Island Lake Dam

COTTON CREEK· McHenry, Illinois· Built 1940· Earth· 12 ft tall
Low Hazard Recreation Local Government

Key Takeaway

Island Lake Dam is classified as low hazard in Illinois. It was completed in 1940 and is 86 years old. Its primary use is recreation.

Physical Details

Dam Height 12 ft (taller than 10% in IL)
Dam Length160 ft
Dam TypeEarth
Max Storage470 acre-ft
Normal Storage373 acre-ft
Year Completed1940 (86 years old)
NID IDIL00580

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: May 25, 2022
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

VILLAGE OF ISLAND LAKE

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Island Lake Dam?

Island Lake Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Island Lake Dam?

Island Lake Dam is owned by VILLAGE OF ISLAND LAKE (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Island Lake Dam built?

Island Lake Dam was completed in 1940, making it 86 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Island Lake Dam?

Island Lake Dam serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Island Lake Dam?

Island Lake Dam has a dam height of 12 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Island Lake Dam last inspected?

Island Lake Dam was last inspected on May 25, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.