IO DE JANEIRO – In Brazil water and electricity go together, and two years of scant rainfall have left tens of millions of people on the verge of water and power rationing, boosting arguments for the need to fight deforestation in the Amazon rainforest.

Two-thirds of Brazil’s electricity comes from dammed rivers, whose water levels have dropped alarmingly. The crisis has triggered renewed concern over climate change and the need to reforest river banks, and has given rise to new debate about the country’s energy system.

“Energy sources must be diversified and we have to reduce dependency on hydroelectric stations and fossil fuel-powered thermoelectric plants, in order to deal with more and more frequent extreme climate events,” the vice president of the non-governmental Vitae Civilis Institute, Delcio Rodrigues, told Tierramérica.

Hydroelectricity accounted for nearly 90 percent of the country’s electric power until the 2001 “blackout”, which forced the authorities to adopt rationing measures for eight months. Since then, the more expensive and dirtier thermal power has grown, to create a more stable electricity supply.

Today, thermal plants, which are mainly fueled by oil, provide 28 percent of the country’s power, compared to the 66.3 percent that comes from hydroelectricity.

Advocates of hydropower call for a return to large dams, whose reservoirs have a capacity to weather lengthy droughts. The instability in supply is due, they argue, to the plants of the past, which could only retain water for a limited amount of time due to environmental regulations.

But “the biggest reservoir of water is forests,” said Rodrigues, explaining that without deforestation, which affects all watersheds, more water would be retained in the soil, which would keep levels up in the rivers.

“Forests are a source, means and end of water flows, because they produce continental atmospheric moisture and help rain infiltrate the soil, which accumulates water, and they protect reservoirs,” said climate researcher Antonio Donato Nobre.

“In the Amazon, 27 percent of the forest is affected by degradation and 20 percent by total clear-cutting,” said Nobre, with the Amazon Research Institute and the National Institute for Space Research.

That fuels forest fires. “Fires didn’t used to penetrate moist areas in the rainforest that were still green, but now they do; they advance into the forest, burning immense extensions of land,” he told Tierramérica.