The question then arises as to whether private insurance companies will continue to insure development on flood plains liable to flooding. It is also of concern that this 9.2 hectare retarding basin is supposed to provide the only public open space for this development. Stormwater, oil and waste water from car washing will run directly into a pond to remove nutrients and phosphorus. The water, after initial treatment will flow into other ponds before entering drains and finally, Mordialloc Creek. The entire 9.2 HA retarding basin could at times of severe storm events be under water because of the overflow from the Woodlands Industrial Estate as well as stormwater on-site.
Mosquito species use the wetlands and ponds as breeding grounds.
The close proximity of the polishing ponds to housing raises the question of effective mosquito control. Whoever ultimately becomes responsible for maintaining the wetlands will need to be vigilant in removing excessive weed growth, a potential breeding ground for mosquitoes. If the wetlands become contaminated with weed killers such as glyphosate used in suburban gardens, then the frogs, which will be relied upon to control mosquito breeding, won't survive and the wetlands will indeed become a health hazard. Wetland systems offer a low technology approach to controlling pollution although they do require a large area of suitable land and if they are used, proponents must understand and accept the risk of failure and unsatisfactory performance Care is required when it is proposed to use wetland filter systems to control the quality of urban runoff. Urban runoff is intermittent and of variable quality, containing pollutants such as sediment, organic matter, bacteria, nutrients, metals, pesticides and hydrocarbons.