Lewis Dam dam
Lewis Dam
Lewis Dam, located in Percival, Iowa, is a privately owned recreational structure designed by the NRCS in 2002. Standing at 27 feet tall and spanning 400 feet in length, this stone core dam plays a vital role in managing water resources in the area. With a storage capacity of 35 acre-feet and a maximum discharge of 64 cubic feet per second, Lewis Dam helps regulate the flow of water in the tributary to Horse Creek, providing essential support for the surrounding ecosystem.
The dam, regulated by the Iowa Department of Natural Resources, is classified as having a low hazard potential and a moderate risk level. While the condition assessment is currently not rated, the dam has undergone regular inspections since its completion. With a spillway width of 34 feet and uncontrolled spillway type, Lewis Dam ensures the safe release of excess water during periods of high flow. Despite its primary purpose being recreation, the dam also contributes to flood control and water supply management in the Fremont County area.
As a key feature in the region's water infrastructure, Lewis Dam serves as a reminder of the importance of sound engineering practices in mitigating the impacts of climate change. With its strategic location and design, the dam exemplifies the collaborative efforts between private owners, regulatory agencies, and designers in safeguarding water resources for both recreational and environmental purposes. Its role in water management and risk reduction underscores the significance of investing in sustainable infrastructure for a resilient future.
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 Lewis Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Missouri River At Nebraska City | 32,800 cfs | → |
| Nishnabotna River Above Hamburg | 1,520 cfs | → |
| West Nishnabotna River At Randolph | 684 cfs | → |
| Weeping Water Creek At Union | 16 cfs | → |
| Little Nemaha River At Auburn | 98 cfs | → |
| East Nishnabotna River At Red Oak | 574 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lewis Dam.
Boat launches
- Riverview Boat Ramp
- Peru Boat Ramp
- Wilson Creek
- Prairie Owl
- Plattsmouth Boat Ramp
- 165 Street Atchison County
Track Lewis 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 Lewis Dam
Where does the data for Lewis 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 Lewis Dam.