Green Castle Dam dam
Green Castle Dam
Green Castle Dam, located in Marshall County, Iowa, is a local government-owned structure on the TR-Brush Creek that serves primarily for recreational purposes. Built in 1954 by CLAPSADDLE-GARBER, this earth dam stands at a height of 30 feet and spans 650 feet in length, with a storage capacity of 263 acre-feet. Despite its uncontrolled spillway type and significant hazard potential, the dam's condition assessment remains satisfactory as of the last inspection in June 2020.
With its location in Ferguson, Iowa, the Green Castle Dam offers a serene setting for water resource and climate enthusiasts to explore. The dam's stone core and soil foundation contribute to its structural integrity, while the surrounding area boasts a surface area of 17 acres and a drainage area of 0.44 square miles. While the dam has not undergone significant modifications over the years, it is subject to regular inspections by the Iowa Department of Natural Resources to ensure compliance with state regulations and enforcement.
In the event of emergencies, the dam's risk assessment is categorized as moderate, with a designated inspection frequency of 5 years. While an Emergency Action Plan (EAP) is not currently prepared, the dam's risk management measures aim to mitigate potential hazards and ensure public safety. Overall, Green Castle Dam stands as a vital recreational asset in the region, showcasing the intersection of water resource management and environmental stewardship.
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 Green Castle Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Timber Creek Near Marshalltown | 94 cfs | → |
| Iowa River At Marshalltown | 815 cfs | → |
| Richland Creek Near Haven | 38 cfs | → |
| Indian Creek Near Mingo | 211 cfs | → |
| Walnut Creek Near Hartwick | 35 cfs | → |
| South Skunk River At Colfax | 631 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Green Castle Dam.
Boat launches
- C Avenue Tama County
- Rock Creek East Street Jasper County
- Jade Street Jasper County
- Marsh Avenue Marshall County
- Atv Trail Tama
- Bb Avenue Tama County
Track Green Castle 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 Green Castle Dam
Where does the data for Green Castle 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 Significant 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 Green Castle Dam.