Twin Falls Auxiliary Dike

Twin Falls Auxiliary Dike is a gravity dam located in Florence County, Wisconsin, built in 1912. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Twin Falls Auxiliary Dike

The primary purpose of Twin Falls Auxiliary Dike 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 Electric Power Company (public utility). It impounds the Menominee River.

The dam stands 30 feet tall, creates a reservoir covering 960 acres, and has a maximum storage capacity of 9,750 acre-feet. Completed in 1912, the structure is over a century old.

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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 05/18/2022.

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 HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateWisconsin
CountyFlorence
River/StreamMenominee River
Coordinates45.87450, -88.07550

Physical Characteristics

Dam TypeGravity
NID Height30 ft
Dam Height30 ft
Year Completed1912 (114 years old)

Storage & Hydraulics

NID Storage9,750 acre-ft
Max Storage9,750 acre-ft
Normal Storage9,750 acre-ft
Surface Area960 acres
Max Discharge58,900 cfs

Ownership & Safety

PurposeHydroelectric
OwnerWisconsin Electric Power Company
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection05/18/2022
Emergency Action PlanYes

Identifiers

NID IDMI00143
Federal IDMI00143S002
More InfoState Dam Safety Program

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