At a ceremonial ribbon-cutting Tuesday afternoon, Duluth city officials celebrated the completion of the first two phases of Lakewalk reconstruction, in the wake of back-to-back storms that damaged the popular path. But Construction Project Supervisor Michael LeBeau acknowledged that the third and final phase of the Lakewalk project along Canal Park will present the greatest challenge.
"You've got 350 miles of lake coming at you clear from Canada," said LeBeau, noting how exposed the vulnerable peninsula is to storm-driven surf.
"I've watched it in some of our recent storms, and it's stunning to see the force of some of those waves," he said.
Yet LeBeau has been tasked with building a Lakewalk that can withstand the pounding surf of Lake Superior.
"I've read that the wave heights and wind speeds in some of our recent big storms were the highest we've ever recorded. But who's to say it couldn't go higher?" he said.
LeBeau noted that the weather is expected to become more erratic as a result of climate change. With Lake Superior's water level already near a record high, and large-precipitation events becoming more frequent, he predicted the forces confronting the Lakewalk are likely to only intensify.
"Whether you're on the East Coast, the West Coast or here, you've got two choices: You build better and higher or you retreat. And I don't think we're going to retreat," LeBeau said.
Yet designing a Lakewalk that's up to the task of facing worsening conditions is a daunting task, LeBeau conceded. "There's definitely some faith involved," he said.
As the Lakewalk is reconstructed in Canal Park, plans call to raise it 3 to 4 feet in places. LeBeau said plans also call for the construction of up to a 10- to 10½-foot tall concrete storm wall.
On Tuesday night, the Duluth City Council passed a resolution authorizing the purchase of more than 76,000 tons of boulders — including at least 72,000 tons of 6- to 9-ton stones and 4,000 tons of 10- to 12-ton stones. LeBeau said the larger boulders, which are each roughly the size of a car, will be used as toe stones at the underwater base of the rock slope installed outside of the storm wall to armor it against waves.
The stone, to be supplied by Rachel Contracting Inc. of St Michael, will be hauled in from near Two Harbors. It will be placed in a temporary staging area along the shore below Endion Station, with the first 25,500 tons scheduled for delivery by May 31.
LeBeau expects the reconstruction of the Canal Park portion of Lakewalk will take most of next season, beginning in the spring and stretching into the fall. Foot traffic in the meantime will be redirected onto a neighboring carriage path.
The cost will be covered with the help of state and federal disaster relief funds. But LeBeau noted the city will need to front the money for the project then seek reimbursements.
In all, the recovery costs from the 2017 and 2018 storms are expected to total between $25 million and $30 million. Those expenses aren't all related to the Lakewalk., however. LeBeau also pointed to erosion behind the city's water treatment plant up the shore that must be addressed and numerous other repairs that must be made to other structures, including stormwater outflows and an observation deck behind Bayfront Park.
LeBeau said some of the work likely will spill into 2021, but he described a strong sense of urgency to get it completed as quickly as possible.
"The water treatment plant is one of our most critical pieces of public infrastructure, providing water for about 160,000 people, and we can't afford to let anything bad happen to it. We need to get these things protected as soon as we can, before we get another really big storm," he said, adding: "It feels like a race."