(a)      Any contract or commitment hereafter entered into by the Commission with the United States of America or with any bureau or agency thereof, or with the National Capital Planning Commission pursuant to the authority of this title, and any amendment of a preexisting contract or commitment, shall be subject to the conditions and limitations of this section insofar as the contract or commitment refers to obtaining the advances authorized by subparagraphs (a) and (b) of § 1 of Public Law No. 284 of the 71st Congress, as amended, for the purpose of acquiring park lands in the metropolitan district.

      (b)      Any contract or commitment with respect to the acquisition of park lands within the metropolitan district, entered into by the Commission prior to the year 1947 pursuant to any act of the General Assembly of Maryland enacted prior thereto, is validated and approved and declared to be binding, in accordance with its terms, upon the State of Maryland, the Commission, and Montgomery County or the County Commissioners of Prince George's County.

      (c)      If the Commission desires to amend any contract or commitment with respect to the acquisition of park lands within the metropolitan district (other than supplementary agreements hereinafter mentioned having reference to the acquisition of particular units of park land comprising portions of a general park plan theretofore approved by the County Council of Montgomery County or County Commissioners of Prince George's County), the amendment is not binding upon the State of Maryland, the Commission, Montgomery County or County Commissioners of Prince George's County unless it has been ratified and approved by the County Council of Montgomery County and the County Commissioners of Prince George's County.

      (d)      If the Commission desires to enter into a new basic or underlying agreement with the United States of America or with any agency or bureau thereof or with the National Capital Planning Commission for the purpose of adopting a general or revised park plan of park lands to be acquired in the metropolitan district and for the purpose of outlining the method of financing the acquisition of any park lands, the new basic or underlying agreement may not be binding upon the Commission or upon the State of Maryland or upon Montgomery County or the County Commissioners of Prince George's County until it has been approved by the County Council of Montgomery County and the County Commissioners of Prince George's County.

      (e)      Agreements supplementary to any contract or commitment, or amendment thereof, heretofore or hereafter entered into by the Commission, and having reference (1) to the acquisition of particular units of land in the metropolitan district comprising portions of a general park plan adopted in any such contract or commitment and also (2) prescribing the details incident to financing the acquisition, may be entered into by the Commission with the United States of America or any agency or bureau thereof or with the National Capital Planning Commission upon the conditions hereinafter in this section set forth.

      (f)      Each supplementary agreement shall first be submitted for approval to the County Council of Montgomery County or the County Commissioners of Prince George's County, depending upon the location of the unit or units of park land involved. The respective county shall approve the agreement, if it finds that (1) the boundaries of the unit of land to be acquired pursuant to the supplementary agreement are within the general park plan adopted by the contract or commitment to which the agreement is supplementary; and (2) the Commission will be able to meet the obligations to be incurred by it in the acquisition, including the payment of interest on the obligations, from the proceeds of the tax authorized and directed to be levied in that portion of the metropolitan district lying within Montgomery County or from the proceeds of the tax authorized and directed to be levied in that portion of the metropolitan district lying within Prince George's County. In determining whether the Commission will be able to meet the obligation from the proceeds of the taxes, the County Council or County Commissioners shall compute the proceeds upon the assessable basis of those portions of the metropolitan district lying within Montgomery and Prince George's counties, respectively, for the fiscal year in which approval is sought and upon the assumption that the entire tax levied will be collected so long as any of the obligations to be incurred pursuant to the supplementary agreement are outstanding and unpaid.

      (g)      The approval by the County Council of Montgomery County or of the County Commissioners of Prince George's County may be given by simple resolution authorizing the president of the Council to endorse the approval of the county on the supplementary agreement and to execute a guarantee by this title.

      (h)      In approving either (1) basic or underlying agreements or amendments thereto and not relating to acquisition of a particular unit of park lands, or (2) supplementary agreements supplementary to basic or underlying agreements and relating only to acquisition of particular units of park lands, no legislative action by the County Council of Montgomery County is necessary.