Where it is necessary to make changes in the contour of any land proposed to be subdivided, developed or changed by grading, or excavating or by the removal or destruction of the natural topsoil, trees or other vegetative covering thereon, the same shall be accomplished only after the owner or his agent has submitted to the City Planning commission for approval a plan for the surface water, erosion and sedimentation control and such plan has been approved. Such plan shall incorporate the following controls:
(1) All surface water shall have drainage ditch outlets of a temporary nature provided for it during construction and shall be approved by the City Engineer. No exposed area that will pond a great amount of water overnight will be permitted.
(2) No more than thirty percent of the total area shall be exposed at any one time during construction unless proper measures are taken to prevent erosion, siltation and sedimentation.
(3) No area shall be exposed any longer than necessary to recontour. Temporary vegetation and/or mulching shall then be applied for protection during the development.
(4) No area shall be allowed to go into the winter season without vegetative cover on critical areas as determined by the City Engineer. Such areas shall be seeded by Oct. 1.
(5) Sediment basins (debris basins, desilting basins or silt traps) shall be installed and maintained to remove sediment from run-off waters for land undergoing development.
(6) Permanent final vegetation and drainage structures shall be installed as soon as grading is completed.
(7) The development shall be fitted to the topography and soils so as to create the least erosion potential.
(8) Whenever feasible, natural vegetation shall be retained and protected.