(a) Easements across lots or centered on rear or side lot lines shall be provided for utilities where necessary and shall be at least sixteen feet wide. Proper continuity for utilities shall be maintained from block to block.
(b) Where a subdivision is traversed by a watercourse, drainageway, channel or stream, there shall be provided a storm water easement or drainage right of way conforming substantially to the lines of such watercourse, and such further width or construction, or both, as will be adequate for proper drainage. Parallel streets or parkways may be required in connection therewith.