory condition assessment.
About Upper Big Nemaha 21-a
The primary purpose of Upper Big Nemaha 21-a 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 Nemaha Natural Resources District (local government). It impounds the Tr-mid Br Big Nemaha River near Sterling.
The dam stands 33 feet tall and stretches 908 feet across, creates a reservoir covering 24 acres, has a maximum storage capacity of 427 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1983, the structure is 43 years 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 06/21/2021.
At 33 feet, this dam is taller than 78% of dams nationwide.
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Location
| State | Nebraska |
| County | Otoe |
| Nearest City | Sterling |
| River/Stream | Tr-mid Br Big Nemaha River |
| Coordinates | 40.52801, -96.45698 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 33 ft |
| Dam Height | 33 ft |
| Dam Length | 908 ft |
| Year Completed | 1983 (43 years old) |
Storage & Hydraulics
| NID Storage | 427 acre-ft |
| Max Storage | 427 acre-ft |
| Normal Storage | 131 acre-ft |
| Surface Area | 24 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 300 cfs |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Nemaha Natural Resources District |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/21/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | NE01895 |
| Federal ID | NE01895 |
| More Info | State Dam Safety Program |