Piracicaba River (Minas Gerais)

The most popular version for the origin of the river's name is that the term "Piracicaba" was borrowed from Tupi-Guarani and interpreted as "place where the fish stop". This would be an allusion to the significant number of small falls found in some sections of the riverbed, especially in the Antônio Dias region, which disrupt the fish traffic. This argument also explains the origin of the São Paulo Piracicaba River's name. Another popular version states that "Piracicaba" in Tupi-Guarani means "river without fish", but the application of this interpretation to the Piracicaba River is questionable, given that in the past it was a river with plenty of fish. ==History==

Exploration and mining The region between the mouths of the Piracicaba and Manhuaçu Rivers, i.e. between Ipatinga and Aimorés, was originally inhabited by the Aimoré peoples. Attempts to explore the Doce River Valley in search of mineral riches began in the 16th century, but were unsuccessful, which ended up delaying the settlement of the area. The expedition of Sebastião Fernandes Tourinho (1573) entered the course of the Doce River and some of its tributaries, calling the region at the mouth of the Piracicaba River the ‘Green Valley’, due to the dense forest. Towards the end of the 17th century, the discovery of gold at the headwaters of Das Velhas and Piracicaba rivers, in Ouro Preto, encouraged expeditions of bandeirantes from São Paulo to explore those areas and then explore downstream. The search for gold led to the establishment of settlements in Ouro Preto and Mariana. In the early 18th century there were also settlements on the Piracicaba river banks in Catas Altas, Santa Bárbara, Nova Era (formerly São José da Lagoa), Rio Piracicaba (formerly São Miguel do Rio Piracicaba) and Antônio Dias. In addition to mineral extraction, cattle ranches and small factories could be found along the river. Mining was Brazil's main economic activity in the 18th century, but its rise led to the first environmental impacts on the rivers in the affected areas, including the Piracicaba. Colonisation progress , one of the oldest settlements on its banks The Rio Doce Valley used to be on a route for the precious stones mined in the central region of Minas Gerais, linking the Royal Road in Diamantina to the coast of Espírito Santo for export. As a result, the royal crown banned settlement and new roads in the region to prevent the gold from being smuggled down the Doce River and its tributaries, such as the Piracicaba. In an attempt to keep outsiders away, the lands were described as having dense vegetation and venomous animals, with a predominance of the ferocious Aimoré. However, settlement was authorised in 1755, after Minas Gerais experienced a decline in gold production. Despite the decline in gold availability, the mineral diversity fuelled the maintenance of mining activity in the Ouro Preto region, including in the Piracicaba riverbed, over the following centuries. Once settlement was authorised, the Aimoré were massacred so that outsiders could conquer the land. Under these circumstances, native attacks on settlements became constant, forcing the colonists to abandon their farms and livestock. The natives, in turn, faced military punishments, such as the expedition of Luís Diogo Lobo da Silva in the 1760s, then governor of the . The administrator and his troop of 150 armed men navigated the rivers Piracicaba and Doce as far as Cuité (now Conselheiro Pena) in an act of repression against the natives. The railway follows the course of the Doce and Piracicaba rivers for the majority of its length, resulting in increased population growth on the banks of these rivers. As a result, environmental transformations in the region intensified. Urbanisation and environmental degradation The existence of a railway, watercourses and forests for timber extraction were decisive factors in the establishment of Acesita in Timóteo in 1944 and Usiminas in Ipatinga, near Coronel Fabriciano in 1956. In 1951, to provide the company with electricity, Acesita built the Sá Carvalho Hydroelectric Power Station, located on the Piracicaba River in Antônio Dias, the largest hydroelectric power station in Minas Gerais at the time. Throughout the second half of the 20th century, the urban centres of João Monlevade and the Steel Valley kept growing due to industrialisation, as well as the expansion of eucalyptus monoculture to meet the needs of the power plants. Consequently, the dumping of urban and industrial effluents into the waters was intensified, a situation aggravated by the construction of new hydroelectric power stations along the river, extensive land use and mining. Flooding was also a major problem thanks to unbridled occupation of risk areas. On the other hand, there have been some efforts to reduce degradation, such as the implementation of riparian forest along the river mouth by Usiminas in the 1990s; the creation of the Piracicaba River Basin Committee (CBH) under the State Water Resources Policy on 17 February 2000; and the construction of wastewater treatment stations in some cities. and severe droughts. == Geographical aspects ==

