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Water management in the Metropolitan Region of São Paulo, Brazil faces several challenges, including pollution of drinking water reservoirs that are surrounded by slums, water scarcity leading to conflicts with the Campinas Metropolitan area to the north, inefficient water use, and flooding. The sprawling Metropolitan Region of São Paulo (MRSP) with close to 20 million people is the seventh most populous urban area in the world〔List of metropolitan areas by population, accessed on April 2, 2009〕 and the economic, financial and technical hub of Brazil. The main stakeholders in water management in MRSP are the state government, the state water and sanitation utility Sabesp and 39 municipal governments. A basin committee for the Alto Tietê basin, which covers the entire area of the MRSP and supplies half of its water, brings together all stakeholders. It has drawn up two master plans for the management of water resources in the basin. The first was approved in 2003 and focused on urban sprawl. The second was approved in 2009 and focused on water use conflicts. Together the stakeholders have addressed the challenges mentioned above through massive investments in wastewater collection and treatment and slum upgrading. In the future new water sources are being developed from the Iguape river in the Ribeira valley 80 km to the south of MRSP. Furthermore, the efficiency of existing water use is expected to be increased through more reuse of treated wastewater and further reductions in water losses. ==History== The first modern water supply system for São Paulo was built by a private company, the Cantareira Water Supply and Drainage Company of the City of São Paulo, in the 1880s. The company built a pipeline from the Cantareira mountains in the North to São Paulo, which would become the first element of what would later become the Cantareira system which now supplies half the water of Greater São Paulo. After the concession for the private Cantareira Water Supply and Drainage Company of the City of São Paulo had ended, the responsibility for water supply was taken over by the municipalities in the metropolitan area of São Paulo. In the early 20th century another private company, the São Paulo Tramway, Light and Power Company, built two dams on the Upper Tiete river upstream of what was then the city of São Paulo to produce electricity from hydropower for the growing city. The first was the Guarapiranga reservoir completed in 1906, followed by the Billings reservoir completed in 1935. Both reservoirs were initially used only for hydropower, but beginning in 1928 the Guarapiranga was also used for drinking water supply. As the city grew further, the Billings reservoir was also used for drinking water supply. In the 1970s the government of the state of São Paulo took a much more active role in water management. As in other Brazilian states at the time, a state water supply and sanitation company was established. The company, Sabesp, took over the responsibility for water supply and sanitation from most municipalities in the metropolitan area and in the rest of the state. At the same time, a State Environmental Agency CETESB was created, being one of the first such agencies in Latin America. Among the first environmental measures was the state headwater protection law, which prohibited high-density residential occupation in 53% of Greater São Paulo.〔 Also, the first wastewater collection and treatment systems were built. However, the measures proved to be ineffective. Slums spread on the shores of the Guarapiranga and Billings reservoirs, and the reservoirs were severely polluted. In 1986 the first slum upgrading program by the city of São Paulo began, all while more slums sprang up at the fringes of the metropolitan area.〔 In 1990 a radio programme called “The Meeting of the Rivers” compared the Tiete River to the River Thames in the 19th century and called for action to clean up the river. One year later, the state parliament passed a State Water Resources Law, the first of its kind in Brazil. It foresaw the creation of basin committees for 22 basins in the entire state, including one for the most polluted basin, the Alto Tiete. At the same time a petition that called for cleaning up the Tiete River was signed by 1.2 million signatories. Subsequently, the slum upgrading program was expanded to include the slums on the shores of the Guarapiranga reservoir, with the support of the World Bank and the Inter-American Development Bank. However, in order to address pollution in the river, various entities had to work together: Sabesp was in charge of water supply and sanitation; municipalities were in charge of zoning, building permit and solid waste management; and CETESB was in charge of regulating industries that discharged their wastewater into the river. In order to better coordinate the efforts of these entities, the Alto-Tietê Basin Committee was established in 1994. It initiated the First Alto Tiete Water Resources Master Plan, which addressed the issue of urban sprawl and was approved in 2003.〔 In 2007 the state government passed the State Complementary Law 1,025 that established a State Council for Water Supply and Sanitation CONESAN to better coordinate the efforts by the state government, Sabesp and municipalities. The law strengthens the State’s regulatory and enforcement role, integrates planning and implementation activities, and promotes collaboration between the state, municipalities and civil society by creating a State Council for water supply and sanitation (CONESAN). Numerous initiatives were subsequently launched, such as the R$200 million ''Córrego Limpo'' (Clean Stream) program started by São Paulo municipality in 2007.〔 A program to control water losses by Sabesp was set up in 2008. The ''Pacto de Aguas'' (Water Deal) by the State Environment Secretariat in 2009 was another program meant to engage all 645 municipalities in the state.〔 In the same year, the Second Alto Tiete Water Resources Master Plan, which addressed the issue of water conflicts between various uses and stakeholders, was approved.〔 Despite these substantial efforts, it has not been possible to entirely clean up the river because new source of pollution emerged in the rapidly growing metropolitan area as older ones were brought under control. As of 2011, 55% of the municipal wastewater in São Paulo is being treated compared to only 20% twenty years earlier. The Tiete River is still biologically dead within the metropolitan area and as far as Salto 100 km downstream. Twenty years earlier the severe pollution extended until Barra Bonita, 260 km downstream.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Water management in the Metropolitan Region of São Paulo」の詳細全文を読む スポンサード リンク
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