Stratton Lock And Dam Reservoir Report

Last Updated: December 5, 2025

Stratton Lock and Dam, also known as McHenry Lock and Dam, is a state-owned structure located in Holiday Hills, Illinois, along the Fox River.


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Summary

Completed in 1939, this gravity dam stands at a height of 7 feet and stretches 275 feet in length, serving primarily for flood risk reduction purposes. With a storage capacity of 113,000 acre-feet, the dam plays a crucial role in regulating water levels and protecting surrounding areas from potential flooding events.

Managed by the Illinois Department of Natural Resources, the dam features a controlled spillway with a width of 627 feet and five slide gates for water release. The facility is subject to regular inspections, with a hazard potential rated as significant and a risk assessment indicating a very high risk level. Despite limited information on its condition assessment, the dam remains operational and plays a vital role in water resource management and flood control efforts within the region.

In addition to flood risk reduction, the Stratton Lock and Dam also offers recreational opportunities, making it a valuable asset for both water resource management and community engagement. Situated in McHenry County, Illinois, the dam's strategic location along the Fox River underscores its importance in maintaining water quality, managing drainage areas, and safeguarding against potential risks associated with high water discharge levels. As a key infrastructure element in the region, the dam serves as a critical component in ensuring the safety and sustainability of water resources for both present and future generations of residents and visitors alike.

Year Completed

1939

Dam Length

275

Dam Height

7

River Or Stream

FOX RIVER

Primary Dam Type

Gravity

Surface Area

8700

Drainage Area

1243

Nid Storage

113000

Outlet Gates

Slide (sluice gate) - 5

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

7
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.