Cal. Gov't Code § 39901
A city whose limits include or bound upon a harbor, bay, estuary, or other navigable body of water may:
(c) Do any thing necessary or convenient to the establishment, improvement, conduct, and maintenance of a harbor, and in furtherance of commerce and navigation.
This section does not affect or limit a person’s use and enjoyment of property rights, nor grant a city the right to destroy, injure, impair, or interfere with any private or quasi-public property or property rights, leasehold, or otherwise, or to the use and enjoyment of the property.