Water rights: measurement of diversion.

(1) Existing law defines various terms applicable to the Water Code. This bill would define "water year," unless otherwise specified, to mean the 12-month period beginning October 1 and ending September 30. (2) Existing law requires a person who diverts 10 acre-feet or more of water per year under a permit or license to install and maintain a device or employ a method capable of measuring the rate of direct diversion, rate of collection to storage, and rate of withdrawal or release from storage. Existing law requires the measurements to be made using the best available technologies and best professional practices using a device or methods satisfactory to the State Water Resources Control Board, as specified in regulations adopted by the state board. Existing law requires a permittee or licensee to maintain a record of all diversion monitoring, as provided, and to include those records with annual reports required to be submitted to the state board. Existing law authorizes the state board to modify these requirements if the state board finds that strict compliance with these requirements is infeasible, is unreasonably expensive, would unreasonably affect public trust uses, or would result in the waste or unreasonable use of water, or that the need for monitoring and reporting is adequately addressed by other conditions of the permit or license. This bill, among other things, would clarify existing law that a diverter, as defined, diverting 10 acre-feet or more of water per year is subject to these water diversion measurement, recording, and reporting requirements, as specified. This bill would require the state board to develop and administer a study to determine the ability of evapotranspiration alone, or in combination with other methodologies, to provide the information needed to monitor water diversions, as specified. The bill would require the state board to provide the Legislature with a report documenting the study, its results, and the findings of an independent review on or before January 1, 2028.