The unprecedented drought experienced by the southwestern Cape over the three years from 2015 to 2017 is commonly assumed to be the result of climate change. University of Cape Town Pro Vice-Chancellor for Climate Change, Prof Mark New, gives the scientific view. “We can’t say the drought itself is due to climate change, but the risk of droughts like this is definitely increasing because of climate change.” Based on the analysis, the risk of a drought like the recent one is believed to have increased threefold compared to a world without global warming. Put differently, without climate change, droughts like this would be one third as frequent. The expectation is that the risk will double again over the next twenty to twenty five years, making a drought like this six times as likely as in a world without climate change. “Essentially what we’re seeing is a consistent trend of a drying climate in the southwestern Cape, and because the underlying climate is drying then the chances of getting three dry years in succession like we’ve just had increases more and more, because you’re shifting the baseline of the climate towards drier and drier conditions … This is essentially the message that we’re putting across … not saying every year is going to be like the last three years but the frequency with which events like this actually occur is going to become much more regular.”

Dr Piotr Wolski, Research Associate at the University of Cape Town’s Climate System Analysis Group, compares the severity of the drought to the system’s assurance of supply. The 2015-2017 drought was a very rare, very extreme event, estimated to occur with an average return interval of once every three hundred or four hundred years. The Western Cape water supply system was designed to deliver a 98% assurance of supply, meaning that, given prevailing rainfall patterns, two out of every hundred years, or one out of every fifty, there will not be sufficient water in the system, and severe restrictions will be required to get through to the next rainy season. A system in principle designed to cope with deviations from average rainfall occurring once every fifty years will struggle to cope with much more severe drought events with a significantly lower probability, deviating so far from the average that they occur only once every three or four hundred years. “Essentially, the system had no chance to provide uninterrupted water supply to Cape Town residents and the region’s agriculture during that event … The 2015-2017 drought was a very strong, very extreme climatic event, and the severity of it by far exceeded what the water supply system could have handled … That puts whatever was happening on the authorities’ side in a slightly different perspective and somehow exonerates them from responsibility for the water crisis.” To this has to be added, though, that in reality, due to a number of operational issues (such as clearing of alien vegetation from catchment areas that was not being done as required for the proper functioning of the system, among many other issues), the water supply system was in fact running at a much lower level of assurance, likely to fail once every twenty years.

How did the Western Cape water supply system continue to supply under extreme drought conditions? “Really what it meant to deal with such a severe drought is that water use had to be restricted very harshly,” says Barry Wood, Manager of Bulk Water, City of Cape Town. While normally you wouldn’t take restrictions to more than around thirty percent, “in this case we had to go as far as forty five percent restriction on urban and sixty percent restriction on agriculture. It was very painful, particularly for agriculture as well as the urban sector, but it was the only way to get through. We mustn’t forget we’re dealing with natural systems like rainfall and surface water systems. When you move into drought you have to restrict use. You cannot build yourself out of a drought – you do need to restrict use, and that is built into the rules of the system.”

With the benefit of hindsight, Peter Flower, City of Cape Town Water and Sanitation Director during the crisis, looks back at decisions regarding the implementation of restrictions during the early phase of the drought. Despite earlier recommendations to put restrictions in place, “it was only later in the year that the [national] Department [of Water and Sanitation] promulgated a twenty percent restriction level, which was too late to save through that really hot, long summer of 2015-16 … That was really when things started … The earlier you can start restricting when you start suspecting that it’s going to be bad, you don’t have anything to lose by putting restrictions in place, even at a reasonably moderate level, but it makes sense to save it while you’ve got it. To go and put heavy restriction measures in place later on when your dams are already low, it also helps, but start saving it as early as possible. I think that’s also an important message.”

Unlike rapid-onset disasters which draw public and leadership attention and call for immediate responses, slow-onset disasters have the added challenge for decision makers of when, and on what basis, to call a crisis. "I think that when you frame issues, using information and using data, for leaders, and say, this is where we’re headed, or could be headed, it helps to focus decision making," says Craig Kesson, City of Cape Town Chief Resilience Officer. In these circumstances, calling a crisis is a function of leadership, and requires the balancing of risk and probability given the information at your disposal at the time. "The lessons are fairly plain if the crisis is immediate and you have to respond to things that are falling down around you immediately. But when you are thinking about the future, is to act on the information and data that you have and accept different perspectives. And so if you took water out of the equation and you said, well, here are the options before you – it was a very good framing device."

