Heritage Lake Dam

Heritage Lake Dam is an earth dam located in Tazewell County, Illinois, built in 1968. It carries a Significant hazard potential classification.

About Heritage Lake Dam

The primary purpose of Heritage Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Heritage Lake Association, Inc. (private). It impounds the Trib Mackinaw River near Mackinaw.

The dam stands 56 feet tall and stretches 590 feet across, creates a reservoir covering 78 acres, has a maximum storage capacity of 2,425 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1968, the structure is well into its service life at over 50 years old.

This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. An emergency action plan is in place for this dam. The most recent inspection on record was 11/22/2024.

At 56 feet, this dam is taller than 94% of dams nationwide.

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Significant HazardNot Available ConditionEmergency Action Plan: Yes

Location

StateIllinois
CountyTazewell
Nearest CityMackinaw
River/StreamTrib Mackinaw River
Coordinates40.54735, -89.34117

Physical Characteristics

Dam TypeEarth
NID Height56 ft
Dam Height56 ft
Dam Length590 ft
Year Completed1968 (58 years old)

Storage & Hydraulics

NID Storage2,425 acre-ft
Max Storage2,425 acre-ft
Normal Storage1,703 acre-ft
Surface Area78 acres
Drainage Area1 sq mi
Max Discharge1,820 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeRecreation
OwnerHERITAGE LAKE ASSOCIATION, INC.
Owner TypePrivate
Hazard ClassificationSignificant
Condition AssessmentNot Available
Last Inspection11/22/2024
Emergency Action PlanYes

Identifiers

NID IDIL00346
Federal IDIL00346
More InfoState Dam Safety Program

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