East Fork Grand River Watershed Site D-66 Reservoir Report
Last Updated: December 12, 2025
East Fork Grand River Watershed Site D-66 is a local government-owned flood risk reduction structure located in Ringgold County, Iowa.
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Summary
Designed by the USDA NRCS and regulated by the Iowa DNR, this Earth-type dam stands at 23 feet tall and spans 630 feet in length. Completed in 2008, it serves the primary purpose of flood risk reduction for the tributary of Lotts Creek, with a capacity to store 91 acre-feet of water and covering a surface area of 3.9 acres.
With a low hazard potential and a moderate risk assessment rating, this dam has not been rated for its condition assessment. Despite not having a designated emergency action plan or updated contact information, the structure meets state permitting and inspection requirements. The site's spillway is uncontrolled, with a width of 1 foot, and there are no associated locks or outlet gates. While the dam has not been modified in recent years, it continues to serve its crucial function in mitigating flood risks in the area.
Water resource and climate enthusiasts would find East Fork Grand River Watershed Site D-66 to be an intriguing example of a locally-managed flood control infrastructure in the heart of Iowa. Its location, design, and purpose offer valuable insights into the collaborative efforts between federal agencies like the USDA NRCS and state regulators like the Iowa DNR. As a vital component of the region's water management system, this dam plays a significant role in safeguarding the surrounding communities from potential flood threats.
Year Completed |
2008 |
Dam Length |
630 |
Dam Height |
23 |
River Or Stream |
Trib to Lotts Creek |
Primary Dam Type |
Earth |
Surface Area |
3.9 |
Drainage Area |
0.28 |
Nid Storage |
91 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
23 |
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 D-66