Shuanggui Lake in Liangping District is the second-largest freshwater lake in Chongqing, with 349.97 hectares. In the past, the water quality of Shuanggui Lake was inferior, below Class V, owing to the silt deposition and eutrophication caused by fertile fish farming.

Shuanggui Lake before restoration (Photo provided to iChongqing)

In recent years, Liangping District has taken the protection of the source as the foundation, treatment, purification, and protection, and other serious measures to ensure the water quality safety of Shuanggui Lake. For example, a 13-kilometer rain and sewage pipe network has been set up around Shuanggui Lake to divert rain and sewage and prevent seeping into the lake. Organic, ecological planting is also encouraged, where pesticides and fertilizers are not applied to reduce the lake’s nitrogen and phosphorus pollution and nutrient enrichment.

On this basis, Liangping District focuses on the ecological restoration of small and micro wetlands around the lake. With the help of ecological barriers such as biological ditches, rain gardens, habitat ponds, and cascade small and micro wetlands, the rainwater is purified layer by layer to ensure the lake’s water quality reaches the standard.

Shuanggui Lake after restoration (Photo provided to iChongqing)

Today, the water quality of Shuanggui Lake has been stable above Class III all year round, providing suitable habitats for wild animals.

For Class III water supplies in which high-level maintenance can be expected, the limit is around 2500 to 5000 MPN per 100 ml. For bathing, 1000 MPN per 100 ml was established as the standard.

The biodiversity of Shuanggui Lake National Wetland Park has increased significantly. Tourists also long for the 623 plant varieties and 277 species of vertebrates  (including 207 birds) that inhabit Shuanggui Lake, where the blue-headed pochard, grey geese, and other rare endangered birdlife love to nest.