Incidental Take Public Notice:

Proposed STH 108 Bridge Replacement

Proposed Incidental Take Authorization of the state threatened Buckhorn Mussel (Tritogonia verrucosa) from Causeway Construction at the STH 108 Bridge Replacement over the LaCrosse River, LaCrosse County, Wisconsin.

The Department of Natural Resources proposes to authorize the Wisconsin Department of Transportation (WDOT) for the "incidental taking" of the state threatened Buckhorn mussel (Tritogonia verrucosa) resulting from causeway construction necessary to replace and remove the existing STH 108 bridge over the LaCrosse River. "Take" is the destruction or possession of an endangered or threatened animal, or in some cases, of an endangered or threatened plant from public lands.

The existing STH 108 bridge over the LaCrosse River will have to be removed prior to the construction of the new bridge. The WDOT needs to build a temporary causeway to remove the existing bridge deck and piers. The causeway will be removed upon completion of the old bridge removal. A single State-threatened Buckhorn mussel was found at the bridge site in 1999. However, the site's aquatic habitat is of poor quality and contains only a small number of common mussels that do not represent a diverse or abundant mussel assemblage. No other individuals of this species, nor any other state or federally listed species, are known to occur at the site.

The causeway will result in temporary fill in the LaCrosse River, which will be constructed in accordance with state and federal regulations. The placement of stone for the causeway at the site may result in the incidental taking of the State-threatened Buckhorn mussel. The Department has determined that efforts were made to minimize impacts to the species; the taking is not likely to jeopardize the continued existence and recovery of state populations of the Buckhorn mussel or the whole plant-animal community of which it is a part; and the action has benefit to the public safety that justifies the action. The public notice period is being expedited because the occurrence of the Buckhorn mussel at this site was reported late in the project's permit review process and the anticipated impact to the listed species is very low. WDOT is holding construction until the project is authorized.

Copies of the jeopardy assessment and conservation measures are available below or upon request from:

Information & Supporting Materials:
Jeopardy Assessment and Background Information [PDF 73KB]