Nyswonger Dam dam
Nyswonger Dam
Nyswonger Dam, located in Warren County, Iowa, was completed in 1970 and is owned and regulated by a private entity. The dam, designed by the USDA NRCS, serves multiple purposes including fire protection, stock and small fish pond management, and recreation. With a low hazard potential and a moderate risk assessment rating of 3, Nyswonger Dam stands at 30 feet tall and spans 492 feet in length, holding a maximum storage capacity of 74 acre-feet.
Situated on the TR-Middle River, Nyswonger Dam plays a crucial role in water resource management, providing water for various uses while maintaining a surface area of 5.3 acres. Despite its age, the dam has not been rated for its condition and has not undergone recent inspections. However, with state jurisdiction and regulation by the Iowa DNR, Nyswonger Dam remains a key infrastructure for the community of SUMMERSET, offering essential services and recreational opportunities while ensuring the safety and sustainability of the surrounding environment.
As a significant earth dam in the region, Nyswonger Dam operates with an uncontrolled spillway type and a soil foundation. While there are no outlet gates or associated structures, the dam's primary purpose of fire protection and stock management highlights its importance in safeguarding the local area from potential hazards. With a risk management plan in place and a history of moderate risk assessment, Nyswonger Dam continues to demonstrate its value in water resource management and climate resilience efforts within the state of Iowa.
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 Nyswonger Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Middle River Near Indianola | 1,120 cfs | → |
| South River Near Ackworth | 1,990 cfs | → |
| North River Near Norwalk | 1,200 cfs | → |
| Des Moines River Blw Raccoon Riv At Des Moines | 10,200 cfs | → |
| Raccoon River At 63rd Street At Des Moines | 2,970 cfs | → |
| Raccoon River At Fleur Drive | 2,900 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Nyswonger Dam.
Boat launches
- 118th Avenue Warren County
- Pershing Street Warren County
- County Park Des Moines
- Polk County
- Southeast Vandalia Drive Pleasant Hill
Track Nyswonger 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 Nyswonger Dam
Where does the data for Nyswonger 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 Nyswonger Dam.