Windsor CA, faced with a costly problem of where to store treated wastewater, is now sending it by pipeline to The Geysers, one of the oldest and biggest geothermal power plants in the nation. This saves the city millions and helps the Geysers as well. The water is injected deep into the earth where it heats up and is then used by the geothermal plant.
This is exactly the kind of thing that will be happening more often as public and private entities around the globe realize that their water security is fading. And the smarter the city or company, the sooner they will adapt.