Many of the artificial lakes in the river contain locks that made navigation possible. The cost of river transport usually lower than using roads. The waterway Tietê-Paraná is 2,400km long, and includes 1,100km between Conchas and São Simão, Goiás. One million tonnes of grain and 2 tons are transported annually.
The Tietê River suffers from high levels of pollution, however in the 1960's the problem was not so widespead, the river having many fish living within it. The causes of the pollution are said to be linked to the industrialisation of the city of São Paulo and the building of the Guarapiranga artificial lake. After the lake's construction, the Tietê river became redundant and was no longer used as the city's main water supply. Because of this the river was neglected, as maintenance procedures were suspended by the government.
In 1992 the city's inhabitants pressured the state government into trying to reverse the damage to the river. A petition was handed over with the support of over one million people which turned out to be the largest petition in Brazilian history. With finances from the IDB, a program named "Projeto Tietê" was started. With intense participation from NGOs, the level of wastewater treatment increased from 20% to 60%. It is expected that the program will reach at least 90% by its end.
The program also focuses on the industries within the vicinity of the river. At present 1,200 industries have agreed not to discharge their waste into the river. This corresponds to 90% of all the industrial pollution. From 1992 to 2006, the project spent over $1.5 billion.tributaries such as the Aricanduva River. The river has levees built alongside it that attempt to contain the increased volume of water. However, this area is poorly maintained and is normally occupied by squatters and filled with waste.
The problem of flooding is still far from resolved. It should be noted however, that there were no floods for three years from 2002 to 25 May 2005, when the second largest rainfall since 1943 struck the area. The government has started projects to prevent flooding, but they will not be completed until some time in 2008.