Eau Pleine

Eau Pleine is a gravity dam located in Marathon County, Wisconsin, built in 1937. It carries a High hazard potential classification and has a fair condition assessment.

About Eau Pleine

The primary purpose of Eau Pleine is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Wisconsin Valley Improvement Company (public utility). It impounds the Big Eau Pleine River near Stevens Point.

The dam stands 45 feet tall and stretches 8,599 feet across, creates a reservoir covering 6,677 acres, has a maximum storage capacity of 98,140 acre-feet, and collects water from a drainage area of 370 square miles. Completed in 1937, the structure is well-established, with more than 75 years of service.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 08/01/2022.

At 45 feet, this dam is taller than 91% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Wisconsin dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateWisconsin
CountyMarathon
Nearest CityStevens Point
River/StreamBig Eau Pleine River
Coordinates44.73080, -89.75930

Physical Characteristics

Dam TypeGravity
NID Height45 ft
Dam Height45 ft
Dam Length8,599 ft
Year Completed1937 (89 years old)

Storage & Hydraulics

NID Storage98,140 acre-ft
Max Storage98,140 acre-ft
Normal Storage98,140 acre-ft
Surface Area6,677 acres
Drainage Area370 sq mi
Max Discharge20,767 cfs
Spillway TypeControlled

Ownership & Safety

PurposeHydroelectric
OwnerWisconsin Valley Improvement Company
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection08/01/2022
Emergency Action PlanYes

Identifiers

NID IDWI00753
Federal IDWI00753
More InfoState Dam Safety Program

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