{"id":1652,"date":"2026-10-23T06:15:23","date_gmt":"2026-10-23T09:15:23","guid":{"rendered":"https:\/\/www.onthenet.com.br\/index.php\/2026\/10\/23\/billings-reservoir-history-power-plant-water-supply-and-the-challenges-facing-the-reservoir-that-connects-greater-abc\/"},"modified":"2026-10-23T06:42:32","modified_gmt":"2026-10-23T09:42:32","slug":"billings-reservoir-history-power-plant-water-supply-and-the-challenges-facing-the-reservoir-that-connects-greater-abc","status":"publish","type":"post","link":"https:\/\/www.onthenet.com.br\/index.php\/en\/2026\/10\/23\/billings-reservoir-history-power-plant-water-supply-and-the-challenges-facing-the-reservoir-that-connects-greater-abc\/","title":{"rendered":"Billings Reservoir: History, Power Plant, Water Supply and the Challenges Facing the Reservoir That Connects Greater ABC"},"content":{"rendered":"\n

The Billings Reservoir is one of the most striking landscapes in the S\u00e3o Paulo Metropolitan Region and, at the same time, one of the most misunderstood. For drivers on the Imigrantes highway or the Rodoanel, it is a sheet of water between hills. For people living in Ribeir\u00e3o Pires, Rio Grande da Serra, S\u00e3o Bernardo do Campo, Santo Andr\u00e9 or Diadema, it is leisure, scenery, a source of water and, often, a cause for concern. This guide brings together the reservoir\u2019s history, its role in power generation, its water supply, the laws that protect it and the problems that still threaten it.<\/p>\n\n\n\n

\"Atlantic
Atlantic Forest and the Billings Reservoir in S\u00e3o Bernardo do Campo. Photo: Lukaaz \/ Wikimedia Commons (CC BY 3.0).<\/figcaption><\/figure>\n\n\n\n

A reservoir built to generate power, not to supply water<\/h2>\n\n\n\n

The first surprise for many people is that Billings was not built to quench the region\u2019s thirst. It was built to generate electricity. The idea is tied to engineer Asa White Kenney Billings (1876\u20131949), who worked for Light, the company that supplied S\u00e3o Paulo\u2019s power at the time. According to Wikipedia, in 1923 he proposed damming the Rio Grande, also known as the Jurubatuba, instead of following the company\u2019s earlier plan. Di\u00e1rio do Grande ABC reports that the project is dated March 27, 1925, a date the newspaper treated as the reservoir\u2019s centennial in 2025.<\/p>\n\n\n\n

Construction advanced in stages. The Rio das Pedras dam began in 1925 and the area was flooded in 1927. In 1937, Light started the Rio Grande dam. In the 1940s, the Pedreira and Trai\u00e7\u00e3o pumping stations were built to increase the system\u2019s flow, a decision that brought serious environmental consequences, as we will see below. The name Billings, honoring the engineer, was adopted in 1949, according to Sesc. Since 1998, power generation has been operated by Emae, Light\u2019s successor in that area.<\/p>\n\n\n\n

How plateau water becomes electricity on the coast<\/h2>\n\n\n\n

The secret of the project is the terrain. Billings sits on the plateau, very close to the edge of the Serra do Mar. On the other side of the mountains is Cubat\u00e3o. The stored water is diverted through a canal and drops down the escarpment to the Henry Borden power plant at the foot of the range, using a vertical drop of about 720 meters.<\/p>\n\n\n\n

\"Pipelines
Pipelines of the Henry Borden power plant, which carry water from the plateau to the turbines, in Cubat\u00e3o. Photo: enioprado \/ Wikimedia Commons (CC BY-SA 3.0).<\/figcaption><\/figure>\n\n\n\n

