A popular riverfront route for commuting and recreation in Minneapolis could remain impassable until August of next year, following a mudslide in June.

A portion of West River Parkway was closed near the University of Minnesota when heavy rains caused a hillside to collapse near the University of Minnesota Medical Center on June 19. That blocked the area’s use for more than 6,900 vehicles and 1,000 bikers a day, who may have to put up with the obstruction for the bulk of two summers.

The road and its adjoining paths are a calm connection between the southeast quadrant of Minneapolis and downtown, offering picturesque views of the river along the bending and occasionally hilly route.

Reconstruction is expected to begin next spring, said Park Board officials preparing to hire an engineering firm to survey the site. The terms of that contract with Barr Engineering envisions construction ending in August 2015.

“If things go well and we have a good construction season, then it’s likely that we’d be able to finish that work significantly sooner,” said Bruce Chamberlain, assistant parks superintendent. “But we should all be prepared for that possibility of going into August.”

The total cost of handling the collapse, including construction, is estimated to be about $6 million, he said. The Park Board probably would pay about three-quarters of the cost, with the hospital covering the rest. Disaster aid from the Federal Emergency Management Agency is expected to reimburse 75 percent of the cost, and the Park Board hopes that the Legislature will cover the balance.

Precisely what the reconstruction will look like remains unclear. Chamberlain said officials have discussed adding retaining walls or deploying special nails deep into the soil to hold the slope in place.

The recommendation to hire an engineering consultant to oversee a permanent repair notes that Barr Engineering is urging that no construction occur in the winter months, when fluctuating temperatures will send groundwater in the hillside through a freeze-thaw cycle. “We can’t do winter construction,” Chamberlain said. “So we wouldn’t want to start this project and then leave it halfway finished through the winter.”

That, coupled with the need to secure a federal disaster declaration and the prospect of a three-month bidding process for the construction contract, contributed to the project’s long timeline.

The proposed contract for up to $640,000 with Barr goes before the Park Board for a vote Wednesday. That covers further investigating the conditions at the collapse site, designing a repair and overseeing construction.

Temporary measures have been installed to prevent further collapse. They include an impervious fabric to shield the hillside from rain and the diversion of stormwater that flows from the hospital area away from the hill.

Council Member Cam Gordon, who represents the area, said constituents who have contacted him are frustrated.

“Expectations were that it might be open sooner,” he said. “So I try to generally tell them that we’re going to have to wait a lot longer than you might have expected.”