Henry Dam dam
Henry Dam
Henry Dam, located in Dow City, Iowa, is a privately owned earth dam completed in 1960 for fire protection, stock, and small fish pond purposes. The dam has a height of 34 feet, a length of 378 feet, and a storage capacity of 82 acre-feet. Situated on Paradise Creek, the dam serves the dual purpose of providing water for various needs while also minimizing the risk of flooding in the area. Despite being classified as having a low hazard potential, the dam is subject to regulation, inspection, and enforcement by the Iowa Department of Natural Resources.
Managed by the Natural Resources Conservation Service, Henry Dam has not been rated for its condition assessment but is considered to have a moderate risk level. The dam's emergency action plan status, compliance with guidelines, and risk management measures are currently unspecified. While the dam's structure and foundation consist of soil, its spillway is uncontrolled with a spillway width of zero. The dam's location in Crawford County, Iowa, highlights its importance in water resource management and climate resilience efforts in the region.
As a significant water resource infrastructure in the Rock Island District, Henry Dam plays a vital role in the local community, providing essential services for fire protection, agriculture, and wildlife habitat. With its historical significance dating back to the 1960s, the dam continues to be monitored for safety and regulatory compliance by the Iowa DNR. Water resource and climate enthusiasts can appreciate the unique blend of functionality and environmental stewardship that Henry Dam represents in its contribution to sustainable water management practices in 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 Henry Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Maple River At Mapleton | 264 cfs | → |
| Little Sioux River Near Turin | 1,680 cfs | → |
| Monona-Harrison Ditch Near Turin | 187 cfs | → |
| Soldier River At Pisgah | 125 cfs | → |
| Boyer River At Logan | 432 cfs | → |
| West Fork Ditch At Hornick | 80 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Henry Dam.
Boat launches
Track Henry 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 Henry Dam
Where does the data for Henry 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 Henry Dam.