More water, move, clear
Baiyangdian’s “kidney of North China” function is recovering
According to statistics, since 2018, Hebei Province has replenished 1.304 billion cubic meters of water for Baiyang Lake, with an average annual inflow of 430 million cubic meters, keeping the water level of Baiyang Lake stable above 6.5 meters. In the past two years, the highest water level in Baiyangdian reached 7.4 meters, which is a rare high water level in the past 20 years.
The Baiyangdian Tanghe Lake Inlet Wetland is the area where the Tanghe River and Baiyangdian Lake intersect. Due to the decrease of water from upstream and the continuous increase of industrial and agricultural water consumption, the natural lake mouth has been artificially changed into farmland, dry land, etc., and the wetland ecosystem has been seriously degraded. Through measures such as returning farmland to wet land, restoring the natural water system form and diversifying the biological habitat of the wetland, the wetland at the entrance of the Tanghe River is now covered with green grass, rippling blue waves, and the lake gulls and egrets inhabit in a leisurely manner. The beautiful scenery of “Taitian reed sea and bird paradise” is gradually reappearing.
The restoration of Tanghe Lake Inlet Wetland is the epitome of the whole Baiyangdian Lake ecological environment governance. The report of the State Council on the ecological protection of Xiong’an New Area and Baiyangdian Lake shows that the phased objectives specified in the Baiyangdian Lake Ecological Environment Governance and Protection Plan (2018-2035) have been basically achieved. The overall water quality of the lake area has been upgraded from inferior Class V in 2017 to Class IV in 2020, and the average water quality of the lake area has reached the Class III standard. In the first half of this year, the water quality of the four major rivers entering Baiyangdian Lake and the 50 river sections in the upper reaches of the river basin all reached or exceeded Class IV, the best level in the past 10 years.
Ecological water supplement and reasonable regulation of lake and lake hydrology and water resources
Baiyangdian Lake is the largest freshwater lake in North China. There are 143 lakes and more than 3700 ditches crisscrossing the 360 square kilometers lake area. As a rare natural wetland in northern China, Baiyangdian Lake is known as the “kidney of North China” and plays an irreplaceable role in maintaining the ecological environment in North China.
However, since the 1950s, the dry climate, the continuous increase of industrial and agricultural water consumption, and the continuous construction of upstream reservoirs have led to a continuous decrease in the amount of water entering Baiyangdian Lake. At the same time, the upstream water and soil loss and the reclamation of farmland within the lake have accelerated the sedimentation of Baiyang Lake and the water surface of the lake area is shrinking.
In addition, the discharge of urban domestic sewage and industrial sewage, and aquaculture in cages have led to the continuous deterioration of the water quality of Baiyangdian Lake. A villager near the Lake District said that during the period of the most serious pollution, “even birds did not fly”.
On April 1, 2017, Xiong’an New Area was established, and the battle of Baiyangdian ecological environment governance and protection was launched simultaneously. Baiyangdian is located at the “bottom of the nine rivers”, so the battle against difficulties requires comprehensive treatment from the perspective of “a game of chess” in the whole basin.
Ask the canal to be clear so that there is a source of fresh water. Lack of fresh water supply and sharp decrease of ecological flow are important threats to the ecological environment of Baiyangdian Lake. The most direct and effective measures to restore the Baiyang Lake ecosystem are to implement ecological water replenishment and reasonably control the lake’s hydrological and water resources.
According to statistics, since 2018, Hebei Province has replenished 1.304 billion cubic meters of water for Baiyang Lake, with an average annual inflow of 430 million cubic meters, keeping the water level of Baiyang Lake stable above 6.5 meters. In the past two years, the highest water level in Baiyangdian reached 7.4 meters, which is a rare high water level in the past 20 years. In particular, Baoding City, located at the upper reaches of Baiyangdian Lake, has scientifically allocated water resources and implemented ecological water replenishment for rivers entering the lake. Among them, Fuhe River, Xiaoyi River, Baohe River, Baigou River and other rivers basically have water flowing into the lake all the year round, making Baiyangdian Lake better restored.
