Digital tools have expanded the ability of governments, companies and nonprofits to measure the uses of California water in detail, and thus build more water-efficient products, boost water conservation, and replace expensive and inefficient infrastructure.
But the abundance of water data effectively makes every piece of land and every drop of water in California the subject of measurement—and conflict.
The data also exposes the fragmentation and deficiencies of California's system of water management.
The state's new conservation requirements add to the stakes of arguments over data. As Californians struggled to save every drop during the recent five-year drought, the state for the first time imposed mandatory restrictions on water use—requiring that 400 local water agencies figure out how to reduce usage by 25 percent in 2015.
That shift, following 2009 legislation setting a goal of reducing urban per capita water use by 20 percent by 2020, is changing the way Californians fight over water—away from historic battles over dams, and toward new contests over maximizing the water we already have.