Koski Dam dam
Koski Dam
Located in Harrison, Iowa, the Koski Dam is a private earth dam designed by the USDA NRCS with a primary purpose of flood risk reduction. Completed in 2011, this dam stands at a height of 41 feet and stretches 500 feet in length, providing a storage capacity of 48 acre-feet and a surface area of 2 acres. Situated on a tributary to Willow Creek, the dam serves multiple purposes including fish and wildlife pond creation, grade stabilization, and recreation.
Despite its low hazard potential, the condition assessment of the Koski Dam has not been rated, and there is no information available on its emergency action plan or risk assessment. As a non-federally owned structure, the dam does not fall under the jurisdiction or regulation of any state agency. With no inspection or enforcement protocols in place, the maintenance and safety of the dam rely solely on the private owner. Despite these limitations, the Koski Dam remains a key asset in managing flood risks in the Missouri Valley area.
Water resource and climate enthusiasts can appreciate the ecological and recreational benefits provided by the Koski Dam, while also recognizing the importance of ongoing monitoring and maintenance to ensure its continued effectiveness in flood risk reduction. The collaboration between private owners and government agencies, such as the USDA NRCS, highlights the importance of partnerships in safeguarding water resources and enhancing community resilience to climate-related challenges. As discussions around climate change intensify, structures like the Koski Dam play a crucial role in mitigating the impacts of extreme weather events and protecting vulnerable communities.
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 Koski Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Soldier River At Pisgah | 127 cfs | → |
| Boyer River At Logan | 435 cfs | → |
| Little Sioux River Near Turin | 1,540 cfs | → |
| Monona-Harrison Ditch Near Turin | 183 cfs | → |
| Maple River At Mapleton | 264 cfs | → |
| Missouri River At Decatur | 26,400 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Koski Dam.
Track Koski 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 Koski Dam
Where does the data for Koski 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 Koski Dam.