20 lessons from São Paulo’s Day Zero

I say Day Zero, you say? Cape Town. But Cape Town is not alone.

For South Africans (like me), Day Zero is that day that Cape Town runs out of water. Recently, Capetonians faced each day with 50 liters of water, a crisis ignited by a drought like almost never before. Day Zero would have been triggered when dam levels reached 13.5% and city management turned the taps off. Then, people would have had to queue for a precious 25 liters of water, from around 200 sites across the peninsula. The logistics were  mind-boggling. What about people who couldn’t get there, or carry their water?  How would you have kept the water safe from theft? How would this have affected business, and sanitation? Luckily, we never found out. It started to rain. As I write this, dams are filling up again, indefinitely postponing Day Zero.

However, elsewhere on the planet, Day Zero has been a much bigger reality. Extreme drought has brought cities other than Cape Town to their knees.  In 2015, São Paulo had less than 20 days of water left. Now, São Paulo is not a city that you should take lightly. It’s one of the 10 largest metropolitan areas  on the planet. Almost 22 million people call it home.

Check out this footage from TIME to see what life was like in São Paulo during the water crisis:

It was a close call, but the city survived. Yet, in the words of Jerson Kelman, CEO of São Paulo’s water and sewage supplier, Companhia de Saneamento Básico do Estado de São Paulo (SABESP), “we should strive for the best but be prepared for the worst.” As a result, the city is working hard to become stronger in the face of future droughts.

We should sit up and listen too. According to the Environmental Outlook to 2050  published by the OECD, 6.4 billion people could live in cities by 2050, demanding a whopping 55% more water. At the same time, water will become more scarce, and the playing field more uncertain. Those responsible for keeping the taps running will face many challenges. The people that depend on them must share this responsibility. As such, the lessons learned from São Paulo is valuable to all of us in cities already familiar with drought, or facing a future without enough water.

São Paulo is one of the 10 largest metropolitan areas in the world, and called home by almost 22 million people (source: Pixabay, Joel Santana)

This then, is how São Paulo stared Day Zero in the face, and survived to tell their tale.

A water  crisis like never before

São Paulo is the industrial centre of Latin America. The capital of São Paulo state, the city is located in south-eastern Brazil, 350 km southwest of Rio de Janeiro. It sits in a shallow basin surrounded by valleys blanketed with vast industrial suburbs. Preferred residential areas are on the high terrain. Working class residences and commercial properties are on the lower land along the banks of the Tietê, Pinheiros, and Tamanduateí rivers. The population of São Paulo’s urban area is a staggering 21 730 000. Since as recent as 2015, 2015, 664 000 more moved in.

Since we are talking about drought, it’s surprising that 12-16% of the planet’s freshwater is in Brazil. However, most is in the Amazon River and northern rain forests, beyond the reach of São Paulo. Instead, six separate dam systems supply water to this thirsty city. The largest is the Cantareira, supplying nearly 10 million people.

São Paulo Metropolitan water supply system (supplied by the World Bank)

For about 84 years, roughly 40 million liters per second (l/s) of water has been flowing into this system each year. The worst year on record was 1953, when this dwindled to 20 million l/s. Then came 2014-2015,  when this trickled to 10 million l/s. “What we had in 2014 was only half of the worst we had had before in almost a century,” says Jerson. “We were not prepared.” Suddenly, the prospect of a Day Zero loomed for São Paulo.

When drought comes, use less water

When water became scarce, SABESP started where most water management authorities do: they got people to use less water. In February 2014, SABESP  started awarding users who dropped their water use enough. The program aimed to reduce water use by 20% in comparison to the previous year. In case of success, the customer would get a 30% bonus.

⇒ Want to know how the people that manage the water in cities reduce the amount of water used? It’s called water demand management. Read all about it here.

“Demand management played a very important role in drought management in São Paulo, and the tariff bonus program encouraged the population to change their habits, adopting actions that reduced the consumption of water,” says Thadeu Abicalil, Senior Water and Sanitation Specialist at the World Bank.

In November 2014, SABESP announced that the program awarded bonuses to 53% of its customers. Another 23% used less water, but not enough to qualify for the discount. Despite extensive advertising campaigns calling for responsible water use because of the notorious drought, 24% of people used more water.

SABESP then introduced a contingency fee. They charged people who used  up to 20% more than the desired amount (which is 20% less than the previous year) 40% of the water tariff. People who used more than 20% had to pay 100% of the water tariff. “The contingency tariff was applied even for clients with a firm demand contract, mostly industry and commerce,” says Thadeu.

