California Code, Public Contract Code - PCC § 20341

(a) Contracts for construction in excess of fifty thousand dollars ($50,000) shall be awarded to the lowest responsible bidder submitting a responsive bid after competitive bidding, except in emergency declared by the vote of two-thirds of the membership of the board.  If the expected construction contract exceeds one thousand dollars ($1,000) and does not exceed fifty thousand dollars ($50,000), the board shall seek a minimum of three quotations, either written or oral, that permit prices and other terms to be compared, and the board shall award the contract to the bidder who submitted the lowest quotation.

(b) If no bids are received, the project may be performed by a negotiated contract.