Drainage and climate The Piracicaba River rises on one of the peaks of the Caraça mountain range at an altitude of metres, in the district of São Bartolomeu, which belongs to Ouro Preto. It runs for a total of 241 kilometres to its mouth on the left bank of the Doce River, of which it is one of the main tributaries, between the municipalities of Ipatinga and Timóteo, The Cwa classification, on the other hand, is found in most of the basin, in its central area. The Aw climate is recorded in the Steel Valley, at the mouth of the Piracicaba River, It is worth noting that during the rainy season it is also common for water turbidity to rise, due to the faster current and the intensified movement of sediment, humus and plankton. The headwaters of the spring have the highest altitudes in the basin, reaching at the Sol peak, in the Caraça mountain range. This is considered an enclave of the Espinhaço mountain range in the middle of the Iron Quadrangle due to its similar characteristics Susceptibility to erosion is classified as "strong" or "very strong" in 66% of the basin area, a trait that is particularly accentuated at the headwaters of the Santa Bárbara river sub-basin and at the headwaters of the Piracicaba itself. The headwaters are where the highest sediment production occurs, with an average of 100 to 200 tonnes per square kilometre per year (t/km²). Industrialised mining in the headwaters region contributes to sediment formation, facilitating siltation. Heavy rainfall events and prolonged droughts naturally intensify the erosion process. Downstream of the confluence of the Piracicaba and Doce rivers, sediment generation is relatively low, at around 50 t/km² per year, but the Piracicaba river basin is one of the largest sediment producers in the Doce river basin. Biodiversity and soil use silicon slag deposit in Ipatinga, with the Piracicaba river in the background. The original predominant biome in the basin area is the Atlantic Forest, with a small representation of the Cerrado at the western end. In the Espinhaço mountain range, due to the altitude, the vegetation becomes variable with altitude fields and rupestrian grasslands in association with the Cerrado. However, the land cover has changed considerably due to the economic activities carried out in the region, especially in the Steel Valley Metropolitan Region, which is one of the state's main steel hubs. In addition, the land has been used for livestock farming and eucalyptus reforestation, although most of the native forest was cleared during the 20th century as a result of farming and timber extraction for charcoal production. Later, these areas were used to grow eucalyptus. Out of the total area of the basin, around 48.88% is made up of pasture, 35.7% of seasonal semi-deciduous forest, 7.56% of reforestation, 2.3% of crops and towns, 0.36% of water bodies, 0.29% of savannah, 0.02% of and 4.89% of other uses. It should be emphasised, however, that the percentage of natural forest cover is distributed in isolated spots in non-devastated areas. According to 2011 data, the Piracicaba River's fish fauna is made up of around 40 species, less than half of the 99 reported in the Doce River basin. The environmental transformations undergone by the basin region throughout its history have caused a significant reduction in the availability of species. The piau-vermelho (Leporinus copelandii) is an example that could be found until the 1930s, while the pipitinga was more popular until the 1970s, although rare specimens of both can still be found. Natural river rapids and hydroelectric power stations are also obstacles that interfere with the flow and distribution of fish. The reduction in variety led to the introduction of foreign species by the local population from the 20th century onwards, known as peixamentos. The first of these was the introduction of the mandí-amarelo, brought from the in 1961. This process was often uncontrolled, generating conflicts with native species, such as competition between fish and predation. Surveillance is carried out in some places that are frequently used for fishing, as it has been in the Guilman Amorim HPP lake since the 90s. In addition, most of the species used for fishing in the river are exotic, particularly carp, dorado and tilapia. Other examples of species found are catfish, pearl cichlid, cascudo, cumbaca, lambari, muçum, sarapó, traíra and trairão. == Socio-economic participation ==

Demographics The Piracicaba River basin covers all or part of 21 municipalities, The activity is mainly carried out by the local population and in an amateur way, but according to the ‘state fishing law’, approved in 2002, fishermen must have a ‘fisherman's licence’, issued by the State Forestry Institute (IEF), whether they are fishing from the banks or from boats. Any boat used must also be registered. During the piracema period, which normally runs from 1 November to 28 February, stricter restrictions are applied to encourage the fish to travel to the headwaters to reproduce. In addition to fishing, the waters of the spring are used for recreation by people living along the banks, but the excess of pollutants is a health risk and drownings occasionally occur. Another form of use is for informal transport in canoes between nearby towns, to shorten land routes. Economy . Around 53% of the Gross domestic product (GDP) of the municipalities in the river's catchment area comes from the industrial sector, while 35% is added by trade and/or services and 1% by agriculture. The remaining 11% comes from other activities. is the largest in terms of power generated. == Ecology and the environment ==

