Environmental assessment for Transcanyon Pipeline due this fall
GRAND CANYON, Ariz. — Grand Canyon National Park has nearly six million visitors per year, from viewpoint drivers to hardcore hikers and even man’s best friends, and they all need to stay hydrated. And, according to a recent news release from the park, hydration is even more critical as summer heat settles in.
While many visitors may grab a water bottle at a convenience store or pack a cooler before leaving their hotel rooms, those on extended hikes into the inner canyon or making the trip to Phantom Ranch rely on water available at drinking stations along the trail.
Kris Provenzano, Grand Canyon program manager at the National Park Service’s regional office in Denver, said the Transcanyon Water Pipeline breaks about once a month, on average. If the break is severe enough, water levels at the South Rim can be drastically affected, resulting in strict water conservation measures and sometimes even requiring the park to haul water in just to meet basic needs.
Originally built in 1965, the aluminum pipeline that feeds the South Rim from roaring Springs has far exceeded its estimated 40-year lifespan. In July 2017, the park entered the public scoping and environmental assessment process to find a solution to replacing the critical pipeline. Two options were offered, along with a third option of not replacing the pipeline at all.
The first option would replace the pipeline along its existing route from the current intake system at Roaring Springs to the Indian Garden Pump Station. From there, the existing Pipeline would continue to deliver water to the South Rim storage tanks. The second plan calls for installation of a new water intake system near Bright Angel Creek at Phantom Ranch, replacing the pipeline from Phantom Ranch to Indian Garden Pump Station and building water treatment facilities at Phantom Ranch, Indian Garden and the South Rim Village.
To test the viability of the second option, the park planned to drill a series of test wells near Phantom Ranch. Provenzano said the drilling did not go as planned.
“We were assured that the drill rig would be able to install the wells through the soils at Phantom Ranch easily, but that was not the case,” she said. “We were only able to install one well, (so) we will be going back to the site this fall with a different type of drill rig to complete the well installation and testing work.”
Provenzano said the well tests are necessary to design the shallow gallery well to support the intake from Bright Angel Creek.
While the test wells did not go as planned, Provenzano added that NPS is conducting other tests and preliminary designs that could support either option, such as geotechnical survey work to document the rock and soil types the replacement waterline will encounter.
“While the waterline is being replaced in the same corridor, we propose burying it deeper and so need to understand what types of soil and rock we will encounter to better estimate schedule and cost,” she said.
According to Provenzano, replacement of the pipeline, through either option, is going to take about 3.5 years to complete. Since the only transportation into the canyon is by foot, mule or helicopter, Provenzano said the park is estimating about 3,000 helicopter flights into an area where visitors expect to encounter silence or enjoy the natural ambiance. Additionally, construction crews will need to be housed in a community with already-tight housing options. Sections of some of the park’s most popular trails, including the heavily-used Bright Angel Trail, could be closed for up to a year.
Provenzano said the environmental assessment will determine which option the park ultimately chooses, and it should be released for public comment as scheduled this fall. Once an option is chosen, Provenzano said construction is anticipated to begin in late 2019.