Phoenix is about to get less water from the Colorado River. That does not mean 1.7 million residents are about to turn on their faucets and find them dry. The city has spent decades preparing for this moment, building pipelines, storing water underground and maintaining access to other rivers.
The harder question is what comes next. Phoenix is entering an era in which keeping water reliable requires projects measured not in millions of dollars, but billions.
The city’s current six-year drinking-water capital program totals more than $9.1 billion. About $1 billion of that is specifically devoted to Colorado River resilience, alongside billions more for treatment plants, pipelines, pumps and storage…