Long-term Colorado River rescue plan at an impasse? It's north vs. south in the West

Negotiations between northern and southern states have foundered between two sides.

Lower Basin states would agree to take 1.5 million acre-feet of water less from shrinking river each year .

Upper Basin states have for years taken twice as much as their northern neighbors.

Federal officials say the chances of Lake Mead falling below critical levels to just 4% .

Report shows 860,000 acre-feet of Colorado River water lost to evaporation annually between 2017 and 2021 from Lake Mead to border with Mexico .

An acre-foot is enough to supply about three California households in dry years .

The Lower Basin states have been using more than their annual allocation of 7.5 million acre feet .

Federal and state officials are pushing to finalize a voluntary agreement by the end of this year .

They have until Dec. 31, 2026 , before current operational guidelines for the river system expire.

The clock is ticking.