Greene Mill Dam dam
Greene Mill Dam
Greene Mill Dam, located in Greene, Iowa along the Shell Rock River, is a historic gravity dam that was completed in 1925 for hydroelectric purposes. With a height of 10.67 feet and a length of 282 feet, the dam has a normal storage capacity of 385 acre-feet and serves as a vital water resource in the region. Managed by a private owner, the dam is regulated by both state and federal agencies, including the Iowa Department of Natural Resources and the Federal Energy Regulatory Commission.
Despite its age, Greene Mill Dam has a low hazard potential and is considered to be in moderate risk condition. With an uncontrolled spillway and a maximum discharge capacity, the dam plays a crucial role in managing water flow and storage in the area. Regular inspections are conducted by regulatory agencies to ensure the structural integrity and safety of the dam, with the most recent inspection taking place in July 2018. Additionally, emergency action plans are in place to mitigate any potential risks and ensure the protection of downstream communities in case of a dam failure.
Overall, Greene Mill Dam stands as a testament to early 20th-century engineering and continues to contribute to the region's water resource management and hydroelectric power generation. As an integral part of the Shell Rock River watershed, the dam's historical significance and functional importance make it a focal point for water resource and climate enthusiasts interested in sustainable infrastructure development and management.
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 Greene Mill Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cedar River At Charles City | 531 cfs | → |
| Shell Rock River At Shell Rock | 1,240 cfs | → |
| Little Cedar River Near Ionia | 232 cfs | → |
| Cedar River At Waverly | 1,650 cfs | → |
| West Fork Cedar River At Finchford | 539 cfs | → |
| Cedar River At Janesville | 1,440 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Greene Mill Dam .
Boat launches
- 245th Street Butler County
- 140th Street Bremer County
- Atlas Avenue Bremer County
- Adams Parkway Waverly
- Finchford Road Black Hawk County
- Big Blue Loop Mason City
Campgrounds
- Cedar View Park Campground
- North Cedar Park
- Shell Rock Rec Area
- Cedar Bend Park
- West Idlewild County Park
- Colwell County Park Camping
Paddle runs
Track Greene Mill 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 Greene Mill Dam
Where does the data for Greene Mill 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 Greene Mill Dam .