Water crises in São Paulo, Brazil

                                                                   

Me visiting one area of the dry reservoirs outside Sao Paulo
end of October, 2014. Photo Daniel Meyer

This blog starts with a subject of vital importance for life: Water. 

During one of my recent working trips to the city of São Paulo (end of October) I took the chance to visit the outskirts of this large metropolitan city. I wanted to take a look, and some photos, of its water supply system - Sistema Cantareira (Cantareira system), featuring declining water levels due to a 13-month drought. Composed by a series of different reservoirs and tunnels, the system was constructed in the 60-70ths to satisfy the needs of an expanding urban population and a growing industry. It’s according to many specialists one of the most efficient and modern water supply systems in the world. 

A dock without
its boat.
Photo Daniel Meyer

The south-eastern region of Brazil is, however, experiencing its worst drought in 80 years and this is taking a hit on the Cantareira system. Rain has been very scarce during 2014. Seven months have passed without the system registering any increase in water levels. The last time the reservoirs volume increased was on April 16. On occasion, the reservoirs rose from 12% to 12.3%. With rain up to 70% below average during the last summer (rain season in the State of Sao Paulo), the water level of Cantareira system has now reached critical levels. If the precipitation anomaly repeats itself this summer (December – March) there is a great risk of a collapse in Brazils largest city.

Already in May this year the situation was alarming, with water levels dropping to 8.2%. At that time, and in order to avoid rationing, the state water utility Sabesp (joint venture between (50.26%) the state of São Paulo, (25.5%) Bovespa Bank and (24.2%) the New York Stock Exchange) - spent 80 million reais ($33.6 million) to tap so-called technical reserves (water below the level tapped through gravity). 

Sabesp pumping up the technical reserve (dead volume)
Photo Daniel Meyer

Despite this measure, in November, almost all reservoirs were showing a decrease of 0.2% per day. And at least 60% of residents of São Paulo have complained of lower flows from their taps during the past months. Schools and hospitals, and even some industries, have started to slow down their activities. Moreover, the technical reserve has been entitled by environmentalist as a ”dead volume” as it contains sediment pollution and heavy metals.

But how could it be that water reservoirs of one of the world largest cities are turning out into a dried-up bed of cracked earth? Some interlinked factors have been raised to explain the water crises:

- To much consumption and dependency on stable rain patterns

Low levels of one of the reservoirs. Photo Daniel Meyer

Its not news that São Paulo metropolitan area, with its 20 million inhabitants, major financial centres and powerful and energy consuming industries, is a very high water consumer. Consequently, it’s very dependent on the summer rains to fill up its reservoirs, as during the winter (dry season), water demand is much greater than water supply. 

- Management problem
The state government and its joint partners seems definitely to have failed in measures and preventive actions of this water crisis. The major measures taken so far is to give consumers a "bill discount" for those who reduce their water use, as well as pump up water reserves. Furthermore, 10 years ago, when permission to withdraw water Cantareira was renewed, the contract demanded the creation of alternatives. However, according to recent investigations, the company that manage Cantareira continued to withdraw the same amount of water from the system without creating new investments in other areas. Moreover, according to some studies, there are many water leakages in the city pipes, and most of the São Paulos sewage is not even treated (according to some studies 64 cubic meters of sewage is produced per second by the city, while only 33 m³ / s is treated).

- Deforestation and flying rivers

The State of São Paulo is basically formed by the Atlantic Forest and Cerrado biomes which help regulate amounts of moisture in the air. Most of its natural vegetation and forest has however been deforested since the arrival of europeans, mainly due to agriculture activities such as coffee, pastures and sugar cane. Today the landscape in the region is very fragmentised and show large deficit of forest areas (in violation to the environmental law). Another theory, launched in 2009, by the scientist Antonio Nobre from the Center for Earth System Science - CCST / INPE, warned that decades of deforestation in the far away Amazon forest could also be interfering with amounts of moisture in the air, as the Amazon forest function as a giant water pump which generates large amounts of water which circulates in the west and south of Brazil. Without these "flying rivers" Noble said, the area responsible for 70% of the GDP of South America could effectively become a desert.

Dry parts of one of the reservoirs.
Photo Daniel Meyer

Concluding, taken into consideration that São Paulo is one of the most populous (20 million) metropolitan areas in the world, and is the engine of Brazil's economy with a water depent industry (agriculture, food and fibre, car and truck manufactures etc.), a complete water rationing here would probably have unimaginable consequences. Such situation has however not yet appeared and water is still available in and around the city. But with the reservoirs (water levels currently at 10%) showing a decrease of 0.2% per day, and with 60 % of residents having experienced at least one outage in the last months, you don't need rocket science to understand what might be looming in the horizon. The passive stance, however, taken by authorities until now (bill discount for less consumption and pumping up water reserves) shows that politicians are still betting that this 13-month drought is part of a shorter cyclic phenomenon, putting their hope on the upcoming summer rains. Despite, what we need here are much more comprehensive and innovative actions, stretching far away from the boarders of the Cantareira system and old water management paradigms.

Finally, driving back from the Cantareira system, I found out that my rented car was full of dirt from the muddy roads along the reservoirs. At the car rental office the manager told me it was ok as they were only using wet cloths to clean the cares due to water consumption restriction imposed by the company. At least a glimpse of hope I guess. 

Check out the Cantareira System water levels by accessing Sabesp homepage:<http://site.sabesp.com.br/site/Default.aspx>