The daily water use per person dropped from 155 liters/person/day in February 2014 to 118 in March 2015. By July 2015, 83% of people in the Região Metropolitana São Paulo or, the São Paulo metropolitan area dropped water use, and 73% received the bonus.

SABESP also replaced old pipes, altered water pressure and provided guidance on the use of water meters. This led to an estimated 23% drop in water use, amounting to 330 000 000 m³. The discount incentive scheme achieved a further 19% drop in domestic use (330 000 000 m³ per year).

A megacity survives Day Zero

Still, as water levels dropped, panic rose. Agriculture and industries buckled, threatening a struggling economy. Mosquitoes bred in the canisters that people used to hoard water, leading to an outbreak of dengue fever. Eventually, the Cantareira system drained out, leaving the city on the brink of running empty. “I don’t know what would have happened if we lost control of the water supply for 22 million people,” says Jerson. When he joined SABESP in January 2015, they had 5% of their water stock left. It was enough water for 40 days. “In that situation, really, tension was high.”

“I don’t know what would have happened if we lost control of the water supply for 22 million people”

A combination of initiatives resulted in São Paulo’s near-miraculous change of fate.

Authorities urgently diverted water from systems that still had enough left. Pipe systems  led water from the Billings reservoir, the Rio Pequeno, and the Rio Grande to the Taiacupeba water treatment station. Within a couple of months, they expanded the treatment capacity of another, the Guarapiranga system, from 14 to 16 million l/s.

Hydraulic scheme of the Cantareira water supply system (supplied by the World Bank)

They launched intense and comprehensive programs to cut water losses.

All of this cost money. SABESP paid for most of it, and the Federal Government and the International Bank for Reconstruction and Development (IBRD) stepped in with loans.

Then, it started to rain. Ironically, it started to rain so much in February 2015 that floods crippled many areas of the city.  However, the main reservoir 60 kms away remained dry. Still, at the end of the rainy season in March 2015, storage capacity was at 15%. By February 2016, water levels at the main reservoir have more than doubled.

Building a stronger city for the future

Many measures adopted during and after the crisis increased the water reliability of the metro area, says Abicalil. “The São Paulo metropolitan area is now a more resilient city for droughts.”

São Paulo is working towards becoming a water secure city (source: Freeimages.com, A Schaeffer)

Three large projects will add a further 13 million l/s drinking water  to the metropolitan region. The Sao Lourenco public-private partnership (already underway when the crisis hit) will deliver water to the western metropolitan region. The almost R2 billion Jaguari-Atibainha project will connect the Paraiba do Sul basin to the Piracicaba, home of the Cantareira system. The third project will divert water from the Itapanhau River, which flows into the Atlantic.

Still, SABESP paid a high price for their success. In addition to the payment for these large infrastructure projects, the company’s financial stability took a hit. Because they had less water to ‘sell’ they made less money. Net profit fell by almost two thirds from 2014 to 2015. SABESP increased water and sewerage tariffs with 15.2% to try and recover some funds.

Answers and questions

Going forward,  tough questions remain regarding the payment for bulk water supply. Should they implement water rights and bulk water charges? Must users upstream compensate water users located downstream? Should city residents compensate farmers?

Thadeu points out that although São Paulo is more resilient to drought, the city is still vulnerable to extreme climate. Floods in the summer season is one example.  The quality of water in rivers and reservoirs is another.

For São Paulo to become really water secure they must consider all of these factors, says Abicalil. A future where they are strong enough to survive and thrive in a world with less water, they have to look far beyond the impact of drought, and how to supply water to thirsty cities.

20 lessons from São Paulo 

(provided by Thadeu and his colleagues at the World Bank, Water Resources Specialist Carmen Molejon Quintana and Professor Francisco da Assis Souza from the Federal University of Ceará)

