Accounting for California’s Water

Understanding California’s water balance sheet—how much there is, who has claims to it, and what is actually being “spent”—is key to effectively managing the state’s limited water supply in support of a healthy economy and environment. The latest drought has spotlighted serious gaps and fragmentation in California’s water accounting system.

In this report, we identify gaps in California’s water information systems. We recommend that the state adopt an overarching goal of modernizing its water accounting, and that key state agencies—supported by an oversight committee of key stakeholders and independent experts—develop and adopt a common accounting framework. We outline a dozen priority actions to strengthen water accounting by: improving measurements and estimates of water availability and use; firming up legal claims on water rights and water reserved for the environment; establishing protocols, standards, and models for transparent water accounting at all levels across the state; and making water information more available and accessible to water managers, water users, policymakers, and the public.