Patterson Dam dam
Patterson Dam
Patterson Dam, located in Indianola, Iowa, is a privately owned structure designed by USDA NRCS and completed in 2018 for grade stabilization purposes. The dam stands at a height of 32 feet and spans a length of 447 feet, with a storage capacity of 57 acre-feet and a surface area of 4 acres. It serves multiple purposes, including grade stabilization, recreation, and water supply for the surrounding area.
Managed by the Iowa DNR and regulated by the state, Patterson Dam has a low hazard potential and is currently not rated for its condition assessment. Despite its moderate risk level, the dam has not been modified since completion, and its emergency action plan status and risk management measures remain unreported. With a spillway width of 20 feet and uncontrolled outlet gates, the dam plays a crucial role in managing water resources in the region and ensuring the safety of downstream communities in the event of a flood or emergency situation.
As a key infrastructure in the tributary to Squaw Creek, Patterson Dam contributes to the overall resilience of the water management system in Clarke County, Iowa. With its strategic location and design, the dam plays a vital role in mitigating erosion, providing recreational opportunities, and supporting water supply needs. Continuous monitoring and maintenance efforts are essential to ensure the long-term effectiveness and safety of Patterson Dam for both water resource and climate enthusiasts in the region.
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 Patterson Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| South River Near Ackworth | 1,990 cfs | → |
| Middle River Near Indianola | 1,120 cfs | → |
| North River Near Norwalk | 1,200 cfs | → |
| Raccoon River Near West Des Moines | 1,320 cfs | → |
| Raccoon River At Van Meter | 2,980 cfs | → |
| White Breast Creek Near Dallas | 3,200 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Patterson Dam.
Boat launches
- Us 34 Clarke County
- Pershing Street Warren County
- 118th Avenue Warren County
- 120th Street Madison County
- 360th Street Dallas County
- Walnut Woods Drive West Des Moines
Track Patterson 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 Patterson Dam
Where does the data for Patterson 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 Patterson Dam.