This study aimed to verify if there is a relation between the water quality of Guarapiranga System (reservoir), as it is supplied to the inhabitants, and the climate in the São Paulo Metropolitan Area (RMSP). Meteorological data obtained from the IAG/USP has been analyzed, as well as the results of laboratory analysis of reservoir water, provided by the basic sanitation company of the State of São Paulo (Sabesp). According to the results, cyanobacteria density is positively associated to periods of rainfall and high temperatures (October to March). Data analysis of climate parameters between 1970 and 2012 indicated that the ideal climate conditions for cyanobacteria proliferation are increasing. Therefore, frequency and intensity of cyanobacteria blooms in the Guarapiranga reservoir may increase if climate trend continues.
Cyanobacteria; Water supply; Weather variability; Climate change
