Water Resour Manage (2011) 25:3371–3386 DOI 10.1007/s11269-011-9860-8 PCJ River Basins’ Water Availability Caused by Water Diversion Scenarios to Supply Metropolitan Areas of São Paulo Alba María Guadalupe Orellana González · Rodrigo Máximo Sánchez-Román · Marcos Vinicius Folegatti · Cornélio Alberto Zolin Received: 9 May 2010 / Accepted: 3 June 2011 / Published online: 30 June 2011 © Springer Science+Business Media B.V. 2011 Abstract A dynamic systems simulation model of water resources was developed as a tool to help analyze alternatives to water resources management for the Piracicaba, Capivari and Jundiaí River Water Basins (RB-PCJ), and used to run six 50-year simulations from 2004 to 2054. The model estimates water supply and demand, as well as contamination load by several consumers. Six runs were performed using a constant mean precipitation value, changing water supply and demand and different volumes diverted from RB-PCJ to RB-Alto Tietê. For the Business as Usual sce- nario, the Sustainability Index went from 0.44 in 2004 to 0.20 by 2054. The Water A.M.G. Orellana Gonzalez had a FAPESP’s PhD scholarship and it is required by the financial institution (FAPESP) to be recognized as a FAPESP fellow. A. M. G. Orellana González Commission on Science and Technology for Development, San Salvador, Republic of El Salvador e-mail: amorellana@hotmail.com R. M. Sánchez-Román Rural Engineering Department, São Paulo State University (UNESP), São Paulo (SP), Brazil e-mail: rmsroman@fca.unesp.br R. M. Sánchez-Román (B ) Faculdade de Ciências Agronômicas (FCA-UNESP), Depto. de Engenharia Rural, Universidade Estadual Paulista“Júlio de Mésquita Filho”, Rua José Barbosa de Barros 1780, Botucatu, SP 18610-307, Brasil e-mail: rmsroman@fca.unesp.br, rmsanchezr@gmail.com M. V. Folegatti Department of Biossystems Engineering (LEB), Universidade de São Paulo, Campus “Luiz de Queiroz” (ESALQ/USP), São Paulo (SP), Brazil e-mail: mvfolega@esalq.usp.br C. A. Zolin Water Resources Management, Agrosilvopastoral, Brazilian Agricultural Research Corporation (EMBRAPA), Sinop MT, Brazil e-mail: cornelio.zolin@embrapa.br