Peter Flower was Director of Water and Sanitation, City of Cape Town during the crisis. Here he shares the challenges experienced by his teams of officials tasked with implementing the emergency build programme. “It was a build programme that, in my view, and in many of the officials in my department’s view, was really on a road to fail … We were required to produce the engineering work to facilitate the Water Resilience Programme, and the guys worked day and night to do the work, and it was significant. Because it’s not just the simple engineering, you’ve now got to deal with land acquisition, you’ve got to deal with environmental constraints through environmental legislation, you’ve got people objecting, you know, people living on the coastline near to where these are going to be … It was a multifaceted problem to deal with that was never going to be managed within the timeframe that was envisaged. What I was trying to advise was that we certainly start going down the road of developing alternative water resources, because we needed to diversify away from being solely reliant on surface water, that was clear, but that we couldn’t use that as the means of saving Cape Town from the drought. It would have to be done in parallel, but with more focus on the demand management … So yes, we needed to ramp up the additional water that would be feeding into the system, but there was a natural limit on how much you could do, and to just set unrealistic targets because it suited a programme, and then expect those to be met, it had never been done anywhere else in the world.”

Craig Kesson, City of Cape Town Chief Resilience Officer, who led the Water Resilience Task Team during 2017, articulates the manifold constraints encountered with the emergency build programme. These included limitations on operational and procurement capacity, and dramatically escalating assessments of cost. “I think from a professional perspective where the Water Resilience Task Team changed in its approach between June and August/September of 2017 is that once we had recalibrated the costs and the operational and project realities of delivering a 500 megalitre augmentation programme, our professional assessment was that it would be almost impossible to do, and certainly within the timeframes that we were given. And that if you wanted to pursue it, even if you could find additions to the budget, the real problem was capacity. And my biggest concern was getting things through the procurement system, which would have to be reprioritised to accommodate the tremendous burdens that we would be asking of it in order to do 500 megalitres of augmentation, as well as the actual professional people to deliver such a programme.”

Aurecon water resources engineer Dr Lloyd Fisher-Jeffes dispels misconceptions around the modelling of the system and the notion of assurance of supply. “The city has roughly fifty percent of its demand also assured at a one in two hundred year event, meaning that in a severe drought of one in two hundred years you still get fifty percent of your supply … In this case we had a one in three hundred year [event], as an individual year, and the drought itself was one in six [hundred years], and we only needed to go down to a forty five percent restriction, which, to me, implies the planning, what was planned, was realised … A surface water scheme assumes the ability to restrict and take you down, and the long-term planning has incorporated that into it and assumed that you can restrict. Now, what I think was partially misunderstood was that restrictions are a key part of the surface water scheme. And that assumption of being able to restrict fifty percent might not be so palatable to everybody, but no one had really taken that in and understood that to be what it meant. And now all Capetonians know what that means, because we’ve had our almost forty five [percent], and they’re maybe not so keen on experiencing it again. So we need to maybe rethink about how much we can restrict, especially after a drought like this where everyone has become more water efficient. Can you restrict another fifty percent in the future? I would probably doubt that … I think the resilience of the system was clearly demonstrated by us not running out of water.”

“Science [has] shown us that we’re losing fifty billion litres of water every year currently, and if we don’t do something about it we will lose double that by 2045.” Louise Stafford, Director of The Nature Conservancy, sketches the impact of alien infestation in the catchment areas, and outlines the plans for remedial steps. “So to put the fifty billion litres into perspective, it’s about two months’ water supply for Cape Town alone. So if you look at the current water usage which is in the region of 609 million litres per day, we lose 22% of that as a result of alien plant infestation in our catchments … We looked at catchment restoration as an option, and we compared that with the current options on the table. How does it compare to desalination in terms of cost? We also compared it with groundwater, re-use and additional dams, and this [has] shown that we can get the same amount of water into the system at a fraction – ten percent – of the cost of a combination of the existing options.”

