The Knysna Municipality is working on a Stormwater Management Policy aimed at reducing erosion and pollution, as well as looking at how groundwater can be recharged.
Levael Davis, Mayoral Committee Member for Technical Services, says the new policy will address illegal connections and set targets for different development types.
According to Davis illegal stormwater connections remain a serious concern for the municipality. “When it rains up to seven times more water runs into the sewers than should. The calculations are done taking the amount of water released from the Water Treatment Works during these wet periods into account. Perfectly clean water is then treated along with the sewerage, causing overflows of the sewerage system,” he adds.
Protecting natural ecosystems
The stormwater system was also identified as one of the main sources of pollution into the estuary. The cause is mainly as a result of illegal sewer connections that feed into the stormwater systems, as well as other unlawful connections to stormwater, such as swimming pool backwash systems.
“A fundamental principle of the policy is that all developments should be done responsibly, whether done by a person or body, privately, by a business or an organ of state,” Davis explained.
“The developer should ensure that the development does not adversely impact on present and future communities, and on natural ecosystems. This is in line with our own by-laws and the principles of sustainable development.”
Stromwater a resource not a nuisance
Sue Swain, Executive Director of BioWise, a local NGO that promotes the practice of biomimicry and looking after Greater Knysna’s natural resources, said that residents and developers alike should be persuaded to think differently about stormwater.
“Stormwater is a resource, not a nuisance. Residents should take initiative and harvest at least the rain from the roof and storing this in tanks.”
Swain adds that stormwater from road and other hard surfaces should not be ignored. “This water is traditionally channelled into stormwater drains that discharge directly into the estuary. What we should be doing is learning to ‘plant’ the rain, to re-direct this run-off. The very worst thing one can do is to connect rain from the roof to the sewer,” she explains.
“The Municipal Water and Sanitation bylaw is clear that no rain or storm water may be discharged in a drainage solution -it is not only illegal, but potable rainwater is turned into filthy sludge and overloads the wastewater treatment works in the process,” she adds.
Davis concludes by saying that the Municipality is working alongside Swain to see how they can make better use of stormwater.