Cottonwood-Green Valley Subws 50+40 #2 dam
Cottonwood-Green Valley Subws 50+40 #2
Cottonwood-Green Valley Subws 50+40 #2, located in Monona, Iowa, is a local government-owned earth dam designed by USDA NRCS and completed in 1966. With a height of 38 feet and a length of 928 feet, this dam serves multiple purposes including fire protection, stock, small fish pond, and flood risk reduction. It has a storage capacity of 92 acre-feet and covers a surface area of 4.6 acres, with a drainage area of 0.51 square miles.
Managed by the Iowa DNR, Cottonwood-Green Valley Subws 50+40 #2 has a low hazard potential and a moderate risk assessment rating of 3. The dam features an uncontrolled spillway and is primarily constructed with soil foundations. While the condition assessment is currently not rated, the dam is subject to state regulation, permitting, inspection, and enforcement. The risk management measures and emergency action plan status for this dam are currently not available, highlighting the importance of ongoing monitoring and maintenance for water resource and climate enthusiasts.
Overall, Cottonwood-Green Valley Subws 50+40 #2 plays a crucial role in water resource management in the area, providing essential services for fire protection, agriculture, and flood control. As part of the Rock Island District, this dam contributes to the conservation and preservation of water resources in Iowa, highlighting the collaborative efforts between local government agencies and federal partners like USDA NRCS. Monitoring the condition and risk assessment of this dam is essential for ensuring its continued functionality and safety in the face of changing climate patterns and water resource demands.
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 Cottonwood-Green Valley Subws 50+40 #2 -- 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 | → |
| West Fork Ditch At Hornick | 80 cfs | → |
| Soldier River At Pisgah | 125 cfs | → |
| Missouri River At Decatur | 26,300 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Cottonwood-Green Valley Subws 50+40 #2.
Boat launches
Campgrounds
Track Cottonwood-Green Valley Subws 50+40 #2 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 Cottonwood-Green Valley Subws 50+40 #2
Where does the data for Cottonwood-Green Valley Subws 50+40 #2 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 Cottonwood-Green Valley Subws 50+40 #2.