Among the centralized options for augmenting potable water supplies, potable reuse is preferable to interbasin water transfers for several reasons (25): (i) Interbasin water transfers reduce the water available at the source for critical ecosystems and agricultural production; (ii) transporting water over long distances can be energyand
carbon-footprint–intensive; and (iii) the water transmission systems are vulnerable to disruption by natural and
human-made disasters, such as earthquakes and acts of terrorism. All three problems are evident in California, where the southern part of the state has long relied on water imported from sources located hundreds of kilometers to the east and north. In 2001, an estimated 4% of