The lock at St. Anthony Falls, no longer used for navigation, could be transformed into a park with an interpretive center and performance space under a plan being floated by a new nonprofit formed by riverfront advocates.

The pitch by the Friends of the Lock and Dam includes a glass-sided observation platform slung over the lock and beside the falls, sloping lawns, concessions and a beefed-up visitor center built atop a 280-car parking garage. It would completely remake the area near Mill Ruins Park, the planned Water Works Park straddling W. River Parkway and the Stone Arch Bridge.

"The bridge is great but on both ends it is still undeveloped … with dirt paths and asphalt parking," said Tom Fisher, director of the Metropolitan Design Center and a board member of the new Friends of the Lock and Dam. "Why not make it a national destination?"

The $45 million proposal, which still needs buy-in from federal, state and local agencies, won't go forward at all, backers say, if the Federal Energy Regulatory Commission (FERC) allows Crown Hydro to generate electricity at the site. The Friends group this week asked FERC to let it argue against a federal license amendment that Crown Hydro needs to proceed.

A Crown Hydro attorney said he couldn't comment until he read the Friends motion.

Crown Hydro has proposed installing intakes and a turbine-generator at the upper end of the lock complex owned by the U.S. Army Corps of Engineers, then tunneling underground past the Stone Arch Bridge to release water downstream.

The plan has drawn opposition from the city Park Board and riverfront residents. The fledgling Friends group, represented by former FERC chairman James Hoecker, argued in its motion that the water power proposal would be inimical to public use of the lock area and could affect historical mill remnants.

The riverfront has changed greatly since Crown Hydro initially sought a federal power license in 1991 — from an industrial milling center to a public attraction that's benefited from investments in parks and riverfront housing.

The Friends motion argues that the hydro proposal is a step toward reindustrializing the river.

Competing proposals

This is Crown Hydro's third attempt to generate power at the falls. If FERC grants its license amendment, it would then need signoffs from multiple other agencies, which could take several years.

The Crown Hydro and the Friends proposals also come as the Corps is seeking funding to study what it should do with the lock — no longer used for navigation and with only a standby flood control role. The adjacent dam is owned by Xcel, which generates hydroelectricity on Hennepin Island.

Big changes already are pending for the west end of the Stone Arch Bridge. Water Works Park, straddling W. River Parkway, will be built in two phases, with backers hoping to start the second phase next to the lock in 2021. The Minneapolis Parks Foundation said it has commitments for $12 million of the $15 million private funding goal for that project and another upriver, but public funding to match that so far is lagging.

Supporters of the new Lock and Dam park proposal say its $45 million cost would also need to be covered by a combination of public and private money. They say they have already secured $5 million in private donations.

The Friends group acknowledges that some of their park plans would duplicate other riverfront features. For example, bathrooms, food and rental space are contained in the Water Works plans. The proposed parking ramp could compete with two city-owned ramps. Mill City Museum already offers space for event rental and outdoor music.

But backers argue that details could be negotiated and their plans would bring the public closer to the locks and falls than the view from the Stone Arch Bridge. The Friends group said a series of public workshops planned for next winter will help flesh out their concept, which was largely developed out of public view.

Visits up this summer

There's already interest in the area.

John Anfinson, superintendent of the Mississippi National River and Recreation Area, said lock visitor numbers have shot up since his agency reopened the Corps' modest lock visitor center this summer, which illustrates the site's potential.

"It puts you on the river," he said. "The mist comes up right there."

The Friends concept is a "bold proposal," he said. "What's important is that we have a conversation about this space."

Steve Brandt • 612-673-4438

Twitter: @brandtmpls