Maas Dam Reservoir Report
Last Updated: December 18, 2025
Maas Dam, located in Ellisville, Illinois, is a privately owned earth dam constructed in 1999 for recreation purposes.
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Summary
The dam stands at a height of 60 feet and spans 700 feet, with a storage capacity of 195 acre-feet. Situated on the TRIB LITTLE COAL CREEK, the dam serves as a recreational spot with a surface area of 7.9 acres and a maximum discharge capacity of 480 cubic feet per second.
Managed by the Illinois Department of Natural Resources (IDNR), Maas Dam is regulated, permitted, inspected, and enforced by the state agency to ensure compliance and safety. Despite its low hazard potential, the dam's risk assessment is moderate, indicating the need for ongoing risk management measures. While the condition assessment is not available, regular inspections are conducted every five years, with the last inspection taking place in April 2021.
With its scenic location and recreational opportunities, Maas Dam provides a valuable resource for water and climate enthusiasts in Fulton, Illinois. As a well-maintained earth dam with a controlled spillway, the dam offers a safe and enjoyable environment for visitors to appreciate the beauty of the surrounding area and engage in various water-based activities.
Year Completed |
1999 |
Dam Length |
700 |
Dam Height |
60 |
River Or Stream |
TRIB LITTLE COAL CREEK |
Primary Dam Type |
Earth |
Surface Area |
7.9 |
Drainage Area |
0.09 |
Nid Storage |
195 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Rock, Soil |
Nid Height |
60 |
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.
Maas Dam