Penal Code § 4118
ARTICLE 1. County Industrial Farms
The legislative body of any incorporated city located in a county which has established an industrial farm or industrial road camp may adopt and forward to the board of supervisors a certified copy of a resolution stating that the city desires to have its prisoners cared for on the industrial farm or camp and agrees to pay therefor quarterly at a rate per prisoner per day, which rate shall be set forth in the resolution.