The delegation from Yunnan province to the National People's Congress plans to call on the central government to strengthen its support of the province, a key source region for watercourses in Southwest China and Southeast Asia, to help it gain better control over its water pollution issues.

The suggestion the delegation plans to submit to the country's top legislature highlights Yunnan's special role in ensuring the security of waters in China and beyond, as well as the challenges the province faces with the governance of its water resources.

Yunnan is the source region or the key upstream area for six major domestic and international rivers — the Yangtze, Pearl, Lancang, Nujiang, Honghe and Irrawaddyit said.

Known as the Mekong River in Southeast Asia, the Lancang is a vital waterway that stretches across China, Laos, Myanmar, Thailand, Cambodia and Vietnam.

Originating in Qinghai province, the river flows through Yunnan into Myanmar. The suggestion said Yunnan has seen significant progress in improving its water environment and has thus made great contributions to the development of downstream regions in China and Southeast Asian countries.

In 2021, the proportion of surface water of fairly good quality in the province reached 89.6 percent, compared to the national average of 84.9 percent, it said.

China has a five-tier quality system for surface water, with Grade I being the best. The quality of surface water is determined to be fairly good if it reaches Grade III.

The province saw its proportion of fairly good-quality water climb further to 90.5 percent in 2022, according to the Yunnan Department of Environment and Ecology.

The suggestion said the quality of all the water that flows out of Yunnan in the six river basins reached Grade II in 2021.

"Due to landforms and inadequate environmental infrastructure, however, the water quality in some areas and river basins in the province remains poor," it said. "With a large proportion of monitoring sections still reporting water quality below Grade V, the province is facing huge difficulties in tackling water pollution."

Many water resources in Yunnan are concentrated in gorges that are not accessible to nearby areas, it said.

The problem is especially prominent in central Yunnan. The amount of water resources per capita in the area is only 700 cubic meters.

According to the United Nations, an area is experiencing water stress when annual water supplies drop below 1,700 cu m per person.

The suggestion said two-thirds of Yunnan's population and one-third of its farmland are located in small plains scattered among mountainous areas, which cover only 6 percent of the area under its jurisdiction.

This has resulted in serious water pollution in some small plains, it added. No more than 60 percent of domestic wastewater is collected for disposal in urban areas in Yunnan, and only 38 percent in rural areas.

Limited land resources in the province have also made building infrastructure for water pollution control challenging. While riparian buffers, which are areas along shorelines where development is restricted or prohibited, and artificial wetlands are widely used in central and eastern China for water pollution treatment, there is essentially no land available in Yunnan to develop them.

"Yunnan urgently needs support from the central government," the suggestion said.

The central government allocates special funding for water pollution control every year. The funds, however, do not cover programs concerning agricultural pollution control and urban domestic sewage treatment in counties with key ecological functions, the suggestion said.

It called on the central government to take conditions in Yunnan into full consideration and extend the coverage of the funding to such programs in the province.

Support is also needed in the province's efforts to cope with severe pollution in watercourses in urban areas during the flood season and in highland lakes, it added.