Mason Dam dam
Mason Dam
Mason Dam, located in Jasper County, Iowa, was completed in 1963 and is owned by a private entity. The dam, with a height of 22 feet and a length of 526 feet, serves multiple purposes including fire protection and creating a small fish pond. Its primary source agency is the Iowa Department of Natural Resources, and it is regulated and inspected by state authorities. The dam has a storage capacity of 91 acre-feet and covers a surface area of 7.5 acres, with a drainage area of 0.56 square miles.
Managed by the USDA NRCS, Mason Dam is primarily an earth dam with a soil foundation. It has a low hazard potential and is classified as being in moderate risk. The spillway type is uncontrolled, and there are no outlet gates or associated structures. While the dam's condition assessment is not rated and it has not been inspected since October 1964, it meets state regulatory requirements and is considered to be in compliance with enforcement measures. Despite its age, Mason Dam continues to serve its intended purposes effectively and safely for the surrounding environment and community.
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 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 | → |
| South Skunk River At Colfax | 631 cfs | → |
| Walnut Creek Near Hartwick | 35 cfs | → |
| Indian Creek Near Mingo | 211 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mason Dam.
Boat launches
- Rock Creek East Street Jasper County
- Jade Street Jasper County
- C Avenue Tama County
- Atv Trail Tama
- P Avenue Tama County
- Arney Avenue Marshall County
Track Mason 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 Mason Dam
Where does the data for Mason 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 Mason Dam.