AVERTING DAY ZERO
Climate change and declining water supplies mean that all South Africans, not just Capetonians, should be preparing for a water-scarce future
They’re calling it Day Zero — the day when Cape Town’s demand for water will exceed its supply. It has been pencilled in for March 2018, but the date depends partly on whether the heavy winter rains will still come.
Though the northern parts of SA have had good rains, and dams there are more than 80% full, permanent water scarcity isn’t something that will affect just Cape Town. SA’S National Water Resource Strategy foresees the country as a whole facing a water supply-demand gap of 17% by 2030 under current efficiency levels.
Unfortunately, just building more dams — assuming they could be financed and developed fast enough — won’t address the underlying issues.
The problem is that while population and economic growth will drive demand for water, supply is set to decline given a continuation of poor usage habits, water losses and ecological degradation such as the destruction of wetlands. In addition, climate change means that SA can expect lower rainfall and higher temperatures.
“Climate change is hitting us hard, and new weather patterns are diverting the Antarctic’s cold fronts south of our shoreline before they hit land,” Western Cape premier Helen Zille said in a recent opinion piece. “We [expect] that this could be a sustained trend, though no-one can tell us for sure.”
Day Zero is a moving date that will also depend partly on water usage. Capetonians have progressively reduced their water consumption, but are still consuming 26% more than the city’s new stretch target of 500Ml/day. This target has been worked out to ensure that the city builds up its reserves to carry it through to next winter.
So far this winter Cape Town has received 30% less rain than needed, and heavy rains are not forecast for the remainder of the season. As a result, the province’s dams are only 28% full, compared with 55% this time last year. The city fears that its dam system could fail in 2018.
“Failure of the water-supply system will precipitate the collapse of sanitation and other municipal services, with dire human health and socioeconomic implications,” the city’s director of water, Peter Flower, warned in a presentation to business in May.
There are 4m people who are dependent on the city’s bulk-water supply system, while roughly a third of business activity in the province is highly exposed to the risk of water shortages. The city’s brand as a top international tourist destination could also be negatively affected should the taps run dry.
Farmers and firms are being urged to brace for intermittent water shortages from next year and possibly higher water tariffs, but the main message from the province is that this is more than just a short-term crisis.
“We need to embrace the fact that water scarcity is the new normal, and all our future planning must accept that we are living in a drought-stricken area,” said executive mayor Patricia De Lille in a recent speech to the city council.
This doesn’t mean the economy need be negatively affected, she added, but it does mean the city has to embrace water reuse and desalination, improve design and innovation with regard to water use and reuse, and educate the public about the cost of producing potable water.
Many of the country’s biggest corporates have already taken bold strides to reduce their water usage. SA Breweries, for instance, managed to cut its water bill for irrigating barley by almost half in the Northern Cape town of Douglas using precision irrigation — water-scheduling software that calculates the exact amount of water needed to produce optimum crop yields in different soil types. About 100 smallscale and 180 commercial barley farmers are benefiting from the tool.
To help farmers across the Western Cape achieve higher yields on fruit and grapes with less water, the provincial department of agriculture has founded Fruitlook, an open-access, online platform that monitors the main farming areas, combining satellite imagery with details about weather. The system provides information related to crop growth, water use and mineral content on a field-by-field basis. Among other things, this allows farmers to identify which fields produce the most growth with the least amount of water, helping them to improve their irrigation practices.
Fruitlook supports more than 270 users. More than half the respondents to a recent questionnaire said their water-use efficiency had increased by 10%-30% as a result of the system.
The city itself has reduced water losses from 25% in 2009 to 15% this year by fixing leaks and reducing water pressure, among other things.
In May, the council approved the creation of a water resilience task team under the city’s first-ever chief resilience officer to lead the city’s new, urgent approach to water. Its first major act was to put out a call for information about new technologies that can enable the sustainable extraction of water from aquifers, desalination and water reuse. More than 100 entrepreneurs have responded.
The beauty of the process is that by inviting the private sector to solve the problem, the city now has a very clear idea of what can be achieved in the short term.
Using emergency procurement
What it means: Cape Town could run short of water by March 2018, but it is mobilising new technologies to prevent this