It's out with the old at popular French Regional Park in Plymouth

French Regional Park in Plymouth, one of the metro area's most visited parks, is about to get a major makeover.

Three Rivers Park District officials launched the $4.4 million project last week by hiring a design engineering firm. The work — which will include new paved trails, roads, parking areas, and a boat ramp and water system — will be done in phases beginning this fall so the park can stay open.

French Regional, on the north shore of Medicine Lake in Plymouth, is the third-most popular park in the Three Rivers system, after Hyland Lake Park Reserve in Bloomington and top-visited Elm Creek Park Reserve in Maple Grove. The number of visits to French has steadily risen, with nearly 570,000 visits in 2012 — up about 55 percent over the past five years, according to Metropolitan Council estimates.

Nearly all paved surfaces in the park need "wholesale replacement," said Eric Nelson, Three Rivers' senior manager of engineering. The work will include 3 miles of trails, 1.8 miles of road and about 6.7 acres of parking lots, he said. Most of the roads and parking lots were last paved in 1988, he said, and the trails in 1991, so everything is well past the point of patching.

The work will not add parking spaces or trails, Nelson said, but simply replace what is there and improve stormwater runoff.

"It's going to be phased so one parking lot is closed at a time, or maybe one lane in each direction," he said.

The pavement work will be done during the late spring and summer of 2015, with specific details of the timetable still to be worked out.

The Park District completed similar pavement overhauls in Fish Lake Regional Park in Maple Grove in 2013 and Baker Park Reserve in Medina in 2012.

The first work at French will be replacement of the park's entire water system and boat ramp later this year.

The water system has had 10 breaks since 1998, Nelson said. Some of the cast iron pipes date to the 1970s, when homes on the land were acquired for the park, he said. The Park District installed other iron pipes in the 1980s that have corroded.

The revamping of the water system will feature plastic pipes that last longer, Nelson said. It will also include improvements to sections of the sanitary sewer system and better management of stormwater.

The most visible change in 2014 will be replacing the boat launch, he said. It is used for about 7,700 launches each year, and has large gaps between its deteriorating concrete planks. Heaving of planks because of ice has also been a regular maintenance problem, he said, and the ramp backs into water that's too shallow for larger boats.

"We're in communication with the city of Plymouth to make sure that their ramp on the west side of Medicine Lake is ready and available to be used as an alternative boat launch in the fall," Nelson said. "As we get to the end of the year when people who live on the lake are looking to get their boats off [for the winter], we definitely want them to have options."

Besides the summer draw of swimming, boating, canoeing, fishing and sailing, French Regional Park also has two large picnic shelters and several lakeside picnic sites. The Medicine Lake Regional Trail crosses through the park and links it with two other trails and two other regional parks.

The park was named after Clifton E. French, former superintendent of what used to be called the Hennepin County Park Reserve District.

During French's tenure from 1960 to 1984, the suburban park system grew from 1,400 to 24,000 acres with a goal of keeping 80 percent of the land in its natural state, and the other 20 percent developed for recreation compatible with the natural environment.

Tom Meersman • 612-673-7388