Mason City-Lehigh Cement Milldam dam
Mason City-Lehigh Cement Milldam
The Mason City-Lehigh Cement Milldam is a historic structure located in Cerro Gordo County, Iowa, along the Calmus Creek. Built in 1924, this gravity dam serves as a vital water supply source for the area, with a storage capacity of 150 acre-feet and a normal storage level of 75 acre-feet. The dam has a height of 8 feet and a length of 71 feet, helping to regulate the flow of water and maintain a surface area of 20 acres.
Managed by a private owner, the Mason City-Lehigh Cement Milldam is regulated by the Iowa Department of Natural Resources and undergoes regular inspections to ensure its structural integrity and safety. Despite its low hazard potential, the dam is classified as having a moderate risk level due to its age and lack of recent condition assessments. While the dam's spillway type is listed as uncontrolled, the risk management measures and emergency action plans for the structure are currently not rated or prepared.
For water resource and climate enthusiasts, the Mason City-Lehigh Cement Milldam represents a piece of Iowa's water infrastructure history. With its unique design and role in providing water supply, this gravity dam serves as a reminder of the importance of maintaining and monitoring our water resources to ensure safety and sustainability for future generations.
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 Mason City-Lehigh Cement Milldam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Winnebago River At Mason City | 501 cfs | → |
| Cedar River At Charles City | 627 cfs | → |
| Cedar River Near Austin | 173 cfs | → |
| Iowa River Near Rowan | 364 cfs | → |
| Little Cedar River Near Ionia | 159 cfs | → |
| Shell Rock River At Shell Rock | 1,740 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mason City-Lehigh Cement Milldam.
Boat launches
- South Pierce Avenue Mason City
- Big Blue Loop Mason City
- Main Avenue Clear Lake
- Nelson Street Cerro Gordo County
- East Lake Street Ventura
- Finch Avenue Worth County
Track Mason City-Lehigh Cement Milldam 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 Mason City-Lehigh Cement Milldam
Where does the data for Mason City-Lehigh Cement Milldam 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 Mason City-Lehigh Cement Milldam.