Agradeço primeiramente a DEUS por ter me dado forças e a persistência suficiente para vencer mais essa etapa da minha vida. Agradeço à minha querida família, mamãe, papai e meus maninhos pelo amor e pela paciência que sempre tiveram comigo em todos os momentos. À minha orientadora, Profa. Monica Ferreira do Amaral Porto, com quem aprendi muito, pela atenção e pela paciência dos últimos dias, meu agradecimento especial. Ao Prof. Rubem La Laina Porto pela confiança e oportunidade de ingressar no mundo dos recursos hídricos. Ao Prof. José Rodolfo Scarati Martins pelos conselhos e incentivo. Ao Prof. Kamel Zahed Filho pelos ensinamentos. Aos colegas do LabSid pelo companheirismo, em especial à Satie Ishikawa pelo carinho e à Silvana Susko Marcellini pela atenção. Às minhas queridas amigas de guerra, pelo incentivo, pelo carinho, pelo companheirismo e pelos melhores momentos desta jornada: Liliane Frosini Armelin pelas risadas, Mari Mitsuru Nishimura pela imensa ajuda, Nara Regina Leite pelo bom dia de todos os dias e Sandra Uemura pela cumplicidade. A todos os mestres e funcionários do Departamento de Engenharia Hidráulica e Sanitária da EPUSP pelo ambiente de amizade e aprendizado. Às instituições pela concessão de bolsas (FCTH, CNPq e Capes) e àqueles que de uma forma ou de outra me ajudaram. A todos, minha imensa gratidão.

One of the most important causes for poor water quality in urban rivers in Brazil is the low collection efficiency of the sewer system due to unforeseen interconnections with the stormwater drainage system. Since the beginning of the 20th century, Brazilian cities have adopted separate systems for sanitary sewers and stormwater runoff. Gradually these two systems became interconnected. A major challenge faced today by water managers in Brazil is to find efficient and low cost solutions to deal with this mixed system. The current situation poses an important threat to the improvement of the water quality in urban rivers and lakes. This article presents an evaluation of the water quality parameters and the diffuse pollution loads during rain events in the Pinheiros River, a tributary of the Tietê River in São Paulo. It also presents different types of integrated solutions for reducing the pollution impact of combined systems, based on the European experience in urban water management. An evaluation of their performance and a comparison with the separate system used in most Brazilian cities is also presented. The study is based on an extensive water quality monitoring program that was developed for a special investigation in the Pinheiros River and lasted 2.5 years. Samples were collected on a daily basis and water quality variables were analyzed on a daily, weekly or monthly basis. Two hundred water quality variables were monitored at 53 sampling points. During rain events, additional monitoring was carried out using an automated sampler. Pinheiros River is one of the most important rivers in the São Paulo Metropolitan Region and it is also a heavily polluted one.