Pearl City Lagoon Dam Reservoir Report
Last Updated: December 13, 2025
Located in Pearl City, Illinois, the Pearl City Lagoon Dam is a local government-owned structure that serves as a crucial water resource for the area.
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Summary
Completed in 1970, this earth dam stands at a height of 11 feet and has a length of 1700 feet, providing a maximum storage capacity of 16 acre-feet. The dam is regulated by the Illinois Department of Natural Resources (IDNR) and undergoes regular inspections to ensure its safety and functionality.
The primary purpose of the Pearl City Lagoon Dam is classified as "Other", with a spillway type of "Uncontrolled". The dam poses a significant hazard potential and is rated as having a moderate risk level. While the condition assessment is currently listed as "Not Available", the dam is subject to inspection every three years to monitor its structural integrity. In case of emergencies, an Emergency Action Plan (EAP) may be implemented, although details on its preparation and guidelines adherence are not provided in the data.
With its location along the Yellow Creek offstream, the Pearl City Lagoon Dam plays a crucial role in managing water resources in Stephenson County, Illinois. Climate and water resource enthusiasts can appreciate this structure as a key component of the local ecosystem, supporting water storage and management efforts in the region.
Year Completed |
1970 |
Dam Length |
1700 |
Dam Height |
11 |
River Or Stream |
YELLOW CREEK - OFFSTREAM |
Primary Dam Type |
Earth |
Drainage Area |
0.1 |
Nid Storage |
16 |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
11 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Pecatonica River At Freeport
|
723cfs |
Pecatonica River At Martintown
|
473cfs |
Apple River Near Hanover
|
110cfs |
Elkhorn Creek Near Penrose
|
44cfs |
Rock River At Byron
|
4300cfs |
Pecatonica River At Darlington
|
218cfs |
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.
Pearl City Lagoon Dam