Mill Creek Structure 8 Dam Reservoir Report
Last Updated: December 22, 2025
Mill Creek Structure 8 Dam, located in Snyder, Illinois, was completed in 1987 by the USDA NRCS and serves as a crucial flood risk reduction measure along the Blackburn Branch river.
°F
°F
mph
Wind
%
Humidity
Summary
This private-owned earth dam stands at a height of 40 feet and spans 650 feet in length, with a storage capacity of 3,219 acre-feet. The dam features an uncontrolled spillway with a width of 208 feet, designed to handle a maximum discharge of 6,528 cubic feet per second.
Managed by the Illinois Department of Natural Resources, this dam is regulated, inspected, and enforced by state authorities to ensure its structural integrity and safety standards. Despite being classified with a low hazard potential, the risk assessment for Mill Creek Structure 8 Dam indicates a moderate level of risk (3). With its primary purpose being flood risk reduction, this dam plays a crucial role in protecting the surrounding area from potential flooding events, showcasing the importance of sustainable water resource management practices in mitigating climate-related risks.
Year Completed |
1987 |
Dam Length |
650 |
Dam Height |
40 |
River Or Stream |
BLACKBURN BRANCH |
Primary Dam Type |
Earth |
Drainage Area |
6.1 |
Nid Storage |
3219 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
40 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Wabash River At Terre Haute
|
2380cfs |
Wabash River At Riverton Ind
|
2610cfs |
North Fork Embarras River Near Oblong
|
53cfs |
Busseron Creek Near Carlisle
|
138cfs |
Embarras River At Ste. Marie
|
65cfs |
Big Raccoon Creek At Coxville
|
100cfs |
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.
Mill Creek Structure 8 Dam