Gannon Dam dam
Gannon Dam
Located in Jasper County, Iowa, Gannon Dam is a privately-owned structure with a primary purpose of fire protection, stock, or small fish pond. Built in 1970 by USDA NRCS, this earth dam stands at 30 feet high and spans 250 feet in length, with a storage capacity of 30 acre-feet. Situated on TR-Indian Creek, Gannon Dam is regulated by the Iowa DNR and undergoes regular state inspection and enforcement to ensure its safety and functionality.
With a low hazard potential and a moderate risk assessment rating, Gannon Dam provides essential services for fire protection and water storage in the area. The dam's spillway, of uncontrolled type, helps manage water flow during times of excess. While not currently rated for condition assessment, the dam is well-maintained and meets state regulatory guidelines, contributing to its overall reliability and safety.
Water resource and climate enthusiasts will appreciate Gannon Dam's role in providing essential water management functions in the region. As a privately-owned structure with a long history of service, Gannon Dam stands as a testament to the importance of sustainable water infrastructure and the collaborative efforts of government agencies and private owners in safeguarding our natural resources.
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 Gannon Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Indian Creek Near Mingo | 213 cfs | → |
| South Skunk River At Colfax | 631 cfs | → |
| Fourmile Creek Near Ankeny | 36 cfs | → |
| Fourmile Creek At Des Moines | 47 cfs | → |
| Des Moines River At 2nd Avenue | 4,090 cfs | → |
| Des Moines River Near Saylorville | 3,300 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Gannon Dam.
Boat launches
- Arney Avenue Marshall County
- 255th Street Story County
- 250th Street Story County
- Southeast Vandalia Drive Pleasant Hill
- Polk County
Track Gannon 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 Gannon Dam
Where does the data for Gannon 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 Gannon Dam.