Minneapolis considers bridging Lake Calhoun, Lake of the Isles

Summertime's busiest spot in Minneapolis has park officials considering putting a lid on it.

A Lake Street lid, that is.

That's the name some are attaching to a bold proposal to install a costly land bridge over the six-lane street at the Lake Calhoun-Lake of the Isles nexus where every day thousands of people head to play.

The concept is to depress Lake Street slightly, then bridge it with a grassy crossing for bikers and pedestrians that would tie together adjacent Isles and Calhoun parkland, while relieving pinch points for recreational congestion at Calhoun's northern corners.

"Trail safety concerns have become a real issue," said Bruce Chamberlain, an assistant park superintendent.

The Lake Street Lid emerged at a Park Board design charrette last fall aimed at defining improvements in the north Calhoun-south Isles area for a request for future regional park funding. Its focus was to look at ways to alleviate congestion among walkers, joggers, bikers, patrons of Tin Fish restaurant, and sailors and other boaters, especially in the Calhoun refectory area.

"When the consultants presented that idea, it took our breath away," said Mike Wilson, a neighborhood representative to the charrette. "We looked at it and said, 'My gosh, that's really an excellent solution.' It's very doable — as with many things it's a matter of money."

How much? One park official's very preliminary estimate ranges between $15 million and $40 million, depending on length. Three options for how long a segment of Lake might be covered range from 150 feet (half the length of a football field) to 1,200 feet (four football fields long). The most likely location would be where Lake Street runs closest to the Midtown Greenway, a bike-pedestrian path, on the lake's north end.

Study alone deemed costly

A handful of land bridges have been proposed in the Twin Cities previously but have fallen by the wayside due to cost. Minnehaha Park has one, where a park-highway conflict produced the construction a dozen years ago of a 600-foot-wide wide bridge that carries Minnehaha Parkway over Hwy. 55, and includes parking, paths and a floral garden. But the history of land bridge proposals in Minneapolis is more littered with suggestions than completions.

Chamberlain wants to look at how practical the Calhoun-Isles bridge would be with a $200,000 to $250,000 feasibility study. The water table in the area likely limits how much Lake could be depressed.

The greenway would be put on stilts over the land bridge to make the ground-level connection continuous from Isles shore to Calhoun shore.

Park commissioners reacted cautiously. Board President John Erwin said the feasibility study's cost alone was "quite a bit of money." Moreover, with several significant projects already on the drawing boards, commissioners are reluctant to add another to compete for park development money. There's $21 million in work proposed for Wirth Park, plus $17 million more for redeveloping the Scherer Lumber site on the northeast riverfront. Commissioner Jon Olson made clear he wants a feasibility study and a state bonding request readied for the North Side 94 land bridge proposal, which arose from riverfront planning, before he's ready to support the competing proposal.

Crowding has intensified at Calhoun's northeast corner in the summer months. The Midtown Greenway, for example, draws more than 3,000 bikers on a nice summer weekend day, adding to traditional bike path traffic. Both the greenway and Tin Fish restaurant at the refectory have opened since the last redesign of Calhoun 15 years ago. A yacht club has 60 members, a sailing school serves 1,500 youths, and there are boat rentals.

There's consensus that while a land bridge to reroute some of the intersecting demand is a long-term wish, relief is needed sooner. One idea is to move boating facilities to the lake's northwest shore, where the parkway could be realigned to create more lakeside space. Another idea is to cantilever a bike-only bridge on the Calhoun side of the bridge that carries Lake over the lagoon between Calhoun and Isles. Still another is to build a path under that bridge on the lagoon's west side to match one on the east side, so that bike and foot traffic could be separated. But not all of those would fit within the planned bonding request, and altering the lagoon bridge could draw historic preservation objections.

Outside funding helps the cause

Still, the sheer volume of users will be a boost to efforts to fund both short-term and longer-term improvements. The Park Board estimates that the Chain of Lakes Regional Park, which includes Calhoun and Isles, draws 5 million visitors annually, more than any other park in the state.

Lake Street north of Calhoun draws 39,300 vehicles on an average day, making that the second busiest section of Hennepin County road and the busiest county road in Minneapolis.

The county could be a key partner in a land bridge because it controls Lake Street. "While they're an engineering challenge, they're not impossible to design, but they are very expensive," said Jim Grube, the county's transportation director.

They've also been easiest to do where outside funding is available. In Duluth, for example, highway money put Interstate 35 underground for about four-tenths of a mile in two sections. At Target Field, the publicly funded plaza with Kirby Puckett's statue sits on a land bridge over Interstate 394.

That means that the Park Board will need to seek financial help, as well, facing mounting maintenance and development priorities. "We have to be very clear about what doesn't get done," Commissioner Scott Vreeland said.

Steve Brandt • 612-673-4438

Twitter: @brandtstrib