Section 3F. Subject to appropriation, the department shall administer a program for the rehabilitation and improvement of Olmsted Parks in cities and towns of the Commonwealth. For the purposes of this section and section 3G the term ''Olmsted Park'' shall mean a municipal park designed by the architectural firm headed by Frederick Law Olmsted and designated by the department as an Olmsted Park. A city or town with an Olmsted Park within its boundaries that desires state assistance to rehabilitate or improve the Olmsted Park may apply in writing for a grant from the Olmsted Park Improvement Fund established in section 3G.