Thanks to major efforts, the quality of the water in Baiyangdian Lake, Xiongan New Area, has reached record quality levels in recent years, a local environmental official said.

The reappearance of reed parrotbills at the lake, northern China's largest freshwater body, is evidence of that claim.

The parrotbill, an endangered species that lives in reed beds, had not been seen in the area around the lake for over a decade, according to Lu Hao, deputy Party chief of Santai township in Anxin, one of three counties covered by the new area.

"The birds are very sensitive to water quality and the environment, and they will leave if the water is polluted," Lu said in a speech made available by Xinhua News Agency.

Lu, who has worked at Xiongan for more than a year, is one of a number of graduates of Tsinghua and Peking universities recruited to participate in the construction of the new area.

One of his achievements is that he has changed some of the villagers' old habits. "People living near the lake used to dump domestic sewage and garbage directly into the water, which did great harm to the lake's ecosystem," he said.

A thorough clean up and ecological restoration of the lake was one of the first things done in the new area. Baiyangdian's environmental functions are being protected by a number of measures, including the containment of pollution from industrial and residential waste, and the replenishment of clean water.

Since 2018, nearly 2 million cubic meters of garbage have been removed from watercourses and areas around the lake, while more than 11,000 outlets that allowed sewage to enter the water have been eliminated, Cheng Gang, deputy head of the area's bureau of ecology and environment, said.

The measures have seen a fall in major pollutants, he added.

Last year, water replenishment projects transferred more than 300 million cu m of clean water to the lake, maintaining its depth at more than 6.5 meters and keeping the surface area at about 250 square kilometers, according to the bureau.

From last month to the end of June, about 60 million cu m of clean water will be fed into rivers downstream, which experts said will strengthen the lake's outflow system and improve its aquatic ecosystem.

Meanwhile, under a government plan detailing protection and restoration of the lake, the surface area is expected to be restored to 360 sq km by 2035 and the depth will be maintained at between 6.5 and 7 meters.