Maintenance of parking areas. Parking areas shall be graded, surfaced and drained to the extent necessary to prevent dust, erosion, or water flow across streets or adjoining properties. All off-street parking spaces shall be marked to indicate their location and shall conform to the requirements of the Federal Americans with Disabilities Act, providing an adequate number of sized, marked and signed spaces. All off-street parking spaces shall be kept free of potholes, weeds, trash and debris.