Swan Lake Dam dam
Swan Lake Dam
Swan Lake Dam, located in Coon Rapids, Iowa, is a state-regulated structure completed in 1935 by the National Park Service. This earth dam, standing at a height of 10 feet and a length of 900 feet, serves as a fish and wildlife pond along a tributary to Middle Raccoon River. With a normal storage capacity of 440 acre-feet and a maximum capacity of 600 acre-feet, it covers a surface area of 130 acres and drains a watershed area of 1.4 square miles.
Despite being classified as a low hazard potential structure, Swan Lake Dam has not been rated for its condition since its last inspection in 1993. While it meets state regulatory requirements for permitting, inspection, and enforcement by the Iowa DNR, its emergency action plan (EAP) status remains unclear. The dam's association with the US Army Corps of Engineers (USACE) is also noted as non-existent, suggesting that its operations and maintenance fall under state jurisdiction.
For water resource and climate enthusiasts, Swan Lake Dam presents a unique opportunity to study the intersection of human-made structures with natural ecosystems. Its role in providing habitat for fish and wildlife, coupled with its historical significance as a New Deal-era project, offers a window into the complex relationships between infrastructure, conservation, and community development. As efforts to modernize dam safety and resilience continue, understanding the context and characteristics of structures like Swan Lake Dam becomes essential for sustainable water management in the face of a changing climate.
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 Swan Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| North Raccoon River Near Sac City | 261 cfs | → |
| North Raccoon River Near Jefferson | 693 cfs | → |
| Middle Raccoon River Near Bayard | 210 cfs | → |
| Middle Raccoon River At Panora | 161 cfs | → |
| Des Moines River Near Stratford | 2,870 cfs | → |
| Des Moines River At Fort Dodge | 2,170 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Swan Lake Dam.
Boat launches
Campgrounds
Track Swan Lake 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 Swan Lake Dam
Where does the data for Swan Lake 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 Swan Lake Dam.