Long Lake

Long Lake is a gravity dam located in Washburn County, Wisconsin, built in 1913. It carries a High hazard potential classification and has a fair condition assessment.

About Long Lake

The primary purpose of Long Lake is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Washburn County (local government). It impounds the Brill near Brill.

The dam stands 15 feet tall and stretches 575 feet across, creates a reservoir covering 3,290 acres, has a maximum storage capacity of 35,000 acre-feet, and collects water from a drainage area of 82 square miles. Completed in 1913, 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 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 05/07/2020.

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
CountyWashburn
Nearest CityBrill
River/StreamBrill
Coordinates45.66801, -91.68066

Physical Characteristics

Dam TypeGravity
NID Height15 ft
Dam Height15 ft
Dam Length575 ft
Year Completed1913 (113 years old)

Storage & Hydraulics

NID Storage35,000 acre-ft
Max Storage35,000 acre-ft
Normal Storage15,000 acre-ft
Surface Area3,290 acres
Drainage Area82 sq mi
Max Discharge2,660 cfs
Spillway TypeControlled

Ownership & Safety

PurposeRecreation
OwnerWashburn County
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection05/07/2020
Emergency Action PlanYes

Identifiers

NID IDWI00325
Federal IDWI00325
More InfoState Dam Safety Program

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