The eThekwini Municipality's Water and Sanitation (EWS) Unit's number one priority is to deliver water to people efficiently, economically, reliably and equitably - and, in so doing, to help conserve South Africa's precious water resources.
Head of EWS, Neil Macleod, said the most important thing to remember on Earth Day was that sensible water management is not just about saving money, but about caring for the environment. According to the United Nations, South Africa and 14 other African countries are already faced with water scarcity (when less than 1 000 m3 of water is available per person per year). At least four more - Kenya, Rwanda, Somaliaand Morocco - are expected to face water scarcity within the next 10 years.
Macleod said that because, according to the Department of Water Affairs (DWA), domestic usage is expected to increase the most, it is crucial for EWS to not only ensure that the city has sufficient water for its future, but that usage is carefully managed. "With the democratisation of South Africa, the operational area of eThekwini Municipality increased 10 fold, providing massive engineering challenges when it came to delivering safe water and sanitation as well as conserving water wherever possible. With demand rising and leaks escalating due to the old infrastructure, we realised that we needed to intervene to prevent demand exceeding supply," he said.
The municipality currently purchases 860 million litres of water daily but only sells 573 million to consumers. Sixty per cent of the water demand is domestic usage and the balance is used by the Industrial, Commercial and Institutional (ICI) sectors. By implementing a number of interventions, bulk water purchased over the next three years is projected to be held steady in spite of a 2% annual growth in actual consumption.
Chief among these interventions is eThekwini's R600-million "Sustainable Water and Sanitation Development Programme for Indigent Communities" project. Over the next three years, it is expected to help the municipality provide 800 000 people living in informal settlements with safe drinking water and sanitation. The project hinges on three key infrastructure development pillars, pipe replacement, installation of ablution blocks in informal settlements and the monitoring, management and reduction of non-revenue water. R100-million will go towards the pipereplacement programme, R400-million to the flagship sanitation project and R100-million to the reduction of non-revenue water. Approximately one third of this programme will be funded through a grant from the Dutch Government.
Simon Scruton, manager of the Non-Revenue water branch said that EWS adopted a 10 year water loss target in 2007. Substantial reductions in leaks and theft are expected to help achieve a medium term goal of reducing non-revenue water in the municipal area from the current level of 33% to 25%. According to World Bank publications, this would place the eThekwini Municipality in the top 35% of water systems in the developed world and in the top 15% in the developing world.
According to Macleod, pressure management has proved to be the most effective intervention. The municipality began commissioning additional pressure-reducing valves (PRVs) throughout the city in 2008 to increase the lifespan of water mains, decrease the likelihood of burst pipes and, ultimately, stem water loss.
He said the average drop in pressure is from 580 kpa to 420 kpa which few consumers notice. "The major difference will instead be a reduction in overall water loss by 105-million litres daily. Every R1m invested on pressure management translates into an R3-million saving on water loss."
Since the implementation of the PRV in the Durban CBD, in August 2009, the City has saved over 35 000 000 litres of water every day. At a cost or R100 000, the CBD PRV was recently augmented with a state of the art remote node pressure control device. Scruton said that this has been a tremendous success and this is saving the city a further R750 000 per annum.
The volume of water currently being purchased from Umgeni Water has fallen by 73 million litres a day which has, in turn, resulted in an energy cost savings of R5million per annum as less water needs to be purified and pumped.
Going forward, Macleod said EWS plans to install 800 new PRVs plus 200 new pressure control devices. "We are also inspecting the entire reticulation system to detect leaks. Inspecting and picking up small leaks early prevents major bursts which can result in the loss of several 100 thousand litres of water."
He said that a well managed supply of safe water to residents could also be optimised through encouraging re-use of waste water. "For example, we have water reclamation works that converts 35 000 kl of domestic sewage into second class water every day. This is almost to drinking water standards. It is then sold to business for use in industrial processes and the companies' benefits from utilising cheaper water. From our perspective, we can then send our precious potable water to consumers that need it most."
Macleod appealed to all consumers to help EWS optimise the management of water losses for their benefit as every kilolitre saved translates into a saving in kilowatts. "We need to optimise and reduce our impact on the planet wherever we can. We are working hard to minimise water losses but need the public's support.