The subdivider shall construct all necessary facilities including underground pipe, inlets, catch basins or open drainage ditches, as determined by the Municipal Engineer, to provide for adequate disposal of subsurface and surface water and maintenance of natural drainage courses. The velocity of flow in an open ditch shall not exceed four feet per second in soil ditches or six feet per second in turf gutters. Paved gutters will be required if velocities of flow are greater than those specified or if it is otherwise likely that destructive erosion will result. Drainage ditches shall not be permitted to discharge into any sanitary sewer facility. Residential building lots shall be so located or graded to provide surface drainage away from the building to a suitable water disposal system. In no instance shall buildings or lot-forming block natural waterways, or shall grading or elevation of lots cause a water problem on neighboring lots.