Menasha Lock Updates


Our goal is to reopen the Menasha Lock, but not without a solution that prevents the invasive round goby from entering the waters of Lake Winnebago. To that end, we have been working with a firm to study the effects of an electronic barrier and water velocity on deterring the fish from entering the lock channel.

The current plan calls for building an electric array near the bottom of the Menasha lock channel that would pulse and push the gobies away or immobilize them.

Closing the Menasha lock, the background

The Menasha lock was closed in 2015 due to the discovery of the round goby, an invasive fish species populating the Great Lakes. In order to keep these fish from reaching the Lake Winnebago system, the DNR requested the lock closure, and the Fox River Navigational Authority (FRNSA) complied.

Over the years we have worked with fish researchers, engineers, and an independent fisheries management firm to review the most recent scientific research on invasive species barriers and solutions that have worked for other communities in the Great Lakes region. We have invested about $200,000 to research the behaviors of the round goby and design concepts to do three things:

  • Prevent the spread of the round goby into the Lake Winnebago watershed,
  • Return the Menasha lock to operation,
  • Build a system that can be adapted to prevent the spread of any future invasive species.

Working with experts in aquatic ecosystem management, we designed a plan using a system of an electric deterrent barrier and water flow regulation at the Menasha lock to stop the spread of the round goby.


Closing the Menasha lock, the proposed plan

The concept is 60% designed and involves building a concrete, U-shaped channel adjacent to and downstream from the Menasha lock. Electrodes would be recessed in the bottom of the channel. This type of a barrier will allow boat traffic to pass through the channel while halting the passage of fish. The barrier delivers a pulsing DC current to fish entering the channel, causing them to turn around and not enter the lock; it also uses a water velocity process to prevent the round goby from moving into the lock channel. The DC current in the water is a slower pulse at a lower frequency, so this is nothing like the electrical current that you might have in your home.

Based on issues raised by the Wisconsin DNR, biologists at Kleinschmidt conducted a series of experiments on round goby and their reactions to an electric field in the water column. The research confirmed these changes:

  • Experiments found that higher voltage gradients were needed to immobilize smaller gobies. As a result, the voltage gradients were increased to 1.2 V/cm from 1.0 V/cm.
  • Experiments found that a faster wave frequency was needed to immobilize round gobies. As a result, the frequency was increased to 20 Hertz from 10 Hertz. (Frequency is the rate at which current changes direction per second. It is measured in hertz (Hz), where 1 hertz is equal to 1 cycle per second.)

Other changes made outside of lab experiments:

  • The electric field was extended throughout the water column outside the Menasha lock, rather than only the bottom 1-foot of water depth.
  • Changes were made in the location of electrodes and electrical connections within and around the concrete channel outside of the lock.
  • The plan recommends a pre-lockage flush of water in the lock chamber, moving water from Lake Winnebago to the Fox River.
  • The plan will not allow non-motorized boats and personal watercraft to cross the electric deterrent system. These crafts will have to portage the Menasha lock.
  • The plan itemizes safety policies to protect all boaters and staff while crossing the electric deterrent system or while inside the lock.

The Authority completed a plan that was submitted to the DNR for review and comment. The primary portions of the documents are available for public review.

A report on the design of the electric barrier is at this link
A report showing the design of the electric barrier at 60% completion is at this link
A report of construction materials specifications is at this link
An operating manual for the system is at this link.

The plan and supporting studies and documentation was originally presented to the DNR in October of 2018. Copies of that report may be found at this link: Part 1, Part 2. At that time, the DNR had several questions posed to researchers and fish management experts. FRNSA commissioned further research on these topics that include:

A comprehensive review of the round goby available at this link
A review of the behavior of the electric field used in the barrier available at this link
A report on electrical conductivity in varying water conditions available at this link
A comprehensive report on the electric barriers currently in operation available at this link

If you have questions about the barrier or any plans, please use our contact form.