Chinese political advisors have spoken out against excessive hydropower development to save the nation's rivers from potential environmental damage.

Excessive hydropower development could lead to ecological damage and deteriorating water quality, according to Liu Dehong, former vice director of the maritime bureau at the Ministry of Communications, and five other members of the National Committee of the Chinese People's Political Consultative Conference, the top political advisory body.

They blamed the record low water levels in the middle and lower reaches of the Yangtze River, the country's largest river, partly on the dozens of dams built on several of its tributaries including the Jinsha and Dadu rivers.

They said the relatively low reserves can no longer dilute pollutants as before, posing a threat to China's drinking water supply.

Large amounts of farmland, forest and wetlands have given way to excessive construction of hydroelectricity projects, which are often damaging the ecosystems, they said.

They said that the construction of too many dams goes against the concept of scientific and harmonious development and such projects often seek short-term economic returns at the cost of the environment.

Some dams on waterways like the Pearl River and Lancang River pose a threat to the life and property safety of the residents living nearby during flooding seasons, according to the advisors.

They suggested the governments set up strict environmental conservation criteria for the approval of new dam projects.