Lake Thunderhawk Dam

LITTLE SALINE RIVER· Johnson, Illinois· Built 1975· Earth· 31 ft tall
Low Hazard Recreation Private

Key Takeaway

Lake Thunderhawk Dam is classified as low hazard in Illinois. It was completed in 1975 and is 51 years old. Its primary use is recreation.

Physical Details

Dam Height 31 ft (taller than 66.2% in IL)
Dam Length490 ft
Dam TypeEarth
Max Storage383 acre-ft
Normal Storage232 acre-ft
Year Completed1975 (51 years old)
NID IDIL00957

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: April 19, 2023
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

FRNAK NUTTY

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Thunderhawk Dam?

Lake Thunderhawk 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 Lake Thunderhawk Dam?

Lake Thunderhawk Dam is owned by FRNAK NUTTY (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lake Thunderhawk Dam built?

Lake Thunderhawk Dam was completed in 1975, making it 51 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 Lake Thunderhawk Dam?

Lake Thunderhawk 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 Lake Thunderhawk Dam?

Lake Thunderhawk Dam has a dam height of 31 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 Lake Thunderhawk Dam last inspected?

Lake Thunderhawk Dam was last inspected on April 19, 2023. 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.