Phillips Subwatershed Site M-17312 Reservoir Report
Last Updated: December 13, 2025
Phillips Subwatershed Site M-17312 in Monona County, Iowa, is a local government-owned earth dam completed in 1956 by the USDA NRCS for fire protection, stock, or small fish pond purposes.
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Summary
The dam has a height of 38 feet and a storage capacity of 188 acre-feet, serving to reduce flood risks in the area. Situated on TR-MAPLE RIVER, the dam is regulated by the Iowa DNR and is subject to state permitting, inspection, and enforcement.
With a drainage area of 2.56 square miles and a low hazard potential, Phillips Subwatershed Site M-17312 poses a moderate risk with a risk assessment rating of 3. While the condition assessment is not rated and the emergency action plan status is unknown, the dam's design and construction by the NRCS ensure its structural integrity. The dam does not have a spillway and is not owned or funded by federal agencies, highlighting its local government ownership and management for water resource and climate enthusiasts to monitor and support.
Year Completed |
1956 |
Dam Height |
38 |
River Or Stream |
TR-MAPLE RIVER |
Primary Dam Type |
Earth |
Drainage Area |
2.56 |
Nid Storage |
188 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
38 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Maple River At Mapleton
|
323cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
West Fork Ditch At Hornick
|
80cfs |
Soldier River At Pisgah
|
112cfs |
Missouri River At Decatur
|
15500cfs |
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.
Phillips Subwatershed Site M-17312