A major shipper in the Twin Cities area has approached the University of Minnesota about using its riverside dock in Minneapolis for loading of sand and gravel, setting off alarms among river and neighborhood advocates.

Eagan-based Aggregate Industries' proposal highlights how seriously the company is taking the loss of its ability to ship through St. Anthony Falls next June.

That's when a key lock closes at the Upper St. Anthony Lock and Dam, cutting off access by river to the yard Aggregate Industries runs upriver at 26th Avenue N.

The Mississippi Riverfront Partnership is sponsoring a forum Thursday at 6 p.m. at Mill City Museum on how the closing will affect both the river and Minneapolis. It has drawn some 130 advance registrants.

Kathleen Boe, the partnership's executive director, called the proposal "a real disappointment to a lot of people. It's at odds to how we see the future of the riverfront."

The company did not respond to a Star Tribune inquiry Wednesday.

The university has an East Bank barge dock just downriver from the 10th Avenue Bridge that has been used by the U.S. Army Corps of Engineers for dredging nearby. Those familiar with the proposal indicate that it would allow sand and gravel shipped upriver by the firm to be trucked in the Minneapolis area or to the firm's upriver yard.

The U said in a statement that it was approached by the company. It called the proposal complex and said it would require approval by several local and federal agencies.

"The University shares the concern that this may not be an appropriate solution on U of M land on the riverbank," the statement said.

But in an e-mail to one advocate, Jan Morlock, a university community relations official, said the school had declined the request. Citing area plans for new trails, Morlock said, "There are a lot of other reasons why this wouldn't make sense for the University."

The attempt by Aggregate Industries comes as the city's central and upper riverfront plans are changing how the river is used.

The firm got its first taste of that effort in the 1980s, when the Park Board paid to move it 2 miles upriver from the foot of Portland Avenue near the falls to make way for what become Mill Ruins Park. The city's upper river plan now calls for heavy industry to move off the river, but Aggregate Industries has said it plans to stay put.

Marcy Holmes area resident Ted Tucker, who chaired a recently completed falls area park plan, said any new shipping facility would make it hard for those plans to move ahead. A shipping facility would conflict with a proposed bike/foot trail along the top of the bluff between the Stone Arch Bridge area and East River Road, and a roughly parallel footpath lower on the bluff. Neighbors say they are concerned about possible increased truck traffic.

A draft resolution opposing the proposal came before the Marcy Holmes neighborhood group Tuesday night for consideration in February.

The corps already has decided with the lock closing to limit locking hours next year at the Lower St. Anthony and Ford dams.

Mary Maguire, a Marshall Terrace area resident, who sits on the advisory committee for upper river planning, said she expects it to oppose the firm's proposal.

"As a business, I understand where they're coming from," she said. "It just seems totally inappropriate to put industry there at this time."

Steve Brandt • 612-673-4438

Twitter: @brandtstrib