Following the November 7 announcements by the Maine Department of Transportation (DOT) that it was immediately closing part of the Machias dike in preparation of replacing the failing structure and that it was pivoting from a bridge as its preferred replacement option to a dike with fully gated culverts, questions have arisen for Machias residents. The timeframe involved for the replacement, access to vendor space and how well the replacement structure will mitigate flooding are among the leading concerns.
      As far as timing, residents and those passing through Route 1 will see major changes in the area soon. Parts of the shoulder and parking area of the dike are currently closed due to concerns over "increasing voids" beneath the dike, according to the November 7 DOT press release. The next step will be to close the dike entirely for a week to install a temporary modular steel structure called a Mabey bridge, says Paul Merrill, director of communications at the DOT. "We're hoping to install the temporary bridge between Thanksgiving and Christmas," Merrill says.
      During the installation of the temporary bridge, traffic will be rerouted for a week. Northbound traffic will be routed through Route 192, Ridge Road and Hadley Pond Road, adding 3.7 miles, Merrill says. Southbound traffic will use Rim Road to Route 92, adding 2.3 miles.
      Whether the temporary structure will allow for vendors tops the list of questions for some residents. Through the winter, approximately a dozen vendors use the dike to sell their wares, according to Town Manager Bill Kitchen. In the summer, it's not uncommon to see 30 or more vendors using the space. "We are hopeful the impact area is what is currently coned off," Kitchen says.
      The DOT has not yet determined how much of the space will be usable by vendors, but Merrill says there will be some. "Vendors will still be able to show their goods in the area. I'm not sure of the exact location, but they will not be completely prohibited."
      Similarly, the Sunrise Trail will be fully accessible while the temporary bridge is in place.
      The design phase of the dike will take place in 2024, with construction potentially started in 2025, although that could be delayed if legal challenges to the design are raised. With the DOT switching from one "nuclear option" to another, according to Machias resident and University of Maine at Machias (UMM) geographer Tora Johnson, the possibility of challenges based on how well the dike will serve the area is a real one.
      "It's not actually an in kind replacement," Johnson says of the proposed plan to build a dike with fully gated culverts. "We don't currently have closed culverts. The gates that are in there have been damaged for years."
      Currently the existing dike -- completed in 1868 -- allows for some absorption of floodwaters when the area experiences a storm and subsequent sea surge. This is largely due to the open spaces underneath it, which allow rising sea waters to pass through and up the Middle River.
      If the DOT continues with its proposed fully gated culvert system, it will effectively be building a seawall, Johnson says. The energy from the storm and ensuing flood would be reflected on the other end of the bay, causing erosion and damaging downtown infrastructure.
      Flooding and storm surge are a "very significant concern" for Machias, Johnson says, and storm surges are rising each year along with the sea level. She references April 2020, when significant flooding almost caused the dike to be swept away entirely. That storm was 11.2 feet above sea level, several inches higher than the 10.8-foot marker achieved by the flooding in February 1978 -- which was the previous benchmark the Federal Emergency Management Agency used to determine a 100 year storm. Both of the storms were similar, Johnson says, with the difference in height achieved by sea level rise over the past half century.
      Rising sea levels and more frequent storms are a real danger to coastal Maine, including Machias. "We've had five 100-year floods in six years," Johnson says. "That's the level of vulnerability we're at" for the downtown area.
      Instead of installing the dike with closed culverts as it is currently proposing, the DOT could limit flooding, Johnson says, by starting with some open culverts and some gated culverts. That would be a proper in kind replacement for the current structure, considering its gaps. Additionally, Johnson proposes that the other culverts could be gradually opened over the span of years to improve flood absorption and increase fish flow, although she notes that improving fish flow is a secondary concern compared to mitigating flooding.
      While the previously proposed bridge would have reduced flooding concerns for the downtown, it would have put approximately 54 upriver properties, 400 acres of land and the old landfill at risk for more flooding. The alternative "seawall," however, puts the downtown at increased risk, Johnson says. Finding a middle road is therefore critical.
      Merrill says the DOT considered different combinations of open and closed culverts before deciding on its current choice of closed culverts, but he adds, "MaineDOT is continuing assessment of potential impacts of the preferred alternative, consulting with federal agencies and collecting public input." He also clarifies that the selection of the dike over the bridge was not prompted by the suddenness of the current dike's deterioration but was made after 16 months of collected input.
      Another flaw that Johnson sees is that the dike is not being elevated from its current footprint "as if the flooding hasn't happened yet," she says. "I saw waves washing over the dike in 2020. It had to be plowed afterward because of the seaweed on it." According to Merrill, the DOT will be designing the dike in alignment with state standards that expect 1.5 feet of sea level rise by 2050 and 3.9 feet by 2100.
      For Johnson, the potential flood damage in Machias is not an issue that she will be letting go of. In January, she'll be starting a new position with Sunrise County Economic Council as the co director of the Sustainable Prosperity Initiative for the area. "This is definitely going to be front and center of that work."