Drivers in the west metro soon will need to figure out some alternate commuting routes as a $5 million construction project will close part of Hwy. 7 in Minnetrista beginning about mid-July and continuing through late fall.

Minnetrista is building a roundabout and pedestrian underpass at the highway’s junction with Kings Point Road. It is the first of several changes that are part of the Woodland Cove development further north on Kings Point near Halstead Bay in Lake Minnetonka.

That massive residential project is slated to add more than 1,000 housing units over the next decade on 490 acres of farm fields, forests, wetlands and rolling hills.

The intersection of Kings Point Road and Hwy. 7 is one of the two main entrances to the development, said Minnetrista City Administrator Mike Funk.

“We needed to improve access onto Hwy. 7 and do it in a way that’s the most safe and effective method possible,” he said.

The roundabout is a complicated project that includes realigning roads on the north and south sides of the roundabout. The developer will reimburse Minnetrista for all costs of the project, Funk said, except for about $600,000 that the Minnesota Department of Transportation is providing.

A detour will route truck and other traffic from Hwy. 7 south to Hwy. 5, although Funk expects many commuters to figure out shorter routes on local roads. Almost all of Hwy. 7 will be open to local traffic, he said, except for the half-mile segment near the Kings Point Road intersection.

The community most affected by the detour will likely be St. Bonifacius, a community of about 2,300 just west of the roundabout. State highway counts in 2010 estimated that 14,600 vehicles drive through the city on an average day.

“Hwy. 7 goes right through the heart of our downtown district,” said St. Bonifacius Mayor Rick Weible. “We’re very concerned that this is going to hurt business because people will think St. Boni is closed.”

The city will sponsor special events to draw people downtown, Weible said, and is working with MnDOT to display signs near the detours that the city is open for business.

For Minnetrista, the roundabout is the kickoff for much more work ahead.

Kings Point Road itself will be reconstructed in the fall, and its 1.6 miles will be rebuilt with new sanitary sewer lines and water mains that will serve the Woodland Cove development and other growth.

Public meeting is next week

City engineer Mark Erlichson said the road reconstruction will cost about $3.4 million. “We’re working quickly to pull all the plans together,” he said. Those who live along the road have been invited to a public information meeting next week.

The Kings Point Road project could begin as soon as September, he said, with a goal of ­completing it by the end of the year.

It will probably coincide with the first home construction, Funk said, and the city expects a final plat application soon for the first phase of the development.

Woodland Cove has sold some of its land to a builder, he said, and home construction could be underway as early as this fall. Phase one is likely to include mixed-use residential development, Funk said, with 220 units of single-family homes, duplexes and row houses.

The first phase will not include the large lakeside lots with custom-built homes, he said, or any commercial building.

“As a city, this is an exciting time for us,” Funk said. “We’re a growing city, and we’re expected to grow. And we’re embracing that growth.”