Friends of the river
Works aimed at preventing floods and changing the landscape are creating a new relationship between São Paulo residents and the Tietê Deepening the Tietê Riverbed (Phase II)
written by ◦ Miúcha de Andrade photos by ◦ Luciana De Francesco

Every day, José Milton de Lima, 44, travels 12 km on the Tietê River in just 20 minutes. A launch captain, he has been making the trip several times a day for seven months, transporting the government authorities and engineers who are supervising the Tietê River Deepening Project, which began two and a half years ago. In the course of his job, José Milton is in a better position than most São Paulo residents to observe the first changes resulting from the second stage of the project. Instead of trash, waste and clandestine sewers, a 50-km garden is gaining ground on the banks of the Tietê.

Working through its subsidiary CBPO Engenharia, Odebrecht is one of the contractors engaged in the challenge of preventing urban floods caused by the Tietê and changing the landscape of a symbol of São Paulo. The project is being carried out in two stages. Phase I, begun in December 1998 and completed in December 2000, added another 2.5 meters to the depth of a 16-km stretch of the river, between the Cebolão interchange and the Edgar de Souza Dam reservoir. Phase II of the project, which began in March 2002, involves deepening a 24.5-km section between Cebolão and the Penha Dam, which will be the same depth as the stretch included in Phase I. Ten thousand trees and shrubs will also be planted, together with natural vegetation covering a 220,000 sq.m. area along the riverside expressways.

São Paulo Governor Geraldo Alckmin and Japanese Prime Minister Junichiro Koizumi planted a brazilwood tree to mark this new stage of the BRL 700-million project, which is financed by resources from Japan Bank International Cooperation (JBIC) and the State of São Paulo (75% and 25%, respectively).

The progress being made is clearly visible from the Tietê Riverside Expressway – 70% of the schedule has already been completed. The old metal guardrails have been replaced with safer concrete or “New Jersey” highway barriers.

Thanks to the excavation and widening of the riverbed by up to 45 meters, summer rains no longer present a threat for São Paulo residents, and flooding on the Tietê Riverside Expressway is a thing of the past. One of the city’s main road arteries, it used to be closed to traffic whenever a heavy rainstorm hit the area.

The contractor’s teams have removed 6 million cu.m. of soil and 800,000 cu.m. of rock, as well as 120,000 tires and 11,000 tonnes of trash and waste. “We can’t say that flooding will never happen again, but it is only expected to recur a century from now. This will improve the city’s macro-drainage because the Tietê is like a drain for São Paulo – all the other rivers flow into it,” observes Governor Geraldo Alckmin.

Like José Milton, the governor has had a first-hand look at the progress made on this project, and explains what the next steps will be: “A 40 km stretch of the river is going to be navigable by the end of the year. Once the lock at Cebolão has been built, we will have a waterway that can be used to transport river sediment by barge instead of using trucks. That will reduce traffic on the riverside routes.”

Construction of São Paulo’s first lock and bottom spillway will make river transportation possible. That job is the responsibility of the Calha 2 Joint-Venture, led by Odebrecht. The bottom spillway regulates the level of the river. Its two large sluice gates are closed when the Tietê is too low for navigation, and opened to drain off excess water when it rains in summer. The lock can raise and lower up to two barges at a time. Each barge can carry as much as 150 tonnes of waste, the equivalent of 20 truckloads. Estimates are that 800,000 tonnes of silt and waste per year are deposited in the river.

According to Odebrecht Contract Director Márcio Pellegrini, “Working here is particularly significant for us, because CBPO built the Cebolão interchange 20 years ago and that was a watershed in São Paulo’s history. Now here we are again. We take great pride in preventing flooding on the riverbanks and having another opportunity to change the city for the better.”

The work never stops. The 1,050 people hired for this project are working three shifts around the clock. Now that the flooding problem has been solved, São Paulo residents are seeing a significant change in the landscape. “Here in Lot 1, we get traffic coming in from the Castelo Branco, Anhanguera, Dutra, Fernão Dias and Raposo Tavares highways. Over 100,000 vehicles enter and leave the city every day. The area used to be unsightly because of the dense vegetation growing wild along the riverbanks, but now plants are growing there, creating a healthier atmosphere,” says Márcio Pellegrini.

José Milton de Lima agrees. He dreams of the day when the Tietê River will be a tourist attraction in his city. “You can’t imagine how beautiful it is on the river on a sunny afternoon. An area that used to be an eyesore is turning into something beautiful.”