By: Jeremy Westgarth-Taylor (Founder of Water Rhapsody Conservation Systems and winner of a WWF Green Trust Award)
Water is in the news again, but never has the situation been as dire as today. Quite simply – Cape Town is out of water. Any new augmentation schemes are not sustainable.
The following are proposed non-sustainable schemes:
- Damming the Lourens River at Somerset West: This will add less than one percent capacity to our beleaguered situation. There are no more rivers that can possibly be dammed to provide any more water for Cape Town.
- Extracting water from the berg by pumping to the Voëlvlei Dam: The well-respected head of the Freshwater Research Unit at UCT, Prof Jenny Day, commented that this was a “no-no”. Already the salinity of the Lower Berg River is rising to unacceptable standards, and any further extraction will make this worse. The situation of the Lower Breede River is equally parlous.
- Desalination of sea water: this is not sustainable as it is too costly on any scale let alone on a large scale. Costly because each kilolitre of water desalinated from sea water will cost more energy than we have got or we likely will get. Desalination costs eight kilowatt hours per kilolitre of desalinated water. Further problems of desalination are that a super saline concentrate is returned back to sea, which turns valleys in the sea into a place where neither plants nor animals can survive.
- Pumping from the TMG (Table Mountain Aquifer): Already we have seen deep boreholes dry up and collapse in this aquifer and any extraction from this aquifer will have a negative impact on the river systems as this is most likely where the recharge of the aquifer will come from. These are the same rivers that are now dammed to extinction throughout the Western Cape.
- Recycling of sewerage effluent: while this is to be supported, it must be understood that this will not be acceptable to some of our religious groups. It should also be noted that our sewerage systems are in an unsafe condition, and we need some 6.6 billion Rand to upgrade and build new sewerage treatment works. Here too energy plays a huge role, as 90% of the running cost of our sewerage treatment works is the energy cost of pumping water around the various treatment sewerage works. At last check there was only 300 million on any long term budget for upgrading sewerage works. Continue reading