Cal. Gov. Code § 6953
The Legislature further declares that the acquisition of interests or rights in real property for the preservation of open spaces and areas constitutes a public purpose for which public funds may be expended or advanced, and that any county or city may acquire, by purchase, gift, grant, bequest, devise, lease or otherwise, the fee or any lesser interest, development right, easement, covenant or other contractual right necessary to achieve the purposes of this chapter. Any county or city may also acquire the fee to any property for the purpose of conveying or leasing said property back to its original owner or other person under such covenants or other contractual arrangements as will limit the future use of the property in accordance with the purposes of this chapter.
Ca. Gov. Code § 6953