Cal. Gov. Code § 51063

If any land or a portion thereof as to which any city or county has accepted an open-space easement is thereafter sought to be condemned for public use and the city or county received the easement as a gift without the payment of any compensation therefor, the easement shall terminate as of the time of the filing of the complaint in condemnation as to the land or portion thereof sought to be taken for public use, and the owner shall be entitled to such compensation for the taking as he would have been entitled to had the land not been burdened by the easement.