The U.S. Army Corps of Engineers is eager to get rid of its lock and dam in downtown Minneapolis, seven years after it closed to barge traffic to prevent the spread of invasive carp.

Problem is, no one seems to want a colossal edifice of waterfall management that will need maintenance in perpetuity.

In addition to its historical significance, the Upper St. Anthony Falls lock and dam system still plays a crucial role in the city's drinking water supply, flood prevention and power generation.

So far, that hasn't made owning the lock appealing to Xcel Energy, which owns the hydroelectric dam; Minneapolis Parks and Recreation, which is developing the Water Works riverfront park; or the city of Minneapolis.

"No one has stepped forward thus far and expressed interest," said Corps' project manager Nanette Bischoff. "The only way that we came up with, to maybe incentivize them to take it, is to offer them a cash payment up front. That's pretty much all that we have our disposal right now."

Congress hasn't specified a dollar amount, so the Corps can't yet say how much it can pay someone to take the lock off its hands.

Any cash offer probably won't entice Minneapolis anyway — not when ownership comes with steep responsibilities.

"The city's point of view is the locks system and the Mississippi River waterway system affects millions of Americans, it affects many, many states, and no one city would have the resources, or the ability, or the knowledge to operate such an important piece of a system," said Jeff Johnson, executive director of the Minneapolis Convention Center.

Only the feds, who created the complex Mississippi River lock system, have the knowledge and resources to ensure it doesn't fail, he said.

St. Anthony Falls catalyzed industrialization of the Twin Cities by powering its earliest lumber and flour mills. But as competing companies seeking hydro power punched shafts through the limestone and sandstone riverbed, the largest of the tunnels collapsed in 1869, nearly causing the falls to disintegrate into rapids.

The nascent U.S. Army Corps of Engineers came to the rescue, plugging the cavities and building a concrete cutoff wall 1,850 feet long by 40 feet high underneath the river to hold up the only waterfall on the Mississippi River.

Afterward, the Corps built a dam for future generations to safely harness water power, and installed a lock for commercial navigation in 1963.

In 2014, Congress ordered the lock closed. The Upper Harbor barge terminal in north Minneapolis became obsolete.

The Water Resources Development Act (WRDA) of 2018 ordered the Corps to study whether there's a federal interest in continuing to own and operate the Upper St. Anthony Falls lock. If not, they had to find a way to dispose of it as a cost-saving measure.

A coalition of conservation groups including the National Parks Conservation Association, Friends of the Mississippi River, and Friends of the Falls objected to the Corps' divestment of the lock, which is still used to manage floodwaters and maintain the water level of the St. Anthony Falls reservoir. Minneapolis, St. Paul, and 16 suburbs rely on it for their water supply.

The Corps initiated its study, but before it could finish, Congress passed WRDA 2020 amid local opposition to the feds leaving the lock. It clarified, "the Secretary [of the Army] shall retain all rights to operate and maintain the Upper St. Anthony Falls Lock and Dam." At the same time, it directed the Corps to give adjacent land — including a parking lot, some grassy areas, and an observation building — to the city of Minneapolis for recreation.

Friends of the Falls and the Native American Community Development Institute (NACDI) want to redevelop those properties in a way that recognizes the area's original Dakota residents, who were exiled from Minneapolis.

Community engagement is still underway, but NACDI president Robert Lilligren said initial feedback includes commemorating the destruction of sacred sites along the river. These include Spirit Island, which was quarried for limestone used to build Minneapolis.

The waterfall "was destroyed through greed, essentially, and industrialization," Lilligren said. "So one of the things we heard from the community when we were doing the Water Works community engagement was [wanting] a place where Native people felt was theirs and they were welcome."

As for the lock, the Army Corps still wants to find a new owner, despite the 2020 law's instruction that they operate and maintain it.

During a public meeting last week, Corps project planner Sierra Keenan said this is because WRDA 2020 doesn't explicitly rescind WRDA 2018, which directed the Corps to study disposition. "I understand it's confusing and the Corps' viewpoint is not shared by all our stakeholders," she said.

The Army Corps has calculated it would cost $7 million over the next 50 years to hold on to the lock.

Members of the public who attended the meeting had many questions, but none expressed support for the Corps' plan.

John Anfinson, a Friends of the Mississippi River board member who was the Corps' district historian for many years, recently presented another consideration not addressed in the Corps' disposition study.

The cutoff wall that the Corps built beneath the falls 144 years ago is a hidden dam that keeps the St. Anthony falls reservoir in place, he said.

"Nearly one million Twin Citians depend on the Mississippi River for their household water," Anfinson wrote in an essay that has circulated to key stakeholders.

It's unclear who owns the cutoff wall now, but Anfinson believes the Corps should be responsible for repairing it if it breaks.

"The Corps builds many pieces of infrastructure under emergency orders, but does not end up owning the structure afterward," said Bischoff, who doesn't know who owns the wall.

"The Army Corps of Engineers built the cutoff wall ... nearly 150 years ago, well before Xcel Energy was using the river to generate electricity for our customers at the Hennepin Island Hydro Plant," Xcel Energy said in a statement. "It is not included as a physical structure of our hydro plant under our Federal Energy Regulatory Commission (FERC) license."

The Corps will receive public comments and plans to forward its final lock disposition report to Congress for consideration in September.

Susan Du • 612-673-4028