(a) Where the county government has already established a suburban park community hereunder, then, the commission may, upon its own motion, and without having received a request from the county government, and without a petition having been filed, proceed to hold a public hearing on the question whether the area included in the suburban park community should be enlarged or whether the layout of any park or recreational area therein shall be expanded, improved or altered. Such public hearing shall be held and notice thereof shall be published and posted, and the commission shall make a recommendation, in the manner prescribed by § 626 of this title.

(b) Within 15 days after the receipt by the county government of the recommendation of the commission, as hereinbefore provided, the county government shall meet and determine whether or not it is in the public interest to enlarge such suburban park community and what shall be its boundaries, and whether all the real property included therein will be benefited by such enlargement and by such expansion, improvement or alteration of the layout of the park or recreational area therein. Such improvements may be made and bonds may be issued to finance the cost thereof in the manner and subject to the conditions prescribed in §§ 628-633 and 650 of this title.