To carry out the purposes of this chapter, any public body may (i) acquire by purchase, gift, devise, bequest, grant or otherwise title to or any interests or rights of not less than five years’ duration in real property that will provide a means for the preservation or provision of open-space land and (ii) designate any real property in which it has an interest of not less than five years’ duration to be retained and used for the preservation and provision of open-space land. Any such interest may also be perpetual. The use of the real property for open-space land shall conform to the official comprehensive plan for the area in which the property is located. No property or interest therein shall be acquired by eminent domain by any public body for the purposes of this chapter; however, this provision shall not limit the power of eminent domain as it was possessed by any public body prior to the passage of this chapter.