Harbors and Navigation Code § 4120

Whenever the improvement, development or protection of any such harbor, bay, inlet or other arm of the sea is completed and the commission created under this chapter ceases to exist, then the management and control of the harbor in so far as it has been improved, developed or protected under this chapter passes to, and vests in the board of supervisors of the county. The future cost and expense of the maintenance of the harbor is a charge upon the county.