Patterson Dam Reservoir Report
Nearby: Oswald Dam High Prairie Farms Dam
Last Updated: December 10, 2025
Patterson Dam, located in Clarke County, Iowa, was completed in 1994 by the USDA NRCS and serves multiple purposes including fire protection, stock, and small fish pond.
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Summary
The earth dam stands at 26 feet high and stretches 380 feet in length, with a storage capacity of 55 acre-feet. The dam is situated on TR- Squaw Creek and is owned and regulated by a private entity, with oversight from the Iowa DNR.
Despite its low hazard potential, Patterson Dam is subject to moderate risk due to its location and potential impact on downstream areas. The dam has not been rated for its condition, and there is no recent inspection data available. While the dam does not have a controlled spillway, it is equipped with uncontrolled spillway type. The surrounding area covers 4.2 acres with a drainage area of 0.18 square miles.
Water resource and climate enthusiasts interested in Patterson Dam can appreciate its significant role in local water management and conservation efforts in Clarke County. With its multiple purposes and moderate risk level, the dam represents a valuable asset in the region's infrastructure. Initiatives to assess and improve the dam's condition, inspection frequency, and risk management measures can further enhance its resilience and longevity in safeguarding the surrounding community and environment.
Year Completed |
1994 |
Dam Length |
380 |
Dam Height |
26 |
River Or Stream |
TR- SQUAW CREEK |
Primary Dam Type |
Earth |
Surface Area |
4.2 |
Drainage Area |
0.18 |
Nid Storage |
55 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
26 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
South River Near Ackworth
|
18cfs |
Middle River Near Indianola
|
48cfs |
North River Near Norwalk
|
48cfs |
Raccoon River Near West Des Moines
|
1300cfs |
Raccoon River At Van Meter
|
1640cfs |
White Breast Creek Near Dallas
|
5cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
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. Investigations and studies are necessary.
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.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams 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, environment 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.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Patterson Dam