Allyn Dam dam
Allyn Dam
Allyn Dam, located in Holt, Nebraska, was completed in 1968 by the USDA NRCS with the primary purpose of flood risk reduction along the Niobrara River. This private-owned earth dam stands at a height of 25 feet and has a length of 1042 feet, providing a storage capacity of 138 acre-feet and covering a surface area of 8 acres. The dam is regulated and inspected by the Nebraska Department of Natural Resources, ensuring its structural integrity and compliance with state regulations.
Despite its low hazard potential and fair condition assessment, Allyn Dam plays a crucial role in mitigating flood risks in the region. With a maximum discharge capacity of 826 cubic feet per second, the dam helps protect surrounding areas from potential flooding events. The dam's stone core and soil foundation contribute to its stability, while its location in SES8T33R15W makes it a key feature in the flood control infrastructure of the St. Paul District.
Overall, Allyn Dam serves as a vital asset in water resource management and climate resilience efforts in Nebraska. With its history of successful flood risk reduction and ongoing state regulation and inspection, the dam remains a key component in ensuring the safety and protection of communities along the Niobrara River. As a testament to its importance, the dam continues to be maintained and monitored to uphold its role in safeguarding against potential flooding disasters.
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 Allyn Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Niobrara River At Mariaville | 1,700 cfs | → |
| Long Pine Creek Near Riverview | 208 cfs | → |
| Platte Creek Near Platte | 0 cfs | → |
| Keya Paha R At Wewela Sd | 57 cfs | → |
| Niobrara River Nr. Verdel | 2,530 cfs | → |
| Ponca Creek At Verdel | 13 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Allyn Dam.
Track Allyn Dam 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 Allyn Dam
Where does the data for Allyn Dam 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 Allyn Dam.