Middle Big Nemaha 9 dam
Middle Big Nemaha 9
Middle Big Nemaha 9, located in Crab Orchard, Nebraska, is a local government-owned earth dam designed by USDA NRCS and completed in 1995 for the primary purpose of flood risk reduction along the TR-Yankee Creek. With a height of 39 feet and a length of 785 feet, this dam provides a maximum storage capacity of 1096 acre-feet and covers a surface area of 27 acres. Despite its low hazard potential and satisfactory condition assessment, it is regulated and inspected by the Nebraska Department of Natural Resources to ensure its functionality and safety.
Managed by the Natural Resources Conservation Service, Middle Big Nemaha 9 serves as a critical infrastructure in the region's flood risk mitigation efforts, with a drainage area of 3.8 square miles and a maximum discharge capacity of 1813 cubic feet per second. The dam's stone core and soil foundation contribute to its structural integrity, while its hydraulic height of 38 feet and structural height of 44 feet further bolster its flood control capabilities. Although last inspected in 2016, with a scheduled inspection frequency of 5 years, the dam remains an essential component in protecting the surrounding community from potential flood events.
As part of the Omaha District's water resource management strategy, Middle Big Nemaha 9 plays a vital role in safeguarding Johnson County, Nebraska, from the devastating impacts of flooding. With its well-maintained condition, the dam continues to fulfill its purpose effectively, storing excess water during peak flow periods and mitigating flood risks for the local residents and infrastructure. As water resource and climate enthusiasts, understanding the significance of structures like Middle Big Nemaha 9 is crucial in promoting sustainable water management practices and resilience against changing climatic conditions.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Middle Big Nemaha 9 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Big Blue R At Barneston Nebr | 2,280 cfs | → |
| Turkey Creek Near De Witt | 195 cfs | → |
| Salt Creek At Roca | 6 cfs | → |
| North Fork Big Nemaha River At Humboldt | 850 cfs | → |
| Turkey C Nr Seneca | 147 cfs | → |
| Little Nemaha River At Auburn | 743 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Middle Big Nemaha 9.
Track Middle Big Nemaha 9 in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Middle Big Nemaha 9
Where does the data for Middle Big Nemaha 9 come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Middle Big Nemaha 9.