Lake In The Hills 2 Dam Reservoir Report
Last Updated: December 13, 2025
Lake In The Hills 2 Dam, located in McHenry, Illinois, serves as a critical infrastructure for water resource and climate management in the region.
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Summary
Built in 1947, this earth dam stands at a height of 15 feet and stretches 635 feet in length along Crystal Creek. With a storage capacity of 125 acre-feet and a drainage area of 1.8 square miles, the dam plays a key role in flood control and water supply for the surrounding community.
Managed by the local government and regulated by the Illinois Department of Natural Resources, Lake In The Hills 2 Dam is designed for recreational purposes in addition to its primary function. The dam's spillway, with a width of 40 feet, helps to control the flow of water during periods of high discharge, ensuring the safety and stability of the structure. Despite being classified as having a significant hazard potential, the dam is regularly inspected and maintained to meet safety standards and mitigate risks to the surrounding area.
With no associated locks or outlet gates, Lake In The Hills 2 Dam relies on its design and construction to effectively manage water levels and prevent potential disasters. The dam's moderate risk assessment highlights the importance of ongoing monitoring and risk management measures to safeguard the community and the environment. As a vital component of the region's water infrastructure, Lake In The Hills 2 Dam demonstrates the intersection of water resource management and climate resilience in the face of changing environmental conditions.
Year Completed |
1947 |
Dam Length |
635 |
Dam Height |
15 |
River Or Stream |
CRYSTAL CREEK |
Primary Dam Type |
Earth |
Surface Area |
130 |
Drainage Area |
1.8 |
Nid Storage |
125 |
Outlet Gates |
None |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Fox River At Algonquin
|
725cfs |
Fox River At Algonquin (Tailwater)
|
644cfs |
Tyler Creek At Elgin
|
8cfs |
Boone Creek Near Mc Henry
|
10cfs |
Poplar Creek At Elgin
|
7cfs |
Fox River At South Elgin
|
759cfs |
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.
Lake In The Hills 2 Dam
Hilltop Drive 145, Lake in the Hills