Upper Big Nemaha 9-a is an earth dam located in Gage County, Nebraska, built in 1985. It carries a Low hazard potential classification and has a poor condition assessment.
Dam profile
NID height · 34 ft34 ft tall and 866 ft long, taller than 78% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Upper Big Nemaha 9-a
The primary purpose of Upper Big Nemaha 9-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 Adams.
The dam stands 34 feet tall and stretches 866 feet across, creates a reservoir covering 9 acres, has a maximum storage capacity of 309 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1985, the structure is 41 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 06/03/2020.
At 34 feet, this dam is taller than 78% of dams nationwide.
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Location
| State | Nebraska |
| County | Gage |
| Nearest City | Adams |
| River/Stream | Tr-mid Br Big Nemaha River |
| Coordinates | 40.50196, -96.54594 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 34 ft |
| Dam Height | 27 ft |
| Dam Length | 866 ft |
| Year Completed | 1985 (41 years old) |
Storage & Hydraulics
| NID Storage | 309 acre-ft |
| Max Storage | 309 acre-ft |
| Normal Storage | 66 acre-ft |
| Surface Area | 9 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 180 cfs |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Nemaha Natural Resources District |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 06/03/2020 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | NE02229 |
| Federal ID | NE02229 |
| More Info | State Dam Safety Program |