“What’s not necessarily understood and maybe needs to come out more is that when the system’s planned it’s planned at an aggregated level, it’s not planned at a household level,” points out Dr Lloyd Fisher-Jeffes, water resources engineer with Aurecon. “So when there’s a forty five percent restriction required, that’s not a forty five [percent] restriction for everyone based on what they’ve been using before. So if you consider that a household in, say, Bishopscourt is using 360 litres per capita per day, or more, and in Rondebosch it’s probably around 300, in town it’s also probably around 300-350, before the drought, on a per capita basis. When we require forty five percent reduction in water demand from the city, it’s not forty five percent or fifty percent of your 350, taking you to 175, because on the other hand there are a lot of people who are using only say fifty litres already … That’s a large proportion of our city. Now it’s no longer fifty percent for your 350, you actually have to reduce your demand to account for that, so it ends up being a sixty, seventy, seventy five percent reduction for those who were using water freely.”

Prof Martine Visser of the University of Cape Town’s School of Economics discusses the findings from her work with the City of Cape Town at the onset of the drought period using behavioural nudges to induce water savings by citizens. A variety of treatments was used, including the use of social comparisons, social recognition, the public good / commons idea, financial incentives, and making tariff structures more salient. “Overall consumption on average for the people who were treated in the sample was consistently one percent below that of the rest of the population, and overall the cumulative savings over a two year-period staved off Day Zero by three to four weeks in terms of the total volume of water saved. So that was really a take-home message for me, that while behavioural nudges might not seem ... substantial at the time, they can be very usefully combined with other economic instruments to supplement water savings over time.”

Priya Reddy, City of Cape Town Director of Communication during the crisis, describes the difficulty she experienced first-hand of segmenting communications markets, of targeting different messages to local and international audiences. “As much as one would like to segment a market, and say, this is the message for people in the city, it’s dire, you need to save, but for the rest of you, please come, please continue coming here, please save our jobs, please, as we coin the phrase, save like a local when you come, but don’t not come, it’s not possible in the day and age we live in where there are platforms that are globally reaching, there’s the Twitters and the Facebooks and TV ... You can’t really segment the market like that. So I remember just having that moment of thinking: it’s the message we wanted but perhaps it’s not quite the audience we wanted.”

David Green, CEO of the V&A Waterfront, gives a sense of the damage to international tourism numbers inflicted by the Day Zero messaging. Measured by the occupancies of the fifteen hotels in the Waterfront, it was a reduction of between fifteen and twenty percent. “Now that is against the background of Cape Town over the last three/four/five years following 2010, tourism numbers had grown by eight percent. So at the peak of the damage you’re close to thirty percent reduction. So this was quite damaging to a valuable part of the economy … Unfortunately the impact of the Day Zero messaging was incredibly strong internationally, and tourists felt a moral responsibility to avoid coming to Cape Town because they didn’t want to drink Capetonians’ water ... There was a point where the realisation within the tourism industry was that the bigger crisis was the economic crisis that this Day Zero messaging was going to have. So there was a conflict between the messaging the City and the Province were putting out, understandably, with a view to holding down and keeping people pressurised to reduce their water consumption, but that was playing out internationally as affirmation of the likelihood of this crisis, and this was exacerbating the potential economic damage that would be suffered.”

Prof Martine Visser of the University of Cape Town’s School of Economics worked closely with officials of the City of Cape Town to roll out the water map in 2018, “which worked on the principle of the social norm that people would be able to see their own usage compared to that of their neighbours.” It was a live map that enabled users to zoom in to individual property level, showing households that were complying (using less than 10,000 litres per month) with a light green dot, and those that were doing even better (using less than 6,000 litres per month) with a dark green dot. “Households who did not comply just got a circle without any colour in it, so it was kind of apparent if you weren’t compliant, but the focus was really on good behaviour and compliance … Certainly what it did is it resulted in a lot of public discourse around inter-household consumption, and it allowed people to look at different neighbourhoods and make comparisons, and within neighbourhoods people had quite constructive discourse around their use and how they could improve it … The first time that anything like that has been done … It’s certainly I think a tool that other cities could look at using in future.”

GreenCape water programme manager Claire Pengelly discusses the challenge of non-revenue water – water that, for a number of different reasons, is not charged for, whether for billing reasons or through leaks in the pipeline system. “Obviously to have a viable water business within a municipality – the municipality is buying water from a bulk supplier and then selling it on to the end users – so you want to make sure as a water business that you’re not losing a whole lot of your stock. But what we see is that across South Africa the non-water rate is incredibly high – it’s around 41% at the moment. So I mean think about that. 41% of the water that is supplied to a municipality is being lost or not charged for in one form or another.” Cape Town, on the other hand, has done very well on non-revenue water, from long before the crisis, and has received international awards for the work it has done on this. Indeed, it is largely through these measures that Cape Town was able to keep its water usage constant over a fifteen-year period despite an increase in population of one million. Cape Town’s unaccounted-for-water rate is around 14%. This compares to around 20% in London, for example.

