(a) Notwithstanding any other provision of law, every local or regional public agency authorized by law to serve water to the persons or entities within the service area of the agency may sell, lease, exchange, or otherwise transfer, for use outside the agency, either or both of the following:
(1) Water that is surplus to the needs of the water users of the agency.
(2) Water, the use of which is voluntarily foregone, during the period of the transfer, by a water user of the agency.
(b) This chapter does not prohibit or restrict the transfer of water or water rights by local or regional public agencies pursuant to other provisions of law.