Boulder's Open Space and Mountain Parks Department announced Thursday that, despite the fact that it expects to reopen 80 percent of the city's trail system by year's end, several areas will remain closed into 2014 so that significant repairs can be made.

Open Space and Mountain Parks identified the following areas as those that will be closed into next year:

The Fourmile Creek Trailhead. Officials say that floodwaters forced the creek to expand to 10 times its normal width, creating the need for a new bridge and the clearing of extensive debris before the area can open again.

Chapman Drive/Tenderfoot. The road was severely damaged, and the city must create a walkable trail in the area.

The access road to Green Mountain Lodge. The flood created a flowing creek in the roadway, preventing access to the Ranger Trail and Gregory Canyon. Reopening it too soon would "damage environmental resources," according to a city news release.

East Boulder Trail at Boulder Creek (White Rocks). Large gullies and debris have severely damaged the trail, according to the city.

A photo gallery documenting the state of the city trails that will remain closed until next year is available at http://bit.ly/16RxFAt.

Open Space and Mountain Parks officials noted that 77 miles of Boulder trails suffered significant to severe flood damage, and dozens of additional miles suffered lesser damage.

Since the flood, the department has worked with volunteers to reopen 70 miles of trails and 20 trailheads, as well as climbing areas on the First and Third Flatirons, according to the news release.

Following volunteer projects this weekend, 50 percent of the city's trail system is expected to be reopened, with many more trails expected to reopen in the coming months.

For an up-to-date list of reopened trails, visit http://bit.ly/15msF85.