Surviving a flood: Redridge dams suffered damage but kept water back during Father’s Day flood
By the beginning of the new millennium, the Redridge dams were owned by Stanton Township and roughly as you see them today, with a couple exceptions. Under recommendation from the then-Department of Environmental Quality, the upper, timber portion of the older, rock-fill dam was removed in 2004, lowering it by about 13 more feet.
“The Redridge Dam is in fair condition,” the inspection reports from 2005 and 2014 say. “There were no deficiencies observed during the inspection that would lead to failure of the dam.”
The inspector went on to recommend the removal of trees and shrubs on the dam embankments, the continued planning for the repair or removal of the timber crib dam, and the development of written plans for operation, maintenance, and emergency action.
That might still be the condition of the dams today, if it were not for the heavy rains of Father’s Day 2018.
“The best we can tell, the water went up about two-thirds of the dam,” Stan Vitton said.
Vitton is a professor of civil and environmental engineering at Michigan Technological University. He grew up on the Keweenaw Peninsula and is now part of a group of locals working to preserve the Redridge steel dam as a national landmark.
During the Father’s Day event, water rushed over the timber crib dam, and culverts under the road to Freda were temporarily plugged, causing the water to rise along the road’s embankment. Vitton believes the steel dam is the only thing that kept the road from being washed away.
“The steel dam became something of a baffle,” he said.
Even though the dam had six 4-by-8 holes that let water pour through, it was still holding back a significant amount of the flow, too. Enough to, Vitton thinks, keep water from overtopping the road and washing it away.
The steel dam, however, did not escape unscathed. Not only did a significant amount of the concrete base behind the dam get eroded away by the torrent of water and debris, but one of the major steel supports was broken completely loose of its concrete mount. Left to deteriorate, these structural deficiencies will lead to the eventual failure of the dam.
If the dam did fail, Chris Van Arsdale has not just a plan, but the plan. The Emergency Action Plan, to be specific.
Van Arsdale is the Emergency Management Coordinator for Houghton and Keweenaw Counties. His full-time job is to keep the EAP updated with emergency contacts, available resources, and important considerations for every kind of emergency imaginable for Houghton and Keweenaw counties.
“It’s not so much like ‘do this’ it’s more like ‘should you do this’, or ‘have you considered this?'” Van Arsdale said. “In the moment, these might not be obvious things to think about.”
He said the open-endedness in the plan is to keep the plan, and the people using it, flexible and responsive to unanticipated situations.
While some dam failures would require an immediate public notice component to the plan, in Redridge’s case, Van Arsdale doesn’t think it would help much. The proximity of the dam to Lake Superior means the few people in the floodplain would be aware of the problem well before any message could be arranged and sent. But there are other considerations.
“The big one would be access for fire and EMS… to the homes south of there,” Van Arsdale said.
Depending on the details of the situation, options include logging and ATV trails, a temporary replacement culvert, ferry boat service, or an emergency temporary bridge called Acrow Bridge.
The EAP is not available to the public, both because of the personal contact information included, and because the detailed information about public infrastructure and emergency response information is something sought after by terrorists.
However, the 2018 damage to Redridge is not being just left to further decay.
This article is part of a series on local dam conditions.
Part 1: Click here