The complex has two powerhouses, one external and one underground, with 14 generating units in total. The underground plant, dating from 1956, is listed by English-language Wikipedia with a capacity of about 880 MW. In a statement to Di\u00e1rio do Grande ABC, Admilson Barbosa of Emae stressed the reservoir\u2019s \u201cstrategic and multifunctional importance.\u201d<\/p>\n\n\n\n

A reservoir with eight arms, and numbers that vary by source<\/h2>\n\n\n\n

Billings has a highly indented shape, with eight main arms: Rio Grande, Rio Pequeno, Capivari, Pedra Branca, Taquacetuba, Boror\u00e9, Cocaia and Alvarenga. It touches, in whole or in part, the municipalities of S\u00e3o Paulo, Santo Andr\u00e9, S\u00e3o Bernardo do Campo, Diadema, Ribeir\u00e3o Pires and Rio Grande da Serra.<\/p>\n\n\n\n

When it comes to measuring the reservoir, each source gives a different figure, usually because they use different criteria. Di\u00e1rio do Grande ABC cites about 150 km\u00b2 of water surface and 463 km of shoreline. Portuguese-language Wikipedia gives 10,814 hectares (about 108 km\u00b2), the English version says 127 km\u00b2, and a Sesc text mentions 106.6 km\u00b2 and 995 million cubic meters of water. For that reason, this guide always attributes figures to their source and avoids settling on a single value.<\/p>\n\n\n\n

\"View
Billings seen from the area near the Imigrantes highway. Photo: Hamilton B. Furtado \/ Wikimedia Commons (CC BY 3.0).<\/figcaption><\/figure>\n\n\n\n

Where the water in ABC taps comes from<\/h2>\n\n\n\n

Although it was designed for energy, Billings came to supply people with water. Since 1958, the intake on the Rio Grande arm has provided drinking water. In 2000, the intake on the Taquacetuba arm went into operation. These are the only two stretches of the reservoir used by Sabesp for drinking water; the rest of the reservoir is not intended for consumption.<\/p>\n\n\n\n

To protect the Rio Grande arm, a barrier separating it from the main body of the reservoir was built in the early 1980s. The Rio Grande system has a capacity of about 11.21 billion liters, and its treatment plant produces roughly 5,500 liters per second, serving S\u00e3o Bernardo do Campo, Santo Andr\u00e9 and Diadema. According to Sabesp, the system supplies about 1.4 million people. Other publications cite 1.8 million or \u201cover 1 million,\u201d a difference that also depends on how people are counted.<\/p>\n\n\n\n

Pollution: a problem that began in the 1950s<\/h2>\n\n\n\n

The region\u2019s unplanned growth, mainly between the 1950s and 1970s, brought household sewage, industrial sewage and heavy metals into the reservoir. Another chapter was the pumping of Rio Pinheiros water into Billings. In 1992, reversing the Pinheiros into Billings was banned and, according to Wikipedia, a 2010 resolution again allowed pumping during periods of heavy rain.<\/p>\n\n\n\n

On July 13, 2009, Governor Jos\u00e9 Serra signed, in Rio Grande da Serra, State Law No. 13,579, which defines the Billings Watershed Protection and Recovery Area (APRM-B). The law requires, among other measures, that homes be connected to the sewage network, and sets a 50-meter restricted strip from the maximum operating level. Environmental lawyer Virg\u00edlio Alcides de Farias, of the Movimento em Defesa da Vida do Grande ABC, notes that Billings\u2019 waters are classified as classes 1 and 2, which prohibits sewage discharge, even treated sewage.<\/p>\n\n\n\n

Experts quoted in the press are cautious. Professor Renata Maria Moreira of UFABC believes improvement will not be quick. Farias warns that, without action, the central area of the reservoir could become a polluted receptor in about 50 years.<\/p>\n\n\n\n

