(1) Subject to the provisions of subsection (2), when considered in the best interests of the county, the board may:
(a) enter into agreements for the pooling of acreage with others for unit operations for the production of oil or gas or both and for the apportionment of oil or gas royalties or both on acreage or other equitable basis; and
(b) modify existing leases and leases hereafter entered into with respect to delay rentals, delay drilling penalties, and royalties in accordance with such pooling agreements and such unit plans of operation.
(2) Such agreements shall not change the percentages of royalties to be paid to the county from the percentages as fixed in its leases.