California Code, Public Contract Code - PCC § 20150.1

(a) Notwithstanding any other law, except as provided in subdivision (b) or (c), every county, whether general law or charter, containing a population of less than 500,000 shall employ bidding procedures on public projects as provided in this article.  This article shall be liberally construed to effect its purposes.  In the event of conflict with any other provision of law relative to bidding procedures, the provisions of this article shall apply.

(b) Every county, whether general law or charter, containing a population of less than 500,000 is authorized to participate in the Uniform Public Construction Cost Accounting Act under Chapter 2 (commencing with Section 22000) of Part 3 of Division 2.

(c) A county, whether general law or charter, containing a population of less than 500,000 may award individual annual contracts as provided in Section 20128.5.