Billings in 2026: sewage, algae and the Rio Pequeno project<\/h2>\n\n\n\n

Two recent news stories show the reservoir remains at the center of the debate. The first concerns water quality. A report by USCS (Municipal University of S\u00e3o Caetano do Sul), commissioned by the Rio Grande da Serra city government and produced in November 2025, mapped 16 points of irregular sewage discharge into water bodies that feed the Rio Grande arm. The Water Quality Index at those points was rated \u201cvery poor.\u201d The city identified more than 30 areas with sewage flowing directly into streams, 16 of them in critical condition. USCS biologist Marta Marcondes highlighted the presence of many disease-causing microorganisms.<\/p>\n\n\n\n

The Di\u00e1rio do Grande ABC report of March 27, 2026 also shows the authorities\u2019 response. According to Mayor Akira Auriani, Sabesp committed to bringing forward universal sewage treatment in the city from 2030 to 2028, with R$ 400 million in investment. The state Secretariat for the Environment, Infrastructure and Logistics (Semil) confirmed the irregular points and said Cetesb is carrying out inspections; universal sanitation is set for 2029 under the concession contract. In Santo Andr\u00e9, an arm near Jardim Miami and Riviera shows a heavy concentration of algae, known as macrophytes, which multiply in highly polluted environments, along with solid waste.<\/p>\n\n\n\n

\"View
Billings in 2024. Photo: Erick Soares3 \/ Wikimedia Commons (CC BY-SA 4.0).<\/figcaption><\/figure>\n\n\n\n

The second story is the Rio Pequeno water transfer. On January 21, 2026, Sabesp began works to link the Billings system to the Alto Tiet\u00ea system. The project plans to draw water from the Rio Pequeno arms in S\u00e3o Bernardo and pump it to the Taia\u00e7upeba Reservoir in Suzano through a buried steel pipeline of about 38.1 km, with an intake of 4,000 liters per second and an investment of R$ 1.4 billion. The route crosses Santo Andr\u00e9, S\u00e3o Bernardo, Ribeir\u00e3o Pires, Rio Grande da Serra, Suzano and Mogi das Cruzes.<\/p>\n\n\n\n

Sabesp says the work responds to scarce rainfall and is part of the Water Security Plan, which runs to 2060. Director Marcel Costa said eight routes were analyzed, that the chosen one is the most environmentally suitable, runs along public roads and holds a Cetesb license. Semil said a study by FCTH, at USP, confirms the intake is viable. On the other side, Marta Marcondes questions the impact on vegetation and on the springs that feed the Rio Grande arm, as well as the lack of public hearings, and recalls that an emergency interconnection built in 2014\u20132015 allegedly silted up about 1 km of that arm. The Rio Grande da Serra city government and its Municipal Environment Council also voiced concern, and Santo Andr\u00e9\u2019s Semasa pointed to technical inconsistencies in Sabesp\u2019s assessment. The debate is ongoing and worth following.<\/p>\n\n\n\n

Leisure, fishing and water sports: Billings is also for enjoying<\/h2>\n\n\n\n

Despite its problems, the reservoir remains one of the most prized leisure settings in the region, with small beaches, viewpoints, restaurants, sport fishing and water sports. Fish mentioned by the sources include tilapia, lambari, carp and tra\u00edra. To find out where to sail, kayak, stand-up paddle and fish, what precautions to take and how to get there, read our guide to water sports, fishing and leisure at the Billings Reservoir<\/a>.<\/p>\n\n\n\n

\"Riacho
Riacho Grande beach in S\u00e3o Bernardo do Campo. Photo: Andre Pimentel \/ Wikimedia Commons (CC BY-SA 3.0).<\/figcaption><\/figure>\n\n\n\n

If you want to turn the outing into a full weekend, you can combine the reservoir with other nearby destinations. Our complete guide to Ribeir\u00e3o Pires<\/a> covers attractions, food and itineraries, and the Paranapiacaba guide<\/a> shows the English-style village in the Serra do Mar, just a few kilometers away.<\/p>\n\n\n\n

Summary: what you need to know about Billings<\/h2>\n\n\n\n