"The current practice of using small hydropower plants has clearly proved to be environmentally unfriendly," Baiba Bumbiere, spokeswoman for the Latvian branch of global environmental pressure group WWF, told AFP.

"Damage caused by small hydropower plants stimulates the fragmentation of rivers, and damages and destroys the ecosystem."

Bumbiere said environmental campaigners had submitted a letter to the government earlier in the week requesting changes to the use of hydropower.

Prime Minister Indulis Emsis, from the Green Party, backed the introduction of small-scale hydropower when he was environment minister in 1993-98.

Most of the country's 150 small hydropower plants, now on 106 of its rivers, were built in the late 1990s. They were seen as a way to promote small businesses in the countryside because the electricity they produce is, by law, purchased for twice the price paid for power generated from other sources.

But environmentalists are now saying the plants, which provide just 1.0 to 1.5 percent of the total electricity consumed by the Baltic state, are damaging rivers and destroying fish stocks.

They say small fish are dying in power turbines and fluctuations in water level are producing dead zones along river banks. Rivers whose courses have been changed are becoming clogged up and 60 percent of river basins could be affected over the next 10 years, they warn.

"We have legislation but in many cases it is ignored," Bumbiere told AFP.

"There are small hydropower plants all around the world. But they must be tightly controlled and should be treated differently, because some of them damage rivers very badly," she said.

Environmentalists warned in an interview in leading daily Diena on Wednesday that they were considering reporting the situation to the European Union if the government failed to act.

"Even if the small hydropower plants are closed, the restoration of the ... rivers would require substantial resources and many years," Diena wrote.

Environment Minister Raimonds Vejonis told AFP he would propose changes to the way the plants operated.

"Plants would only be closed in an emergency," Vejonis said. "The best solution is to increase controls and fines. We are already working on changing the law."

"If we control small hydropower plants -- and I hope this will be done strictly -- there shouldn't be problems with the EU's environmental institutions," he said.

TERRA.WIRE