Degradation of the river banks between Antônio Dias and Timóteo, seen from the BR-381 bridge. At the same time as the area covered by native forest is dissolving in isolated spots that have not been devastated, the river and its tributaries have been severely punished by pollution generated from waste caused by local industries, including in the Piracicaba river basin. The greatest impacts on the riverbed would occur if the Upper South Dam at the Gongo Soco mine in Barão de Cocais, belonging to Vale, were to break, which was identified as being at risk of collapse due to the instability of the northern slope of its pit. The collapse could generate a wave of mud that would reach the Piracicaba River via the Santa Bárbara River and then the Doce River, which was already affected by the dam collapse in Mariana in 2015. The mud would destroy 383 hectares of native Atlantic Forest, cause soil infertility in the affected areas and jeopardise the operation of hydroelectric power plants. As a result, the dam was closed, preventive evacuations were carried out in the surrounding areas and decommissioning began. By June 2019, this and 32 other dams had been closed in the state, including in Ouro Preto, Mariana, Rio Piracicaba and Itabira. Large-scale eucalyptus plantations, in turn, have led to a profound change in the natural landscape, as vast areas are occupied by the same species of plantation. This has reduced the region's forest ecosystem and increased the risk of pests. In addition, the use of fertilisers and pesticides is necessary to guarantee productivity. After planting and felling, there is a risk of erosion due to the rugged terrain and of pesticides flowing into watercourses, which also favours siltation. In terms of socio-economic aspects, eucalyptus began to occupy areas previously used by local agriculture, weakening the production and marketing of local products. Rural communities also began to depend almost exclusively on these crops, altering the local social and cultural context. Deforestation, on the other hand, intensifies soil runoff, altering drainage characteristics and reducing the capacity of the soil and aquifers to retain water. The Piracicaba River Basin Committee predicted in 2015 that if these conditions prevail, the river could dry up by 2030. Treatment and conservation According to Vale, the company keeps the spring area preserved and treats all the water before it is discharged into the spring, in the same way that Samarco claims to do. ArcelorMittal Aços Longos, in João Monlevade, also claims to treat or reuse all the water from its plant. The water used by Aperam South America and Usiminas, located in Timóteo and Ipatinga respectively, is extracted and treated from the river by the companies themselves, while the effluent is reused or released into the same stream after undergoing treatment plants. Cenibra, one of the main eucalyptus producers in the region for pulp production at its factory, claims to regularly carry out technical, economic, environmental and social planning to diagnose and propose measures to mitigate the environmental impacts generated. The company also claims to provide previously non-existent infrastructure and housing in the areas where it operates, as well as carrying out support programmes and discussions with the communities. According to 2010 data, 84.6% of the sewage produced by the municipalities in the basin is collected, but only 19.4% is treated. Catas Altas, Ipatinga and Itabira were the only cities to treat 100% of their sewage. In addition, 79.9 per cent of solid waste was properly disposed. In the same year, the operation of a sewage treatment plant in the Limoeiro neighbourhood in Timóteo was authorised, with the initial intention of serving 165,000 inhabitants of the city and neighbouring Coronel Fabriciano. The basin also has several water quality monitoring stations run by IGAM, with regular analyses of physical-chemical and biological parameters. There are also environmental protection areas (APAs) along the course of the river that are only mapped out, with no management measures in place. It is also worth highlighting research activities regarding the river's conditions carried out by educational institutions and universities in the region. == Popular culture ==

over the Piracicaba river, as seen from Coronel Fabriciano Although degraded, the Piracicaba River is still a part of the daily life of residents around its course, whether through its direct use or solely through its physical existence. The river is directly linked to the history of the towns that developed on its banks, and is even referenced in the municipality's name of Rio Piracicaba. This, in turn, was inherited from its former name, São Miguel do Rio Piracicaba, dating back to the 18th century. Along with the historical context, the spring is added to various landscapes that contain individual and collective meanings for nearby residents, instigating memories and recollections. It also marks the denomination of the region known as ‘Médio Piracicaba’, or even ‘Médio Piracicaba micro-region’, which includes a total of 17 towns that have common historical origins, socio-cultural context and geographical aspects, as well as diverse cultural assets and manifestations. One of the municipalities in the Middle Piracicaba is São Gonçalo do Rio Abaixo, where the Lavadeiras da Prainha group, considered to be the municipality's intangible heritage, brings together dozens of ladies who depended on the region's waters for diverse daily activities, such as washing clothes and pots, while singing songs. The river most used in this town was the Santa Bárbara, one of the main tributaries of the Piracicaba river, All of this scenery is sometimes exalted in local cultural manifestations, such as paintings, music, or media publications. In 2019, restoration work began on the ruins of Pedra Mole Station in Ipatinga. This was the first EFVM railway station in the Steel Valley, dating back to 1922, but it was deactivated less than five years later due to the instability of the soil at the site, which led to the displacement of this section of the railway. Located close to the mouth of the Piracicaba River, it has remained in a state of abandonment in the middle of closed forest ever since, but the restoration of the station in 2019 included the construction of a deck to view the meeting of the Piracicaba and Doce rivers. ==See also==