BEIJING -- The Three Gorges project has not deteriorated environment in Chongqing, a sprawling metropolis next to the project, Mayor Wang Hongju said Monday.

Water in the Chongqing section of the Yangtze River is clean and drinkable, "and the water quality is the best in Chinese cities at current," Wang, who is also a delegate to the ongoing 17th National Congress of the Communist Party of China (CPC), said on the sidelines of the congress.

The city also enjoys good air. It recorded 200 days with good air quality last year and may have more than 300 days this year, according to Wang.

The saying that the Three Gorges project has caused environmental disasters could not stand scrutiny, Wang added.

The Three Gorges dam has served as a barrier against seasonal floods threatening the lower reaches of the Yangtze River and the electricity generated by hydropower each year leads to a decrease of 100 million tons of carbon emissions.

Hu Jintao said Monday at the opening of the CPC congress that China's economic growth is realized at an excessively high cost of resources and the environment, before listing other difficulties and problems that hinder China's development.

China will promote conservation culture while moving to build a moderately prosperous society in all respects, said Hu while delivering a keynote political report.