Flash flooding causes major damage to the Grand Canyon's critical water pipeline

WASHINGTON (AP) — The sole pipeline that supplies water for millions of Grand Canyon visitors was badly damaged by weekend flash flooding, setting up a tricky repair scenario and upending a yearslong construction project to upgrade the line laid over… The long-term implications of the damage to the park's infrastructure, visitors and year-round residents weren't immediately clear. The 12.5-mile (20-kilometer) long Transcanyon Waterline has endured dozens of breaks in recent years.

A more than $200 million repair and replacement project was well underway when the floods hit.Caused by heavy rain, the floods killed at least two people, left more than a dozen others missing or unaccounted for and required the evacuation of more than 60 people. Officials said significant water reductions are needed — short showers, turning off the tap while brushing teeth and flushing toilets selectively to to protect the limited stored water on the South Rim, where most visitors go.Even routine repairs can be trickyThe pipeline, which was finished in the 1970s, has broken more than 85 times since 2010. It moves water from one side of the canyon, down to its base, across a bridge and back up the other side of the rough landscape.

Any effort to fix a break from rock falls or flash floods is time-consuming, precarious and costly, so addressing the latest damage will be complicated.The pipeline upgrade project, which began in 2023, took more than a decade to design, consider and fund. It involves moving the point where water would flow into the pipeline, installing helicopter pads, building water treatment facilities and replacing several miles of pipeline.Basic decisions were complicated. For example, the original pipe was aluminum, which is lighter and easier to move into the steep canyon but is susceptible to breaking.

Engineers picked a flex-steel material to balance weight with durability.Frequent breaks cause water restrictionsEven routine pipeline breaks force water restrictions. In 2016, a hotel on the canyon's rim that offers luxury dining and boasts about its history hosting presidents was forced to reduce dishwashing and use paper plates and plastic utensils.The park had water conservation measure in place even before the latest bo…