(A) The responsibility of the developer shall extend to the provision of adequate off-site drainage facilities and improvements to accommodate the full effects of the development of said property.
(B) When the developer certifies by affidavit that a bona fide attempt to acquire property rights to meet off-site drainage requirements was not successful, the city may assist at its discretion in the acquisition of necessary property rights to provide for the construction of off-site drainage improvements. In such cases, the developer shall make adequate guarantees that he will stand the full cost of acquiring said property rights and constructing the off-site improvements and facilities.