water management in the metropolitan region of são paulo water management in the metropolitan region of são paulo 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 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. the 7,917 hectares (19,560 acres) cantareira state park, created in 1962, protects a large part of the metropolitan são paulo 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. geography and climate greater são paulo area within the são paulo state. the climate of the mrsp is humid and subtropical, with temperatures ranging from highs of 30 °c (86 °f) during summer and lows of 15 °c (59 °f) during winter. rainfall is abundant, amounting to an annual average of 1,317 millimetres (51.9 in). it is especially common in the warmer months, and somewhat scant between june and august. the area covered by the mrsp is almost coterminous with the alto tietê basin. with a drainage area of 5,985 km² (2.4% of the state's territory), the basin encompasses 35 of the 39 municipalities and 99.5% of the population of greater são paulo. sector responsibilities the main stakeholders in water management in mrsp are the state government, the state water and sanitation utility sabesp and 35 municipal governments. a basin committee for the alto tietê basin, which supplies the other half of the water for the mrsp, brings together all stakeholders. the legal framework at the state level is based on two key federal laws, law 9,433 of 1997 concerning water resources management and law 11,445 of 2007 concerning water supply and sanitation. a key state law is law 7,663 of 1991 which created what is called the state system for water resource management. the system pioneered shared decision-making in water resources management even before the same principle was embodied in federal law. however, one of the most powerful actors in the system is sabesp and industries, which have little incentive to actively participate in the basin-level decision-making process. a main issue generating conflict since the beginning of water reform is over who receives the proceeds of bulk water pricing, once it will be implemented. some argue for centralization at the state level and others say that if basin committees and agencies should receive the revenues to become financially self-sufficient. the expected future revenues from water charging will only constitute 10 to 15% of needed investment. the difficulties in implementing this pricing system have delayed the advancement of the overall water management system. another important law is state complementary law 1,025 of 2007 concerning water supply and sanitation. 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 through a state council for water supply and sanitation (conesan). responsibility for policy and regulation the state government is a key stakeholder in the water sector. within the state government the state secretary for water supply, sanitation and energy (sse) is responsible for water supply and sanitation policy. the state secretary for the environment (sea) is responsible for environmental policy, including environmental aspects of water resources management through its water resources technical advisory team. the state water resources law, passed in 1991 by the state parliament foresaw the creation of twenty-two water basin management units (unidades de gerenciamento de recursos hídricos – ugrhis) at the state level, of which the alto tiete unit is one. these units are governed by committees with the participation of the state government, municipalities and civil society. the committees are supported administratively by basin agencies. the committees were expected to initiate a new approach in planning and management, with the key elements being licensing water resources use, charging for water use and dividing the costs of multiple-use interventions which have collective benefit. the são paulo state environment agency (cetesb) is responsible for issuing environmental permits and for monitoring and enforcing compliance with pollution laws in the state. created in the 1970s, it was one of the first environmental protection agencies in the country, and is widely respected in brazil and abroad for its technical competence. however, its command-and-control pollution regulations have been mostly limited to the state's largest industries and worst polluters, and as a result, some other players, such as the water and sanitation companies, have been subject to much weaker regulation and enforcement. the state has transformed the former gas and electricity regulator into a new gas, electricity and water supply and sanitation regulator in the new multi-sector regulatory agency arsesp (agencia reguladora de saneamento e energia do estado de são paulo). the agency organises public hearings, public consultation, and has an independent ombudsperson. master plans the first alto tietê water resources master plan was developed by the university of são paulo and was approved in 2003. the first master plan (i) clarifies the main watershed issues; (ii) evaluates water uses, availability, impacts and sustainability; (iii) delineates an action plan; (iv) decides investment priorities; and (v) provides an opportunity for discussion of common problems and for their resolution. the first water resources master plan focused on the issue of urban sprawl. the second plan, approved in 2009, deals primarily with the growing conflict over water. responsibility for service provision of the 35 municipalities in the alto tietê, 29 (representing 79 percent of the mrsp's urban population) receive their water and sewer services directly from the state water and sanitation company of são paulo sabesp. the other 6 municipalities receive treated bulk water from sabesp and distribute and bill for it via municipal utilities. throughout the state, sabesp provides water to 23 million people and sewage services to 19 million. it is one of the largest water utilities in the world, and it is listed on the new york stock exchange. the six municipalities in the mrsp not directly served by sabesp are: diadema (served by municipal company saned); santo andré (served by municipal company semasa); guarulhos (served by municipal company saae); mogi das cruzes (served by municipal company semae); mauá (served by a private operator under a municipal concession ecosama); and são caetano do sul (served by municipal