Metropolitan São Paulo, Brazil is home to about 20 million people. It’s also almost out of water, according to officials there. The city has been tapping into reserve supplies to meet demand, and some water experts have warned that an ongoing drought could leave reservoirs completely dry.

Newsha Ajami recently visited Brazil at the invitation of São Paulo state officials, who were referred to her by the United States embassy and the U.S. Department of the Interior. As part of an “information exchange,” Ajami met with representatives of the state governor’s advisor on water issues, federal and state water agencies, Brazilian universities, the U.S. embassy and other organizations.

Ajami, the director of urban water policy at Water in the West, a joint program of Woods and the Bill Lane Center for the American West, discussed her trip, the São Paulo’s challenges, possible solutions and a few surprises along the way.

How bad is São Paulo’s water problem, and what led to it?

They are in a serious drought. The city’s main reservoir is below the dead zone (the minimum level at which a reservoir is designed to be drawn down from). Metropolitan São Paulo loses about 40 percent of all water to leakage and system inefficiencies. They told us that they have tapped into their third and last remaining water reserve, which guaranties only 30 days of water supply. The city’s problem arises mostly from mismanagement of existing water resources, which has been exacerbated by a drought. They Tietê River runs through the city, but its water is heavily polluted due to direct discharge of untreated/raw sewage from upstream. This water could be a great source of water for the city if treated and reused. 

                                               (The City of São Paulo. Photo credit: Jonathan Olsson)

How are officials in São Paulo dealing with the water problem?

They offer their customers up to 30 percent “bonuses” for conserving water. However, they are not very open to the concept of mandatory rationing since in São Paulo it is interpreted as turning off the water supply. This could be costly to the water agencies and also lead to contamination so the officials and water mangers prefer to avoid that. We also discussed possibilities of implementing a different pricing structure that would encourage conservation while sending price signals to water wasters. But, because the multi-unit buildings only have one water meter, such pricing structures are perceived as not being fair since the water waster would not be fined directly. Solutions such as tapping into groundwater and building a water transfer/conveyance system to bring water from Rio are on the table. There were also discussions on expanding the water supply system by building new dams. It is hard to say how in the short-term they were going to address their water availability problems.  

What did you discuss during your presentations and conversations with officials there?

I talked about long-term problems in California, such as climate change impacting snowpack and water reserves, population growth’s impact on demand, environmental and ecosystem degradation, and, on top of that, the drought, which is exacerbating these issues. I also talked about the complex and fragmented water governance structure. In California, we have 15 federal and state agencies that touch water management somehow. On top of that, you have all the regional, local and tribal agencies that deal with water. I discussed changing our mentality towards managing our water resources and creating a portfolio of solutions to manage water demand and augment supply.

The water problems in the state of São Paulo are slightly more complex compared to California. Quality of drinking water is still a major concern to everyone. The majority of residents do not drink the tap water. Consequently, most of our discussions were focused on challenges and opportunity related to both quality and quantity of water.

What would you propose as possible solutions?

We discussed the solutions California has on the table to manage current drought and long-term water challenges, including everything from demand management, leak prevention and efficiency measures to reuse, changing price structures and exploring more innovative financing options. The water resources management in California is going through a paradigm shift. While there is much work to be done, there is a recognition that we have to redo and rethink our water supply solutions.  I mentioned that in California we are now talking about a portfolio of solutions. Cities like San Francisco are tackling their water challenges on all fronts, while managing demand. They’re also rethinking their future supply portfolio and possible regulatory reforms that are required to expedite implementation of some of the solutions. I also focused on what we can do to augment supply through approaches such as stormwater capture and reuse. Finally, we discussed financing mechanisms and cross-sector management – coordinating land use and water management and planning and the water/energy nexus.

The city of São Paulo could do a lot by focusing more on management of the resources it already has. For example, there is an opportunity to save water by fixing leaks and inefficiencies in the water system and examining recycling and reuse of water of the Tietê River. Then you’re fixing two problems, treating public health challenges related to pollution and sewage in the river and providing additional clean water for use. The city of Limeria, which is 100 miles from the city of São Paulo, has already reduced it leakage to 16 percent, which is less than half of the statewide average.  

Was there anything about the city’s water system that seemed unusual or surprising?

According to officials, the city of São Paulo has a system that collects stormwater and sewage separately. Unfortunately, most of the collected stormwater is discharged to the Tietê River, which is already polluted by sewage. Having a separate sewage system could cut down on the amount of resources you need to put into treatment of wastewater for use or before it is released to the environment. Another very interesting fact about the city of São Paulo is that every house has to store a 24-hour supply of water onsite. Also double flush toilets and water meters are common in the city.  

What does the future hold for this collaboration between Stanford and São Paulo?

It’s always a great opportunity to have international partners. It can facilitate knowledge and information exchange and partnerships that could potentially lead to interesting research projects and on-the-ground solutions. In São Paulo, we discussed hosting some of our Brazilian counterparts in California and the possibility of arranging a roundtable or a meeting at Stanford in partnership with the San Francisco Public Utilities Commission (SFPUC) to further discuss solutions to our water challenges.

The Stanford Woods Institute is finding practical ways to meet growing demand for freshwater, both in developed and developing nations, including the use of recycled water and water resources. Learn more about Woods-sponsored freshwater research.