The city of Boulder and the National Institute of Standards and Technology have shut down a few well-worn social paths east of NIST's campus because of erosion risks.

Just south of Green Mountain Cemetery on NIST land a concrete bike path along Skunk Canyon runs parallel about 40 or 50 yards below a dirt service road that leads up to Kohler Mesa. There are several social paths that cut between the road and the bike path, and the city and NIST have erected signs at three of the more well-worn paths in the hopes of eliminating those paths.

"What we're trying to do is reduce and eliminate the erosion issue," said NIST spokesman Jim Burrus. "The erosion in some places is very significant."

Burrus said during recent rains, some of the paths turned into ravines 20 inches wide and up to 30 inches deep in places, and said continued erosion could cause problems for NIST, the city of Boulder and neighboring residents.

"If that is allowed to continue, it creates an issue for everybody," Burrus said. "We're trying to restore that so it doesn't become a bigger issue."

The land is owned by NIST but is part of 103 acres surrounding the campus managed by the city of Boulder in exchange for NIST allowing public access on designated trails in the area.

Jim Reeder, an open space division manager with the city of Boulder, said depending on the weather conditions and whether people respect the closures, the paths could take about a year or more to be completely restored.

"It is always kind of wait and see," Reeder said. "Typically in the environment we have out there with fairly fertile ground, I wouldn't be a bit surprised — if we can keep people off of it — that maybe next fall it will be restored to the point that we can take the barriers down."

In the meantime, Reeder pointed out in addition to point at the beginning of the path where it connects with the service road, the city has put in another access point about halfway through the bike path for people to get to the service road without creating their own paths or following social trails.

"There are other ways for the neighbors to access that service road," Reeder said.

Burrus said he hopes people using the path will understand why the closures were necessary and keep off of them to speed up the restoration process.

"I think people understand, at least here, that human nature is to find the shortest distance between two points," Burrus said. "We are not trying to close off every impromptu path, but where we are having problems, we are hoping people will see that and respect the closures so we can get that rehabilitated."

Contact Camera Staff Writer Mitch Byars at 303-473-1329 or byarsm@dailycamera.com