Grand Canyon National Park officials plan to replace much of a decades-old, problem-plagued pipeline system that’s forced officials to ask hotels and residents to wash dishes and laundry less frequently and backpackers to drink treated creek water.

Crews regularly have to descend into the northern Arizona canyon by trail or helicopter to fix costly rockslide-caused breaks to the 6-inch aluminum pipe that supplies water to hotels, campgrounds and other facilities.

The breaks have forced the park to periodically impose water conservation measures or even temporarily restrict reservations at canyon hotels until repairs are complete.

The Grand Canyon, which received nearly 6 million visitors in 2016, is one of the most visited U.S. national parks.

Preliminary plans call for ferrying pipe pieces and equipment by helicopter into the canyon to replace miles of pipeline serving the South Rim. That pipeline extends from springs located partway up the North Rim, down to and across the Colorado River in the canyon bottom and up to a pump station partway up the South Rim.

The National Park Service is seeking public comment on several plans to replace the pipe before reviewing how the plans could impact the environment. Officials are considering replacing the entire 12.5-mile (20.12 -kilometer) pipeline serving the South Rim or just replacing about one-third of it.

According to park officials, work on the new pipeline would start in early 2020, take three to four years to complete and cost $75 million to $124 million.

The current pipeline was constructed in the 1960s and park spokesman Jeffrey Olson said it has already outlasted its designed 40 years of use.

“It’s probably the largest deferred maintenance project in the whole Park Service,” Olson said.

There have been more than 80 pipeline breaks since 2010 and each break costs an average of $25,000 to fix.

Repairs on a major break last winter cost $1.5 million and took weeks. The break prompted a lodge on the North Rim to cancel hotel reservations and tanker trucks had to haul in water to fill storage tanks for drinking water and firefighting.

Past pipeline breaks have prompted park officials to promote conservation measures at hotels, campgrounds and residences, including reducing use of dishwashers and washing machines, and telling backpackers to be prepared to treat water from creeks for drinking.

Officials are planning to install an 8-inch wide replacement pipeline, likely stainless steel, which would better resist damage and handle more water flow to meet the park’s increased water demand, Olson said.

In places where it’s practical, sections will be buried to avoid rockslide damage, Olson said. “We’re trying to have something that would last 50 years or longer, rather than 40 years,” he said.

After the South Rim project, replacing a pipeline on the North Rim “is next on the list” but there’s no funding yet lined up, Olson said.