Sewerage upgrades will help solve Kariba weed problem

Pauline Lourens and Ken Gie, Gardag Committee:

The Garden Route Dam is George's sole source of water. For the sake of our community's health and safety as well of the survival of the town - it is imperative that we guard against polluting this life-giving asset.

The proliferation of Kariba weed on the Garden Route Dam needs to be urgently addressed by all our local authorities, but more specifically by the George Municipality. The Garden Route Dam Action Group (Gardag) is concerned that the health and future stability of our drinking water source are under threat.

The Kat River which feeds into the dam has for many years been subjected to sewage outfalls from an ageing sewage system. The weed thrives on this.

The Kariba weed is being sprayed to combat its spreading. But this is merely treating the symptoms. A more permanent way of removing Salvinia molesta (orinally from Brazil) has to be found for this noxious weed to be eradicated. Failing to do so will result in oxygen depletion in our drinking water source, causing fish and all live organisms to die. After being sprayed the plant sinks to the bottom and starts to rot, forming a thick sediment which results in gaseous emissions that may eventually lead to eutrophication (“The process of water becoming overly enriched with minerals and nutrients which induces excessive growth of algae and oxygen depletion” - Wikipedia). This is unhealthy and detrimental to the environment.

Gardag urges the George Municipality to urgently investigate the root causes of the proliferation of this invasive species and act decisively.

There is a strong indication that the weed spreads from the Kat River. The Kat River has been polluted for many years by the overflowing and inadequately maintained sewerage line which routes through

Fernridge and Denneoord as well as Bergsig and Eden. The sewer line was supposed to be systematically upgraded as finances allowed. But it seems that this process has come to a halt? Last year George Herald carried two reports by Michelle Pienaar detailing problems with sewage / effluent overflows in Denneoord. This is probably the tip of the iceberg.

Can we continue to ignore the health risks to the communities living along the Kat River? Can we overlook the dangers of eutrophication which can result in the entire dam becoming a slimy green entity?

Over the last six years, canoeists and cyclists reported the annual re-emergence of the Kariba weed in the Kat River and in the dam. Effluent is rich in nutrients and this is what the weed thrives on. If the municipality upgrades the (Denneoord/Fernridge/Bergsig) sewage line thereby eliminating pollution, it will obviate the need to buy expensive chemicals to combat this weed as the latter will disappear.

Ignoring this health issue, or refusing to release river / dam water samples as well as denying this ongoing issue exists - will do nothing to ensure a healthy water supply. Now that Georgians are more actively exercising around the dam they are distressed to note that even here in the beautiful outdoors they have to worry about the future of their drinking water source.

The officials who are supposedly tasked with looking after our main drinking water source are shortsighted. They too have to drink this water and so will their grandchildren long after they have retired. With the new mayor and municipal manager in place, we are hopeful that an upgrade is on the cards? George Municipality responds:

George Municipality takes note of the letter written and confirms that monthly monitoring of all rivers on which municipal infrastructure is situated, remains in place. The upgrading of pipelines and portions of the Eden Pump Station over the past year have improved the situation.

Sewage spillages are not uncommon occurrences and municipalities, who are also water services authorities, are required to plan for such incidents accordingly. Procedures are already underway to eradicate the

Kariba weed and the Department of Water and Sanitation, Garden Route District Municipality and Breede-Gouritz Catchment Management Agency will be notified and consulted for long-term solutions.

Our Community Services Department has also indicated that they are reviewing possible alternatives to spraying, which is acknowledged to be a short-term solution.

Over the last six years, canoeists and cyclists reported the annual re-emergence of the Kariba weed in the Kat River and in the dam.