Cal. Water Code § 81336.5

(a) No incompatibility of office shall result from an elected official serving on the board of the agency and on the governing board of a member public entity. A board member may vote on contracts or other matters involving the member public entity he or she represents.
(b) The agency may enter into a contract with California Water Service Company only if both of the following requirements are met:
1. (1) The director appointed by the Board of Supervisors of San Mateo County does not participate in a vote on the contract.
2. (2) The contract is approved by the affirmative vote of a majority of all members of the board other than the director appointed by the Board of Supervisors of San Mateo County.
(c) The agency may enter into a contract with Stanford University only if both of the following requirements are met:
1. (1) The director appointed by the Board of Supervisors of Santa Clara County does not participate in a vote on the contract.
2. (2) The contract is approved by the affirmative vote of a majority of all members of the board other than the director appointed by the Board of Supervisors of Santa Clara County.
(d) A contract approved pursuant to the requirements of this division does not constitute a violation of Section 1090 or 1097 of the Government Code, nor is it void or voidable pursuant to Section 1092 of the Government Code.