Cal. Wat. Code § 21189
The board may adopt and carry into effect a contract or contracts of group insurance, a system of group annuities, a system of medical and hospital service, or any two or more of these, for the benefit of such of the officers, including directors, and employees of the district as accept the same and who have authorized the board to make any necessary deductions from their compensation for the payment of a portion of the premium thereon. Contracts of group insurance, systems of group annuities, or systems of medical and hospital service, which include benefits to dependents of officers and employees or retired officers and employees are contracts of group insurance, systems of group annuities, or systems of medical and hospital service for the benefit of officers and employees for the purposes of this section. The board may make such deductions, and may pay the remainder of such premiums from any funds of the district not required to be devoted to a specific purpose. The board may pay such portion of the premiums thereon or attributable thereto as it determines to be advisable. The board may arrange or contract for a contract or contracts of group insurance, a system of group annuities, or a system of medical and hospital service, or any two or more of these, with any private or public agency, nonprofit membership corporation, or any insurance company or agent authorized by or pursuant to law to transact such business within this State. Nothing in this section shall be construed to limit the provisions of Chapter 250, Statutes of 1939, or of Section 1157 of the Government Code insofar as such provisions apply to districts and officers and employees thereof.
Ca. Water Code § 21189