Bruce Finley in the Denver Post tallies up another western city cutting municipal water use, demonstrating that, for city water users, this is a tractable problem:

Water-saving efforts already have dropped metro Denver residents’ overall average daily usage to 85 gallons, down from 104 gallons in 2001.

Only one city better than Denver in Finley’s review of residential water use:

Albuquerque at 70 gallons a day.

Note that Finley’s talking here about withdrawals, and doesn’t get into the extent to which a portion of cities’ indoor water is reused after treatment, with the exception of a nod toward the way Las Vegas handles its wastewater.