Over a thousand hectares of farmland will be converted to wetlands to help purify water at Baiyangdian Lake, northern China's largest freshwater wetland, in Xiongan New Area, Hebei province.

Baiyangdian Lake, made up of 143 small lakes divided by wetlands and covering 366 square kilometers, is known as the "kidney" of North China, as it has the dual functions of repairing ecology and improving the environment.

Among various measures taken for the lake's restoration, Xiongan launched a project in July to restore two functional wetlands at mouths of two upstream rivers - Fuhe and Xiaoyihe rivers - by converting the area's farmlands to wetlands.

The project is expected to be finished next year, according to China Xiongan Group Ecological Construction Co, which is in charge of it.

The restored wetlands will be used for purifying water coming from upstream rivers through sewage degradation, said Peng Zhanqi, manager of water environmental projects with the company.

They are two major rivers whose water runs into Baiyangdian, but a big portion of that water was raw sewage or tailwater from sewage treatment plants at upstream areas, making them major sources of pollution, Peng said.

The restored wetlands can purify a water volume of 450,000 cubic meters each day, equivalent to a day's sewage discharge in a medium-sized city, Peng said, adding the water quality into Baiyangdian will be greatly improved.

Next year, another 6,000 hectares of farmland will be transformed into wetlands at Baiyangdian.

Other projects, including water replenishing and stopping sewage drainage from industrial and residential sources, are underway to restore the ecosystem of Baiyangdian.