The Fox River Navigational System Authority (FRNSA) wants to construct an electric barrier and water velocity system at the Menasha Lock to stop the spread of invasive species into the Lake Winnebago watershed, allowing the lock to reopen.
The FRNSA submitted its proposal to the Wisconsin Department of Natural Resources, which will need to approve it. The Menasha Lock has been closed since September 2015, when the Wisconsin DNR asked FRNSA to close the lock to prevent the spread of the round goby.
FRNSA’s barrier plan was developed with input from fish researchers, the U.S. Geological Survey and an independent fisheries management firm. The estimated cost is $3 million.
The plan calls for building a 100-foot-long concrete channel, 36 feet wide with vertical walls approximately 13 feet high (an estimated 2 inches will be visible above the waterline). Electrodes will be recessed in the concrete to create a pulsed DC electrical field.
The plan calls for installing a generator to use as a backup for the system. The system also uses changes in water velocity when the locks are opened to flush the lock channel, thus clearing out any invasive species that may be present in the channel. A portion of the riverbank on each side of the channel will be filled in to support the concrete channel.
The proposed barrier is not dangerous to humans and will allow boat traffic to safely proceed through the channel while preventing the migration of fish. A similar barrier is in use at the Chicago Sanitary and Ship Canal to prevent the spread of Asian carp into the Great Lakes.
DNR representatives will review the proposal and present any concerns to FRNSA.