The salary of the stream patroller shall be borne by the water users receiving the benefits and shall be paid to the county or counties in the following manner:
The county or counties may assess each water user for his or her proportionate share of the total stream patroller expense in the same ratio that the amount of water diverted by him or her bears to the total amount diverted from the stream during each season, on an annual basis, to recover all such county expenses. The stream patroller shall keep an accurate record of the amount of water diverted by each water user coming under his or her supervision. On the first of each month the stream patroller shall present his or her record of water diversion to the county or counties for the preceding month. Where the water users are organized into an irrigation district or water users' association, such organization may enter into an agreement with the county or counties for direct payment to the stream patroller in order to minimize administrative costs.