BEIJING - China still has vast potentials to develop small hydropower plants but better management should be in place to minimize their environmental impact, officials said on Sunday.

China had 47,000 small hydropower stations, each with an installed capacity of less than 50,000 kilowatts, at the end of last year, said Tian Zhongxing, an official with the Ministry of Water Resources (MWR).

The aggregate installed capacity of the small hydropower stations hit 73 million kW with an annual electricity output of 220 billion kWh, which accounted for one fourth of China's total hydropower output.

However, the small stations represent only 41 percent of China's small hydropower potential, lagging far behind developed countries, Tian said. The rate stood at 97 percent in Switzerland and France, 96 percent in Spain and Italy, and 84 percent in Japan.

Tian called for more efforts to develop hydropower as most of China's untapped hydro resources are based in 832 impoverished counties. Related projects can stimulate local economic growth.

There are dissenting voices on the construction of small hydropower stations. But the environmental impact, such as soil erosion, is resulted from a lack of oversight and management, said Liu Huan, director of the International Center of Small Hydro Power under the MWR.

"With scientific planning and management, we can minimize or even eliminate the adverse effect on the environment," Tian said.

China aims to bring the installed capacity of small hydropower stations to 75 million kW by 2020.