Upper Big Nemaha 12-b is an earth dam located in Lancaster County, Nebraska, built in 1994. It carries a Low hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 36 ft36 ft tall and 1,231 ft long, taller than 82% 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 12-b
Upper Big Nemaha 12-b is a dam in Lancaster, Nebraska. The dam is owned by Nemaha Natural Resources District (local government). It impounds the Tr-mid Br Big Nemaha River near Firth.
The dam stands 36 feet tall and stretches 1,231 feet across, creates a reservoir covering 94 acres, has a maximum storage capacity of 1,231 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1994, the structure is 32 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 06/14/2021.
At 36 feet, this dam is taller than 82% of dams nationwide.
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Location
| State | Nebraska |
| County | Lancaster |
| Nearest City | Firth |
| River/Stream | Tr-mid Br Big Nemaha River |
| Coordinates | 40.52948, -96.63704 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 36 ft |
| Dam Height | 29 ft |
| Dam Length | 1,231 ft |
| Year Completed | 1994 (32 years old) |
Storage & Hydraulics
| NID Storage | 1,231 acre-ft |
| Max Storage | 1,231 acre-ft |
| Normal Storage | 251 acre-ft |
| Surface Area | 94 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 632 cfs |
Ownership & Safety
| Purpose | Other |
| Owner | Nemaha Natural Resources District |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/14/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | NE02365 |
| Federal ID | NE02365 |
| More Info | State Dam Safety Program |