Residents near the world’s fourth largest hydroelectric power plant say the Belo Monte dam has made their houses prone to floods of waste water

A line on the wall of Carlos Alves Moraes’ house shows the highwater mark of the flood which hit his neighbourhood in August. Houses near the lagoon are built on stilts to protect against seasonal rains, but now, because of the dam, they are prone to flooding throughout the year, he says.

“We spent 17 days in August living here with our feet under water,” he says.



Moraes, 52, lives in the Brazilian city of Altamira, in the shadow of the Belo Monte dam, the world’s fourth largest hydroelectric power plant. Six years after construction began – with another two years to go before it will be complete – controversy surrounding the project has not dimmed.



Facebook Twitter Pinterest Carlos Alves Moraes, whose house was flooded for 17 days in August. Photograph: Iuri Barcelos/Agência Pública

Moraes, of the Xipaia tribe, shares his two-room house with 10 others. All their furniture rests on stools – an attempt to protect it from the next downpour.



The neighbourhood, Jardim Independente I, has always suffered seasonal flooding. But residents say things have dramatically worsened since Belo Monte began operating in 2015, with the water rising higher and previously safe homes being inundated with water. The situation is dire; the water is contaminated with raw sewage and many inhabitants have contracted dengue fever.



More than 500 families live on this lagoon, which is now a well of waste. Without even basic sanitation, waste feeds straight into the water under the houses, and trash almost reaches people’s front doors. On the edge of the flooded area, an abandoned house is filled with water a metre deep, transforming it into a mosquito breeding ground.



“I got dengue and my neck never recovered,” says seamstress Maria de Fátima Damasceno Curuaia. “It started with a high fever and then pain spread throughout my body.” Almost everyone the Guardian talked to had had the fever, which recently killed a young man.



These people have struggled to be recognised as having been affected by Belo Monte, which would entitle its residents to compensation, or the right to move to one of five new communities built by Norte Energia, the company behind the dam. Three thousand families have already been rehoused, with many communities on stilts disappearing.



Facebook Twitter Pinterest Stilt-houses in Altamira, Brazil. Photograph: Mario Osava/IPS

The residents of Jardim Independente I were excluded from the resettlement scheme, which committed Norte Energia to rehome anyone living at less than 100m above sea level. This community is at 102m, according to the company. Now the firm, and Brazil’s National Water Agency, are assessing the effect of the filling of the reservoir, which began in November 2015, on the water table. Rulers and wells dot the community.



“This house was built in 1982. At the time, it did not flood,” says boat captain Raimundo Xipaia Curuaia. “Today water comes into the lounge, into the bedroom, into the whole house.” He leads us into one room he says is sinking. The floor makes a hollow sound when walked on and appears to be slightly curved.



Residents have demanded action from the Institute of Environment and Renewable Natural Resources. They argue that a condition of the dam being commissioned was to guarantee basic sanitation to the entire city of Altamira, and that the floods currently being suffered by the neighbourhoods on stilts are breaching that condition. Secondly, they say that the situation in Jardim Independente I has worsened after the activation of the dam. The population of the neighbourhood has grown, with many locals priced out – or flooded out – of other areas.



Ibama has ordered Norte Energia to do further research on the problems. “We know it’s only a first step, but it is good to have this recognition,” says resident Carlos Xipaia.



But some are not keen to move to the Collective Urban Resettlements put up by Norte Energia to rehouse 4,000 of the families displaced, according to the Movements of People Affected by the Dam (MAB). Dissatisfaction with the quality of the resettlement housing led to the legal suspension of the installation licence of the power plant in September.

Facebook Twitter Pinterest Residents says that raw sewage and other waste flows into their houses when the water rises. Photograph: Iuri Barcelos/Agência Pública

Xipaia hopes to be compensated in cash and not to be rehomed in a new community of buildings he considers to be of poor quality. “The houses are only three years old and the walls are already cracking, the floors rising. You cannot trust these houses,” he says. In a visit, our reporting team found loose flooring, cracks in the walls, leaks and complaints from the residents.

Norte Energia say they will spend $800m (£592m) on environmental measures. The whole dam was budgeted at $11.2bn. The company is paying for three hospitals, 30 health clinics and 66 education units.

The MAB has been aiding the mobilisation of the residents. “For us, an achievement would be simply not to have these houses flooded,” says Elisa Estronioli, a coordinator of the movement. “How can you ignore a community of this size that does not have sanitation?”

Norte Energia declined to comment.