Small Hydroelectric Dams Not So Green
By Mario Osava*
An attractive business with a reputation of being eco-friendly, small hydroelectric dams do pose some dangers to the environment, especially if there are many in the same river basin.
RIO DE JANEIRO, Aug 4 (Tierramérica).- The combined impacts of numerous small hydroelectric dams in one river basin can be at least as harmful as one large dam, warn experts, eco-activists and indigenous groups, who face a flood of new projects along the rivers of the western Brazilian state of Mato Grosso.
Hydraulic energy from small dams "is very interesting for its low environmental costs, but everything has its limits," says André Villas-Boas in reference to their proliferation along the tributaries of the Xingú River, in the Amazon.
At least six small dams are concentrated on the rivers in northeast Mato Grosso, points out Villas-Boas, coordinator of the Xingú Program of the non-governmental Socio-Environmental Institute (ISA). Two have already been built and a third has been given the green light by the energy and environmental authorities for the Culuene River alone, the main tributary of the Xingú.
Such projects should not be authorized without an integral assessment of the river basin in its environmental and social aspects, for a planned exploitation of the water resource as a whole, and limiting the number of hydroelectric dams, according to Villas-Boas, noting that more than half the area of the Xingú is indigenous land.
The dams are located around the Indigenous Park of the Xingú, a symbol of Brazil's indigenous policy that is home to some 5,000 people of 14 different ethnic groups.
Often included among "clean" sources of energy, small hydroelectric dams have become an attractive business for the "soft legislation" under fiscal and financial control and incentives, without duly considering that "they alter biological dynamics" in a serious way if there are many in one watershed, says Villas-Boas.
As a result, there are 240 small hydroelectric dams planned in Brazil, according to data from the National Electric Energy Agency (ANEEL). The 81 dams already under construction will produce 1,342 megawatts, or 17.29 percent of electricity from combined sources.
An example of a more unsustainable panorama is the Juruena River, according to Raul do Valle, an attorney who coordinates ISA's political and legal actions. In the Juruena basin, in northwest Mato Grosso, 83 hydroelectric dam plans have been registered. ANEEL suspended 30 projects in early July and decided to pursue integrated environmental evaluations.
There have been several cases where indigenous people have taken government officials or construction company employees hostage, in a bid to bring the work on dams on the Juruena and the Culuene rivers to a halt. In other efforts, lawyers have tried to do so through legal channels, obtaining temporary suspensions of construction permits. There are many cases where a final decision is still pending.
"We predict that there will be fewer fish" as a result of the energy projects on local rivers, begun around 10 years ago, because the dams "block the fish from swimming upriver for reproduction," said Paulo Kamaiurá, who has taken as his surname the name of his tribe, who live in the Xingú Park.
The affected rivers, which are already suffering contamination from agro-chemical runoff, flow towards the Park where they form the Xingú River, and as a result "the problems will be aggravated," said Kamaiurá, adding that it is essential to mobilize indigenous communities to raise awareness about the threats.
Because of their presumed limited ecological impact, environmental permits for small hydroelectric dams are granted by state, not federal, agencies. The state bodies are more vulnerable to local economic pressures, but they heed the national Brazilian Institute of Environment when the projects affect Indians, says Valle. In the cases of northern Mato Grosso, it is a matter of survival of native peoples, who rely on fish for their food, he adds.
That is the main argument against the dams in the legal cases that are still pending. The counter-argument of the construction companies and state authorities is that the indigenous groups do not suffer direct impacts, given that their lands are dozens of kilometers away from the dams.
But Valle stresses that there is no need for local production of electricity, given that the nearby cities are connected to the electrical network, so there is no justification for the "depredatory activity" in benefit of prívate profits. But the slow pace of justice favors the consummated fact, he admits, noting that it is nearly impossible to stop a dam after it has been built.
The dams reduce the quantity of fish in the rivers because they alter currents and nutrition, in addition to eliminating migratory species. Attempts to reestablish reproduction have not been successful, according to Juarez Pezzuti, a biologist who conducted a study of the effects of Paranatinga II, a small hydroelectric dam operating on the Culuene.
The impacts could be mitigated if there are prior studies and planning, and with participation of local communities, who are the ones left facing the threats and often do not benefit from the energy generated in their neighborhood, says Pezzuti, professor of advanced environmental research at the Federal University of Pará.
In another area of Brazil, in Santo Amaro da Imperatriz, a town in the southern state of Santa Catarina, a project of six small dams triggered reactions that led the local council to ban hydroelectric dams in the district, with only one vote against the majority.
The ban is unconstitutional, admits Environment Secretary Joao Renato Duarte. But "99 percent of the population is against" the dams and the project will only be approved if it can be verified that they will not harm the hot springs, waterfalls and rapids that attract tourism and provide recreation and cultural activities for local citizens, he said.
The hydroelectric dams are to be built using the latest European technologies, channeling only a portion of the river flow through tunnels, without affecting the landscape or the sport of river rafting, which is what feeds local tourism, says engineer Helio Machado, head of the project. The opposition is talking in absurdities, citing threats like flooding or that the Cubatão River will dry up, because they don't know the details, Machado says.
"It doesn't make sense to destroy the natural heritage" of the city in order to generate just 14 megawatts, retorts Eliazar Garbelotto, who runs a rafting business on the Cubatão.
The tourism sector is radically opposed to the small hydroelectric dams. There are five rafting businesses that bring in about 10,000 tourists per year, and employ just 50 people, but feed other tourist activities as well as providing environmental education, Garbelotto says.
* Mario Osava is an IPS correspondent.