California Code, Health and Safety Code - HSC § 117025

It is unlawful for the owner, tenant, lessee, or occupant of any houseboat or boat intended for or capable of being used as a residence, house, dwelling, or habitation, or agent of the owner, tenant, lessee, or occupant to moor or anchor it or permit it to be moored or anchored in or on any river or stream, the waters of which are used for drinking or domestic purposes by any city, town, or village, within a distance of two miles above the intake or place where the city, town, or village water system takes water from the river or stream. This section does not apply to the mooring or anchoring of a houseboat when necessary, during transportation, for a period of not longer than one day.