Prairie State Energy Raw Water Dam Reservoir Report
Last Updated: December 21, 2025
Located in Marissa, Illinois, the Prairie State Energy Raw Water Dam, also known as Prairie State Energy/Marissa/Pond 2 Dam, was completed in 2010 by URS Corporation.
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Summary
This earth dam stands at a height of 39.5 feet and serves primarily as a water supply structure, with a storage capacity of 2422 acre-feet and a surface area of 0.11 square miles. The dam is regulated by the Illinois Department of Natural Resources and undergoes regular inspections for safety and compliance.
With a high hazard potential and risk assessment rating of 2, the Prairie State Energy Raw Water Dam is considered a critical infrastructure for water resource management in the region. It is designed to withstand the perched river or stream conditions in the area and has a stone core and soil foundation. While the dam does not have a spillway, its purpose is to ensure a reliable water supply for the surrounding community. The dam's emergency action plan was last revised in August 2017, highlighting the importance of preparedness in the face of potential risks and emergencies.
As a key component of the water supply infrastructure in Washington County, Illinois, the Prairie State Energy Raw Water Dam plays a crucial role in managing water resources and ensuring a sustainable supply for the local area. Its construction and design reflect the collaborative efforts of public utilities and regulatory agencies to uphold safety standards and protect the environment. With its strategic location and high hazard potential, the dam represents a vital asset in the region's resilience against climate change impacts and water resource challenges.
Year Completed |
2010 |
Dam Length |
6900 |
Dam Height |
39.5 |
River Or Stream |
PERCHED |
Primary Dam Type |
Earth |
Surface Area |
0.11 |
Drainage Area |
0.11 |
Nid Storage |
2422 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
40 |
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.
Prairie State Energy Raw Water Dam