One of the standout successes of the water crisis period in Cape Town was the pressure management programme undertaken by the city. Barry Wood, the City of Cape Town’s Manager of Bulk Water, describes how the existing pressure management programme, already in place when the drought hit, was ramped up aggressively during the crisis, and then rolled out across larger areas, to great effect. Initially done manually on a 2.4 metre diameter pipeline, saving around 25 million litres per day, an automated pressure management system was later rolled out across large areas of the city. Within a few months, the city was able to save around 70 million litres per day through pressure management. “So by expanding the area of pressure management in Cape Town we were able to very quickly generate fairly significant saving of water. It was a successful programme, and it’s of the largest probably even internationally … It’s relatively cost-effective to do as well, as compared to, say, augmentation, so it is value for money. And it is optimising because you are reducing your losses. And it protects your infrastructure. Other than the obvious of reducing your leaks, in the municipal and in the private household plumbing, it also does protect your infrastructure because it’s operating at lower pressures. So you do experience less normal pipe bursts, in the smaller pipelines.”

While sound in theory, water management devices turned out to be a source of contention and discontent among users, generating significant bad publicity for the city authorities, particularly as the installation was ramped up dramatically during the crisis – at one point the City was installing close to 20,000 per month. Dr Kevin Winter, senior lecturer in the Environmental and Geographical Science department of the University of Cape Town, gives a dispassionate account of the experience in Cape Town. “A water management device is important to measure water, it’s all about trying to understand what a user’s needs are, and to control those needs … So these devices were able to open, allow water through, throttle that water to some extent, and to close it off when that particular limit had been reached. That’s in theory a really excellent way to manage water and reduce the amount of wastage, particularly if there are leakages in homes.” He gives the reasons why these devices turned out to be problematic in practice.

The cornerstone of the City of Cape Town’s disaster plan was the concept of points of distribution dotted around the city where citizens would have to collect their daily ration of 25 litres per person once the reticulation to most households had been turned off. Councillor JP Smith, Mayoral Committee member for Safety and Security in the City of Cape Town, shares the thinking, the planning, and some of the detail behind this concept. Implementation was delayed so as to avoid incurring costs unnecessarily. “If we had for argument’s sake decided to go and build the water collection points, or the points of distribution, in January when we realised that this might be a likely outcome, we would have spent several hundred million rand which, as it turned out, we were able to avoid. What it did do is tell the public that we are not kidding, this is a very real scenario, it is very possible that around April you may end up without water.”

Nardo Snyman, sustainability specialist with Growthpoint Properties, relates the company’s experience with a commercial building in Cape Town where a project was undertaken to filter to potable standard the sump water that had previously been pumped out to prevent the basement from flooding and then disposed of. Initially the company was not allowed to sell this water to its tenants and take the building off the grid, but after successful lobbying and with the cooperation of the City’s legal team, the company was able to proceed. A reverse osmosis plant was installed and the tenants are now supplied with water originating on the property. The water is remineralised to a high standard, and real-time water quality monitoring is in place to ensure compliance with health and safety requirements.

Insurer Old Mutual undertook a successful waste water re-use project on its campus that is used by up to 12,000 people every working day. Khiyam Fredericks, Old Mutual National Technical Manager at the time of the crisis, describes the planning and execution of the project, the operation of the system, and the work that had to be done to ensure acceptance of the product by the users on the premises. “How to make people that are going to be using this on-site, accepting of this sort of concept of drinking waste water – or well, drinking clean water from waste sources. The entire sort of behaviour and awareness of people and our communities were quite awesome at that time. Yes, it was a scary moment we had this crisis, but everybody knew that they needed to do something, so they were very much on board with this concept … I invite the staff, any concerns they can come to us, and I take groups of people through the actual water filtration plant, expose them to the technology so that they can see this is what’s happening, show them certificates, prove to them that the water is safe by showing them the independent tests and assessments that are being done. People are quite wowed. I have ninety / ninety five percent of people that come on the tour that say they will never drink the water, leave the premises being a champion for the cause, and they can really see that it’s quite amazing things that can be done.”