Bente writes*
How do we stop a “day zero” of running out of water? Cape Town was one of the first cities facing this problem. How did it escape — and can it do it again?
Day Zero is reached when Cape Town’s dam levels fall below 13,5% (Climate Portal, 2022). During the severe drought of 2015-2018, dam levels were under 21%, and taps were on the verge of going dry (memeburn, 2018). Farmers helped by giving their water to the city. The government added restrictions to water use, increased water tariffs for heavy water users, and reconfigured its pressure management system — saving around 10% of supply (Global Resilience Institute, Bloomberg, 2019). The return of rain also helped, but these actions and results may not be easy for the next drought hitting Cape Town or another city.
So which measures should always be taken to avoid a day zero? The answer may be by trying to change the water usage habits of citizens. How did Cape Town change this successfully? They started by making things such as filling pools, water gardens, washing cars, or other non-essential uses illegal (National Geographic, 2018). Restaurants asked people to minimize toilet flushing with the slogan “if it’s yellow, let it mellow” (World Economic Forum, 2019). But maybe the most important measures were the social controls that the city implemented. This started with weekly updates of the dam levels to create awareness of water scarcity and digital boards on highways that counted down to Day Zero. In 2018, the city published a city-wide water map showing household level water usage, which helped people hold each other accountable (Bloomberg, 2019). An online community shared tips for saving water.
Do social norms work in long term? Demand is increasing again because social measures only worked when the drought was severe. When supplies returned, so did demand. It is necessary to “destroy” demand if the city wants to avoid a future day zero, by encouraging people to permanently reduce their demand for water.
Bottom Line: Cape Town implemented restrictions to avoid Day Zero once; if it wants to avoid a future day zero, then it needs to destroy demand.
* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂
I found this report on the past and present water situation in Cape Town very interesting. In a late paper, Bateson wrote about societies rising and falling because they use up all the “elbow room” that allowed them to grow in the first place. Apparently the folks in Cape Town are in the process of using up all the water-related elbow room they created when Zero Day was a real and present danger.
Bente, thank you for the fascinating read. That is astonishing that they were able to decrease demand by almost 50% within a few years. Clearly, decreasing demand is an attainable goal. I also think that the racial/socio-economic divide is something valuable to highlight in the case of Cape Town. A majority of the Black population lives in townships on the outskirts of Cape Town. To this day, they face challenges in accessing clean drinking water so Day Zero is an ongoing challenge for them. I am curious what measures, if any, the government has put in place during these campaigns to account for this divide? Did the “increased water tariffs for heavy water users” cross-subsidize the water costs or were tariffs still well below supply costs? The reality of water scarcity seems very different for different groups of inhabitants and changing social norms is difficult to do if it’s a matter of life and death. For the most part, these are just questions/thoughts that came up for me while reading your post. You don’t have to answer them, I hope that they can maybe be useful for exploring a new perspective. It’s up to you but I appreciate the insight on Cape Town’s struggle with water scarcity.