California Code, Public Contract Code - PCC § 20736

(a) All construction authorized under this article that exceeds two thousand five hundred dollars ($2,500) shall be awarded upon competitive bidding.  Notice of the proposed letting of such a contract shall be published pursuant to Section 6066 of the Government Code in a newspaper of general circulation in the district or, if there is none, of general circulation in the county, the first publication to be at least two weeks prior to the opening of bids.  The notice inviting bids shall set a date for the opening of bids.  The contract shall be awarded to the lowest responsible bidder.  In its discretion, the board may reject any bids presented and readvertise.  If two or more bids are the same and the lowest, the board may accept the one it chooses.  If no bids are received, the board may have the work done directly by purchasing the materials and hiring the labor.

(b) If all bids are rejected, the board may adopt a resolution, by four-fifths vote, declaring that the work can be performed more economically by hiring day labor, or that the materials or supplies can be furnished at a lower price in the open market, and may have the work done in the manner stated in the resolution in order to take advantage of this lower cost.

(c) If there is an emergency, the board may, by four-fifths vote adopt a resolution declaring that the public interest and necessity demand the immediate expenditure of public money to safeguard life, health, or property, and expend any sum required in the emergency without submitting the expenditure to the bidding procedure set forth.  If notice for bid to let contracts will not be given, the board shall comply with Chapter 2.5 (commencing with Section 22050).

(d) The board may negotiate with the government of the United States or any department or agency thereof, the state or any department or agency thereof, or any local public agency for the purpose of assisting the district in the performance of any of the work authorized by this article and, without advertising for bids, may cause the district to contribute to the United States, the State of California, or any local public agency all or any portion of the estimated cost of any work authorized by this article which is to be done by or under contract with the United States, the State of California, or any local public agency.