You can’t understand water in the west without understanding urban growth patterns. They’re joined at the hip. Here, in a single graph, is the explanation for the Vegas announcement yesterday that its two main water agencies are laying off 7.5 percent of their staff:

Henry Brean explained it thus:

The Southern Nevada Water Authority and the Las Vegas Valley Water District began laying off 101 full-time workers Wednesday as the wholesale water supplier and its largest member utility shift their focus from chasing growth to maintaining existing infrastructure.

“At both the district and the authority for the last 20 years or more, we worked to install the plumbing that makes big parts of our community possible,” said John Entsminger, general manager of both agencies.

Today that mission has changed from “growth-support” to one focused on operations, maintenance and customer service, he said.