East Fork Grand River Watershed Site A-31 Reservoir Report
Last Updated: December 13, 2025
Located in Union, Iowa, East Fork Grand River Watershed Site A-31 is a flood risk reduction structure designed by the USDA NRCS and completed in 2005.
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Summary
This earth dam stands at a height of 21 feet and stretches 675 feet in length, with a storage capacity of 79 acre-feet. Situated on TR- Squaw Creek, this site is regulated by the Iowa DNR and is subject to state permitting, inspection, and enforcement.
With a low hazard potential and a moderate risk assessment rating, East Fork Grand River Watershed Site A-31 plays a crucial role in managing flood risk in the area. The dam has not been rated for its condition assessment, but it meets state regulatory requirements for operation and maintenance. Despite its uncontrolled spillway type, the structure has proven effective in reducing the risk of flooding in the region.
For water resource and climate enthusiasts, East Fork Grand River Watershed Site A-31 offers a fascinating glimpse into the intersection of infrastructure and environmental conservation. As part of the broader efforts to mitigate flood risks and protect local communities, this structure stands as a testament to the importance of sustainable water management practices. Its location in the Rock Island District and its association with the Natural Resources Conservation Service highlight the collaborative efforts involved in safeguarding our water resources for future generations.
Year Completed |
2005 |
Dam Length |
675 |
Dam Height |
21 |
River Or Stream |
TR- SQUAW CREEK |
Primary Dam Type |
Earth |
Surface Area |
4.7 |
Drainage Area |
0.22 |
Nid Storage |
79 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
21 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
East Fork Grand River Watershed Site A-31