On Thursday, Utah hit pause on a pipeline project that could force Arizona to limit how much water it sends to growing cities across the Valley. 

The proposed Lake Powell Pipeline would divert billions of gallons of water from the Colorado River to St. George, Utah. Century-old agreements entitle Utah to the water, but critics worry the pipeline would deplete Lake Powell even more than drought and climate change already have.

Arizona joined five other states earlier this month to urge the U.S. Interior secretary not to fast-track the pipeline. Their letter was just one of 14,000 comments that have poured in on a draft environmental impact statement.

Utah now says it needs more time to review the comments and has asked the federal government to delay its approval process.