Sao Paolo: The Psychology of Drought

Circle of Blue:

Sao Paulo is a paradox of water scarcity and abundance. Brazil’s largest city, located in a region that averages 25 more inches of rain each year than Seattle, is gripped by the worst drought in 80 years. Since the drought began last year, Sao Paulo has struggled to provide water to its 20 million residents.

The severity of the drought is apparent in Sao Paulo’s reservoir levels. Collectively, the city’s six primary reservoir systems are 27.1 percent full, compared to 40 percent full at this time last year—a difference that amounts to 274 billion liters, according to data compiled by the Folha de Sao Paulo newspaper.

Water levels in the Cantareira reservoir system, the city’s most important water storage facility is at 20 percent of capacity as the region enters its annual dry season. Cantareira served nearly half of the city’s population before the drought, but now supplies water to 5 million people as water managers turn to smaller reservoirs to relieve pressure on the system.

The Alto Tiete reservoir system, less than half the size of Cantareira, currently is at 22.4 percent of its capacity, and supplies 4.5 million people.

The city’s drained reservoirs, though, represent only a portion of the challenge facing Sao Paulo’s water managers. Another is how residents view the drought. Though reservoir water levels are disturbingly low, Sao Paulo still lacks the visual evidence of a drought as seen in places like California, Australia, and Mexico. That’s because a lot of the city is still very green and heavy rains still occur.

“They are in a drought, but the meaning of a drought is really different depending on where you are,” Newsha Ajami, director of urban water policy for Stanford University’s Water in the West program, told Circle of Blue. Ajami was invited to Sao Paulo in December 2014 to discuss water issues with state officials. Ajami added that the city flooded while she was there. “If you live in an area where drains are overflowing every time it rains, you’re not going to say it is a drought. Perception definitely matters.”

Situated on a plateau 700 meters above the sea, the city is at the headwaters of the Alto Tiete river basin and averages about 1,600 millimeters (63 inches) of rain each year—25 inches more than Seattle. Reservoirs like Guarapiranga, Rio Grande, and Billings hold large amounts of water, but they are either too small or too polluted to bolster Sao Paulo’s water security. In addition, the city is still flooding during the rainy season. Floods made headlines earlier this month, as well as in November, December, and February.

“We are definitely seeing that it has been raining less, but there have been some dramatic events,” Pedro Jacobi, a professor of education and environmental science at the University of Sao Paulo who studies water governance, told Circle of Blue . “We have a situation where the reservoirs are empty, but if it rains in the city, it has so much asphalt that if you have 50 to 60 millimeters [of rain] you are under water in many parts.”

The result is a landscape that belies the severity of the water crisis and a skewed perception that complicates voluntary conservation efforts—Sao Paulo’s primary tool for ensuring adequate water supplies in the short-term.Further clouding the public’s view of the drought is the government’s response, which has been characterized by disorder, distrust, and a general lack of urgency. For example, residents began complaining of dropping water pressure in their homes as early as May 2014, but officials did not admit to water rationing until March 2015. Instead, the government persistently held that rain would refill the reservoirs, negating the need for more drastic measures.

The Conversation:

The climatic factors influencing the drought in California and in Sao Paulo are likely interconnected. Cycles in the Pacific sea surface temperature that occur on decadal timescales are coupled to changes in atmospheric circulation that affect weather patterns worldwide. In some regions, atmospheric conditions are such that they block the passage of cold fronts that cause the storms to bring precipitation, changing the path of these rain events.

As long as these blocking conditions persist, there will be regions undergoing dry conditions, whereas others will be extremely wet. The North Pacific has been entering a phase that will likely increase the probability of these blocking mechanisms that favor dry conditions in California and other regions of the planet, including Sao Paulo.

Of course, similar oceanic and atmospheric conditions have occurred in the past and will continue to occur in the future. The problem that we should confront without hesitation is: how can global warming aggravate these extreme conditions, particularly in locations with high rates of urban growth such as Sao Paulo? How fast should governments act and how much should be invested to mitigate these unprecedented conditions?

In the Sao Paulo metropolitan region, the main water supply system, which provides water for about 8.8 million inhabitants, reached critical levels in early 2015. It had only 5% storage of its 1.3 billion cubic meter capacity on January 2015 and 15% at the end of the rainy season in March 2015. An impending ration mandate could leave residents without access to water for a few days a week.

The main water utility has already reduced pressure in the pipes to force conservation, a strategy that has cut off running water to millions of customers for hours and even days, depending on where one lives. Unlike California, isolated rain showers have occurred in Sao Paulo, and the desperate population, particularly in poor districts, has stored the rainwater in open containers and buckets to save it for the days of water shortage. Other citizens are drilling through their basement floors to extract the precious water leaving open wells.

As a consequence, the entire state of Sao Paulo, with a population of 40 million inhabitants, is undergoing a deadly dengue fever outbreak. In the SPMA, where the situation is really dramatic because of the limited access to water, the government created many improvised ambulatories throughout the city to attend the population with symptoms of the disease. Officials go door-to-door searching for infectious mosquito larvae and educating the population about the disease. However, all these measures have proven to be inefficient to control the dengue larvae proliferation.

What the future will bring for the growing population of the SPMA remains unknown. In the short term, it is possible the blocking conditions that have prevented storms from coming through will become less persistent in the next summer and increase the probability of extreme precipitation in the region. However, the temporary relief will not solve the imminent water crisis in Sao Paulo, nor in California, in the years to come.

Populations and governments in the world need to raise awareness about limited freshwater resources so the present sets the right stage for a sustainable future. No matter where we live or the rate of economic growth of a given nation, populations are, and will always be, vulnerable to water scarcity.

Resilience depends on numerous factors, but how populations will cope with disasters of various magnitudes is largely dictated by political actions, socioeconomic development and education.