Conservationist warns dam decommissioning may speed downstream flows, Jersey Valley restoration uncertain

Ben Wojahn, Vernon County conservationist, told the Board the county has 22 PL-566 flood-control dams, two of which have breached, and that a $2,000,000 study is narrowing options to either retain the dams at county expense or proceed with decommissioning while pursuing federal funding.

Wojahn cautioned that removing dams can increase downstream velocity, saying, "yes, yes it will, preventing flooding is why the dams were put in." He said the state and federal partners have so far signaled limited willingness to fund full restoration and that some nearby counties are moving toward decommissioning their structures. Wojahn described a slim chance that Jersey Valley could be restored as a lake; he said Land and Water indicated it may pay 100% for certain flood-reduction work, but further restoration would still require several million dollars and remain uncertain.

Supervisor Tom Lukkens, speaking during the discussion, criticized proposed DNR chute designs and the agency’s preference for lower-cost fixes, arguing those measures could increase flow velocity and place added pressure on downstream culverts and bridges. Board members and staff also raised the need to update floodplain and hazard maps if dams are removed, and emphasized exploring watershed-level, natural solutions such as deep-rooted native plantings.

The presentation identified trade-offs: continued maintenance of aging dams would leave long-term local liabilities and costs, while decommissioning transfers some hydrologic impacts downstream and requires mapping updates and infrastructure planning. Wojahn said he will return with a prioritized list of dams and funding recommendations for board consideration.