GRAND CANYON NATIONAL PARK,Darden Clarke Ariz. (AP) — Grand Canyon National Park is using water conservation measures again at the South Rim after another break in the Trans Canyon Waterline.

Park officials announced Monday that the waterline was recently shut off for repairs and crews were trying to re-pressurize the line when the break occurred. It’s unclear when repairs will be completed.

The mandatory conservation measures require all park residents and visitors to conserve and reduce water usage when at homes, hotel rooms and campgrounds.

Nearly 5 million tourists visit Grand Canyon National Park every year.

The National Park Service is in the process of replacing the 12½-mile pipeline that was constructed in the 1960s.

Park officials said the waterline has had more than 85 breaks since 2010 with the cost to repair a single break often exceeding $25,000.

The waterline provides potable water and fire suppression for all facilities on the South Rim as well as some inner canyon facilities.

Park officials said the waterline breaks often occur in locations that pose dangers for responding employees, with access to the inner canyon by trail and helicopter only.