China's top legislature may revise a law to better prevent water pollution, by strengthening government responsibility and supervision, according to a draft released Monday.

Local governments should set time limits and make efforts to improve water quality, and will be authorized to issue tougher pollutant control requirements for water quality standards, according to the draft amendment of the Water Pollution Prevention Law, which was submitted to the Standing Committee of the National People's Congress for its first reading.

The draft says county and municipal-level governments should report plans for water quality improvement to higher levels of government, and make such plans public.

Environmental monitoring systems will be improved, with self-monitoring obligations of polluting enterprises specified in the draft.

The draft strengthens protection of drinking water, stating that emergency responses and back-up water sources should be built in cities with single water sources, and the quality of drinking water should be heavily monitored and relevant information made public.

Water pollution prevention in key fields, including industrial sewage, underground water, agriculture and rural areas, as well as pollution made by ships, should be strengthened, according to the draft.

The current Water Pollution Prevention Law was enacted in 1984 and amended in 1996 and 2008, and has played an important role in curbing water pollution, said Chen Jining, minister of environmental protection, at the opening meeting of the bi-monthly session of the top legislature.

During the 12th Five-year plan (2011-2015), China's chemical oxygen demand, a measure of organic pollutants in water, dropped by 12.9 percent, and emission of ammoniacal nitrogen shrank 13 percent, exceeding expectations.

However, Chen said, China still had severe problems with water pollution. The draft was made to ensure better implementation of a water pollution prevention plan issued by the State Council in April last year, Chen said.

The Ministry of Environmental Protection drew up the draft, which was approved by the State Council.