Cal. Gov. Code § 27707.1
The boards of supervisors of two or more counties may authorize their respective public defenders to enter into reciprocal or mutual assistance agreements whereby a deputy public defender of one county may be assigned on a temporary basis to perform public defender duties in the county to which he has been assigned in actions or proceedings in which the public defender of the county to which the deputy has been assigned has properly refused to represent a party because of a conflict of interest or because of some other present inability.
For purposes of this section, the term "present inability" shall include a lack of personnel, lack of expertise, or lack of other resources by the local office.
Whenever a deputy public defender is assigned to perform public defender duties in another county pursuant to such an agreement, the county to which he is assigned shall reimburse the county in which he is regularly employed in an amount equal to the portion of his regular salary for the time he performs public defender duties in the county to which he has been assigned. The deputy public defender shall also receive from the county to which he has been assigned the amount of actual and necessary traveling and other expenses incurred by him in traveling between his regular place of employment and the place of employment in the county to which he has been assigned.
A board of supervisors may also authorize the reciprocal or mutual assistance agreements provided for in this section with the State Public Defender.
Ca. Gov. Code § 27707.1