Conservationists, however, argue that while hydropower does not produce greenhouse gases, too many dams could cause entire rivers to dry up in the summer. They point to the southern Carpathian Mountains, where about 500 hydroelectric power plants - some still being built - are located. The wild rapids at these sites are particularly lucrative for investors. At the same time, many of the projects are also located in conservation areas, and the damage to habitats is severe. Residents of the region are fighting to keep the remaining streams and rivers in Romania untouched.