California Code, Revenue and Taxation Code - RTC § 5086

(a) The portion of the current taxes and any penalties and costs that are allocable to the part of the fiscal year that ends on the day before the date of apportionment shall be paid through escrow at the close of escrow or from the award in eminent domain.

(b) The portion of the current taxes and any penalties and costs that are allocable to the part of the fiscal year that begins on the date of apportionment shall be canceled and are not collectible either from the person from whom the property was acquired or from the public entity that acquired the property.

(c) If the amount of taxes or special assessment liens is unknown, the portion of the current taxes attributable to the period of the fiscal year that ends on the day before the date of apportionment shall be ascertained by the auditor on a pro rata basis of the previous year's taxes, and shall be paid to the tax collector. The auditor shall adjust the assessment roll and the tax charge accordingly.