Where an adequate public storm main is available at the plat boundary, the subdivider shall construct a storm sewer system and connect with such storm sewer main. If such storm sewer systems are not accessible, drainage channels with easements of adequate width shall be provided, by the subdivider and approved by the Village Engineer and Planning Commission. Paved gutters or storm sewers shall be required if velocities of flow are greater than specified by the Village Engineer or cause destructive erosion. Storm drainage, including drain-tile around basements, shall not be permitted to discharge into any sanitary sewer facility.