Cal. Water Code - WAT § 1840. Section 1840.
(a)
(1)
Except as provided in subdivision (b), a person who, on or after January 1, 2016, diverts 10 acre-feet of water per year or more under a permit or license shall 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. The measurements shall be made using the best available technologies and best professional practices, as defined in Section 5100, using a device or methods satisfactory to the board, as follows:
(A)
A device shall be capable of continuous monitoring of the rate and quantity of water diverted and shall be properly maintained. The permittee or licensee shall
provide the board with evidence that the device has been installed with the first report submitted after installation of the device. The permittee or licensee shall provide the board with evidence demonstrating that the device is functioning properly as part of the reports submitted at five-year intervals after the report documenting installation of the device, or upon request of the board.
(B)
In developing regulations pursuant to Section 1841, the board shall consider devices and methods that provide accurate measurement of the total amount diverted and the rate of diversion. The board shall consider devices and methods that provide accurate measurements within an acceptable range of error, including the following:
(i)
Electricity records dedicated to a pump and recent pump test.
(ii)
Staff gage calibrated with an
acceptable streamflow rating curve.
(iii)
Staff gage calibrated for a flume or weir.
(iv)
Staff gage calibrated with an acceptable storage capacity curve.
(v)
Pressure transducer and acceptable storage capacity curve.
(2)
The permittee or licensee shall maintain a record of all diversion monitoring that includes the date, time, and diversion rate at time intervals of one hour or less, and the total amount of water diverted. These records shall be included with reports submitted under the permit or license, as required under subdivision (c), or upon request of the board.
(b)
(1)
The board may modify the requirements of subdivision (a) upon finding either of the
following:
(A)
That strict compliance is infeasible, is unreasonably expensive, would unreasonably affect public trust uses, or would result in the waste or unreasonable use of water.
(B)
That the need for monitoring and reporting is adequately addressed by other conditions of the permit or license.
(2)
The board may increase the 10-acre-foot reporting threshold of subdivision (a) in a watershed or subwatershed, after considering the diversion reporting threshold in relation to quantity of water within the watershed or subwatershed. The board may increase the 10-acre-foot reporting threshold to 25 acre-feet or above if it finds that the benefits of the additional information within the watershed or subwatershed are substantially outweighed by the cost of installing measuring devices or employing methods for
measurement for diversions at the 10-acre-foot threshold.
(c)
At least annually, a person who diverts water under a registration, permit, or license shall report to the board the following information:
(1)
The quantity of water diverted by month.
(2)
The maximum rate of diversion by months in the preceding calendar year.
(3)
The information required by subdivision (a), if applicable.
(4)
The amount of water used, if any, for cannabis cultivation.
(d)
Compliance with the applicable requirements of this section is a condition of every registration, permit, or license.