Diagnosis of water crises in the metropolitan area of São Paulo: policy opportunities for sustainability

Water resources sustainability is critical to urban areas that are facing increasing water crises. Understanding the interactions in a system perspective is necessary for designing policies for sustaining water systems serving concentrated urban centers. This study uses the dynamics of Cantareira Water Supply System to diagnose the recent water crisis in the Metropolitan Area of São Paulo, Brazil. We assessed the system data using generalized linear, mixed models. The results show a high seasonal variation between dry and rainy periods. The temperature increased in 2013, while the reservoir volume has been reduced since 2012, as well as the precipitation and spring inflow. The water supply is influenced by spring inflow, precipitation, evaporation and extent of withdrawals. The increase in temperature and the population growth can bring a worse water crisis in the near future. Integrated watershed management is important to improve the water sustainability in cities and need comprehensive strategies for sustainability.