California Code, Penal Code - PEN § 4115.5

(a) The board of supervisors of a county where adequate facilities are not available for prisoners who would otherwise be confined in its county adult detention facilities may enter into an agreement with the board or boards of supervisors of one or more nearby counties whose county adult detention facilities are adequate and are readily accessible from the first county to permit commitment of misdemeanants, and any persons required to serve a term of imprisonment in county adult detention facilities as a condition of probation, to a jail in a county having adequate facilities that is a party to the agreement.  That agreement shall make provision for the support of a person so committed or transferred by the county from which he or she is committed.  When that agreement is in effect, commitments may be made by the court and support of a person so committed shall be a charge upon the county from which he or she is committed.

(b) This section shall become operative on July 1, 2021.