The latest USGS data on water use by U.S. municipalities shows a continued decline, despite a growing population. This not just a decline in per capita use, though it is that. But per capita use continues to drop faster than population is rising in most areas. Brett Walton has a nice summary of the findings, and the full datasets for 2015 are here (and here for past datasets, for you enterprising Water Resources Program students who want to dig in).

But, importantly, as Walton points out, this is not happening everywhere:

According to the USGS report, which uses data from state agencies and water utilities, per person water use increased in the states of Alaska, Colorado, Idaho, Louisiana, Utah, Virginia, Wisconsin, and Wyoming.

Most of these states are in the American West, and three are in the upper basin of the Colorado River, where there is strong debate about whether to increase water withdrawals from the shrinking river.

This is interesting. In the Lower Colorado River Basin – California, Arizona, and Nevada – water use is down. With the exception of New Mexico, in the Upper Basin it’s heading up.

Some highlights:

• New Mexico, population rose 2 percent from 2010 to 2015, while water use dropped 10 percent.
• Albuquerque, population rose 4.6 percent while water use dropped 10.8 percent.
• Maricopa County (greater Phoenix): population up 9.3 percent, water use down 3.6 percent.
• Clark County, NV (greater Las Vegas): population up 7.4 percent, water use down 1.6 percent.
• Los Angeles County: Population up 9.7 percent, water use down 8.4 percent.
• San Diego: Population up 14.1 percent, water use down 14.5 percent.
• Salt Lake County: Population up 7.4 percent, water use up 33.3 percent
• Washington County, Utah (St. George area, where Utah wants to build the new Lake Powell Pipeline to remove water from the Colorado River): Population up 12.4 percent, water use up 11.7 percent, and per capita water use a hefty 318 gallons per person per day (more than double Albuquerque’s).