  1. Action across many arenas is necessary to manage drought: Public opinion, political, legal and technical points of view count. People in these arenas must work together towards the same goal.
  2. Rules for allocating and rationing water should be decided on before the drought, together with the parties involved.
  3. The rules for public participation should be set before the drought hits: To do this during a crisis is not sustainable.
  4. To manage a drought, you need various experts: Water systems are complex, and legitimate, expert knowledge must support decisions.
  5. Water systems are complex and should be analysed as a whole: Role-players must recognise that competing uses and benefits are involved.
  6. Agile and continuous decision-making is necessary to manage drought: Response time to change must be quick!
  7. Technical expertise is essential: The technical quality of the organizations that manage the system is a decisive factor.
  8. Small changes to the system can have big impacts: Something as small as adjusting how the water flows, or the pressure in the pipes, can lead to big benefits.
  9. The people who steer the city through drought should look at the supply and demand of water, as well as how to manage conflict.  
  10. The prosecution process for those that break the rules should take place from one place: A strategy for continuous and centralized monitoring by those in power, such as the Public Prosecutor, would be good.
  11. Drought must be monitored: Authorities must identify the start and seriousness of drought. Early warnings can go a long way towards improving the impacts of droughts.
  12. A drought management plan must be in place before the drought starts: This will lead to the drought having a smaller impact once it hits.
  13. Different water management institutions must coordinated and integrate: Physical, political, institutional and social spheres should coordinate actions. Each sphere should have a clearly defined responsibility before the drought.
  14. Acceptable risk must be defined: Usually, the systems that supply our water are designed to guarantee a certain amount of water, allowing for a more-or-less 10% risk of failure to do so. To decrease the risk will be cost more, but  must be done when the system supplies water to people.
  15. Political disputes must be considered in the water management process:  For São Paulo, the SIGERH (sistema integrado de gestão de recursos hídricos) creates the space for mediation. The water law provides support.
  16. A communication plan is very important: Management must practice open and clear communication. If not, people or organisations can use noise and half-truths to gain recognition and social standing.
  17. Drought planning must include financial planning: During the crisis, the amount of water sold reduces significantly. This results in a drop in income for organisations that deliver integral services such as sanitation.
  18. Define the role of the water grant: Does it authorize water use, or define broader public policies?
  19. Consumption patterns and beliefs are forever changed: The length of water shortage impacts people’s water use habits. There is no return to pre-drought conditions. This is a positive result. Authorities should tackle any temptations to return to pre-drought levels of water use head on.
  20. A drought governance system is key: Drought management must take place in different arenas (technical, political, public opinion, legal). Technical experts are necessary for such a complex situation.

Comments 3

  1. Very interesting read. As mentioned, Capetonians are expected to consume less than 50 liters per day. Was there ever a similar target/limit imposed on Sao Paulo? The 118 liters / day achieved in 2015 is high in comparison.

    I am fascinated by the success achieved by their incentive-approach, in contrast to the punitive measures used locally (which generated extremely negative sentiment) – mostly as it would seem to not have affected the percentage of transgressors in each city.

    1. Post

      Hi Lowis, great question, thanks!

      You’re right, the amount of water used per person in São Paulo is very high in comparison to what Capetonians are using, which also shows the spectacular feat that has been achieved in Cape Town. Still, it is indeed interesting to note that there are many ways to skin the proverbial cat. The hope is that we can find the best way forward from learning from each other.

      I could not find the amount of water used per person in São Paulo during their water crisis, but have sent the question off to the people that I chatted to for this interview. I’ll let you know when I hear back from them.

    2. Post

      Hi Lowis, I just heard back from Thadeu. Their daily water use was, amazingly, not impacted as much as for residents in Cape Town.

      This is what he says: ” During the water crisis of 2014-2015, the average per capita consumption in the MRSP was reduced 24% from 155 l/c/day to 118 l/c/d. This was a result of a demand management with economic incentives (bonuses and penalties, with 82% adherence rate). This reduction in consumption represented 6.2 m3/s.

      In addition, there were other actions on supply side that had important impact: new infrastructure (pipelines and elevation stations) to transfer waters from more resilient reservoirs to the area supplied by the Cantareira system represented another 6.3 m3/s; intensified and more stringent pressure management, representing 7.3 m3/s in water savings; use of technical reserves (dead storage volumes) secured additional water stored to the system.

      Other actions were also implemented, but the above represented the trunk of water savings (demand and pressure management) and additional supply (new water transfers between systems and use of dead storage volume).

      There was no rationing, however some few areas faced water shortages during pressure reduction, affecting about 100,000 inhabitants (out of over 21 million) – static residential water tanks were distributed to low income households.

      Altogether these actions avoided systemic rationing, social and economic impacts.

      For comparison, the Federal District (3.6 million inhabitants) faced a severe water shortage in 2017-2018. Several measures followed SABESP’s approach. However, rationing was implemented (6 days with water, 1 day without), alternating water sector zones. As a result, per capita water consumption was reduced in 16% from 153 l/c/d in 2016 to 127 l/c/d in 2017.”

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