Stonehenge Lake Dam

PRAIRIE DU LONG CREEK· St. Clair, Illinois· Built 2008· Earth· 33 ft tall
Significant Hazard Recreation Private

Key Takeaway

Stonehenge Lake Dam is classified as significant hazard in Illinois. It was completed in 2008 and is 18 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 33 ft (taller than 71.6% in IL)
Dam Length320 ft
Dam TypeEarth
Max Storage200 acre-ft
Normal Storage95 acre-ft
Surface Area18 acres
Drainage Area4 sq mi
Max Discharge2,846 cfs
Year Completed2008 (18 years old)
NID IDIL50575

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: Yes
Last Inspection: June 8, 2018
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

STONEHENGE LAND TRUST II

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Stonehenge Lake Dam?

Stonehenge Lake Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Stonehenge Lake Dam?

Stonehenge Lake Dam is owned by STONEHENGE LAND TRUST II (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Stonehenge Lake Dam built?

Stonehenge Lake Dam was completed in 2008, making it 18 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 Stonehenge Lake Dam?

Stonehenge 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 Stonehenge Lake Dam?

Stonehenge Lake Dam has a dam height of 33 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 Stonehenge Lake Dam last inspected?

Stonehenge Lake Dam was last inspected on June 8, 2018. 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.