Posted on November 15, 2021
The pending study required congressional approval.
The U.S. Army Corps of Engineers announced that it has completed a summer’s worth of work to temporarily bolster part of Park Point’s eroding shoreline. But the potentially bigger news is that the Corps has authorized a congressionally approved federal study to examine the cause of the ongoing land loss and to explore possible long-term solutions.
The investigation is expected to take 18-24 months to complete, and is officially called a Continuing Authorities Program (CAP) Section 11 study.
Mayor Emily Larson formally requested the federal study in March.
“We have a chronic long-term erosion problem on Minnesota Point that threatens the public beach, public infrastructure and ultimately private property,” said Jim Filby Williams, Duluth’s director of parks, properties and libraries. “And since the canal was created, placement of dredge materials to rebuild eroded beach has been an essential tool in the tool belt. But that work has not necessarily been carried out in the context of a comprehensive, science-based, long-term plan for all of Minnesota Point, nor has it included other potentially complementary tools that we might utilize to take care of this issue.”
Left to its own devices, the city would be hard-pressed to undertake a study of the magnitude proposed, Filby Williams said, because of the scientific expertise required and the cost, which he said could easily surpass $500,000.
Scientists have long theorized that a breakwall installed at the Duluth Harbor Entry has interrupted the natural flow of sediments that once fed the beaches of Park Point, rendering the slender finger of land ever more vulnerable to erosion.
“The study will investigate whether the federal structures in Duluth-Superior Harbor are causing damages to adjacent shoreline on Lake Superior,” Nick Zager, chief of planning for the U.S. Army Corps of Engineers’ Detroit District, said in a written statement.
“If it is found they are causing damage, the amount will need to be quantified. For example, the study could find 75% is caused by federal structures and 25% by natural erosion. The next steps would be to develop mitigation alternatives and recommend a plan for implementation,” he said.
Filby Williams said the degree to which federal structures are deemed to be responsible for erosion likely will determine what share of the remediation costs federal authorities will bear.
As a temporary measure, the Corps has used sand dredged from the port’s shipping lanes to supplement a portion of beach. It entered into a $1.07 million contract with Roen Salvage to dredge about 53,000 cubic yards of material that were then used to “nourish” part of Park Point’s eroding beachfront, between the pier and the S-curve just north of 12th Street.
Additional precautions were taken this year, as similar beach nourishment efforts the previous year resulted in the inadvertent placement of shredded metal shards on the beach. The displaced litter appears to have been the result of dredging equipment encountering an unexpected trove of metal cans previously dumped in the water.
Besides taking steps to prevent a repeat incident, the Corps also worked this year to locate and clean up the metal debris deposited during the previous year’s project.
A survey of the area found 23 spots with “high-magnetic signatures” — eight on land and 15 under water. The on-land deposits were excavated and screened to remove any metal pieces.
The cleanup entailed mechanically raking the entire beach for debris with machinery several times, as well.
“We are pleased and grateful for the effort and the outcome on both the cleanup from the 2020 beach nourishment project and the successful completion of the 2021 project,” said Filby Williams, noting the extra precautions the Corps took this year to prevent any repeat problems.
A statement from the Corps said: “Beach cleanup efforts indicate most metal fragments have been recovered. However, wind/wave transport of some fragments may lead to fragments washing up on the beach in the future.”
The city of Duluth plans to host a public meeting at duluthmn.gov/live-meeting from 5-6 p.m. Thursday to discuss the 2021 beach nourishment and cleanup efort, as well as the pending CAP Section 11 study.
