(A) Every lot must contain a suitable building site and be able to conform to the requirements of the building and zoning code for the erection and location of building structures.
(B) No land will be approved for subdivision which is subject to periodic flooding or which contains extremely poor drainage facilities. However, if the subdivider agrees to make improvements which will, in the opinion of the city engineer, make the area completely safe for residential occupancy and provide adequate drainage, the preliminary plan for subdivision may be approved.
('69 Code, App. B, § 5.5)