California Code, Revenue and Taxation Code - RTC § 2262.2

A local agency or district formed by a city after the effective date of this chapter to take over and perform services theretofore provided by a county service area for the same territory, may adjust, or cause to be adjusted, upwards, its maximum property tax rate in that territory by an amount equal to the tax rate previously levied, or which could have been levied, by the county service area (including any additional levies permitted by Section 2280), had it continued to provide those services for the territory provided that the county service area is no longer empowered to tax or does not tax the territory covered by the city's local agency or district.