The seven states that depend on the Colorado River have missed a Jan. 31 federal deadline for reaching a regionwide consensus on how to sharply reduce water use, raising the likelihood of more friction as the West grapples with how to take less supplies from the shrinking river.

In a bid to sway the process after contentious negotiations reached an impasse, six of the seven states gave the federal government a last-minute proposal outlining possible water cuts to help prevent reservoirs from falling to dangerously low levels, presenting a unified front while leaving out California, which uses the single largest share of the river.