According to the 2021 Baiyangdian Ecological Water Replenishment Work Plan of Xiong’an New District, Hebei Province, the planned ecological water replenishment this year is about 400 million cubic meters. Xiong’an New Area has also established and implemented an ecological water replenishment operation mechanism. According to the ecological water demand of Baiyangdian Lake, it scientifically adjusted the water replenishment period, water source and quantity, and increased the hydrodynamic force and water body mobility.
Systematic governance to build a sustainable wetland ecosystem
In addition to ecological water replenishment, He Lifeng, director of the National Development and Reform Commission, also said that the pollution prevention and control of the Daqing River basin and Baiyangdian Lake were comprehensively promoted, and the systematic governance of “source control – pollution interception – river control” was implemented, and the “kidney of North China” function of Baiyangdian Lake was steadily restored.
“The Baiyangdian Tanghe Lake Inlet Wetland Ecological Protection Project, which has been implemented since 2018, is a typical case of comprehensive treatment. We adopt a natural-based solution, take the principle of minimum human intervention, respect nature, reduce the possibility of damaging the environment, fully combine the current conditions of the site, environment, climate and other factors, and try to reduce the interference to the natural environment from the starting point of protection and restoration.” Said Min Ying, executive president of the design group of Beijing Zhenghe Hengji Waterfront Ecological Environment Management Co., Ltd.
At the junction of the wetland and surrounding villages, green dikes become ecological buffer zones to intercept domestic sewage and agricultural non-point source pollution from surrounding villages and towns. The project team will reshape the ecosystem according to the spatial landform of the wetland, form an ecological corridor with blue and green interlaced, optimize the flow path of the Tanghe River after entering the lake, and increase the hydraulic retention time. According to the functional zoning and landscape requirements of the wetland, the project team selects and matches reed and other plant populations to improve the absorption of nutrient-rich substances by plants in the water body and achieve the goal of water purification.
“We hope to build the Tanghe Lake Entrance Area into a wetland ecosystem restoration demonstration area that is close to nature, low impact and sustainable development, and become a model for the organic integration of regional natural ecology and human ecology and high-quality development,” said Min Ying.
The water in Baiyangdian Lake has become clear, the water surface has become larger, and the wetland ecosystem and the “kidney of North China” function are gradually recovering. According to the data, when the Baiyangdian Wetland Reserve was established in 2002, 192 species of wild birds were recorded. In recent years, by increasing the ecological protection of Baiyangdian Lake, the number of wild birds has increased, and the species record has increased to 230. During the observation from the winter of 2020 to the spring of 2021, 48 Great Bustards were recorded as the national key protected birds. In order to protect the biodiversity of aquatic organisms in Baiyangdian Lake, Hebei has set up a scientific fishing ban in Baiyangdian Lake, with the cumulative proliferation and release of more than 150 million aquatic species, and the species of bitterling, black fish, and gafish that have not been seen in Baiyangdian Lake for many years have reappeared.
“Perch that has not been seen for more than 30 years now reappears in Baiyangdian.” Zhang Fuqing, a cadre of Xiaozhangzhuang Village in Anxin County, lived near Baiyangdian since childhood. He said that perch has high requirements for water quality, and its reappearance also proves that the water quality of Baiyangdian has improved.
Control source and intercept sewage to prevent a drop of sewage from flowing into Baiyangdian Lake
Zhao Xianwei, director of the Water Ecological Environment Division of the Department of Ecological Environment of Hebei Province, said that the Baiyangdian Lake treatment will also focus on the domestic pollution of the original villages, the accumulated pollution of the sediment in the lake area, and the secondary pollution of tourism and shipping, implement a series of powerful measures and carry out exploratory practice.
The domestic sewage and garbage from the original villages are also important sources of pollution in Baiyangdian Lake. According to the statistics of the former Environmental Protection Bureau of Baoding City, the nitrogen and phosphorus input of Diannei Village accounted for 1/4 and 1/3 of the total nitrogen and phosphorus input of the basin respectively.
While rapidly promoting the construction of Xiong’an, Hebei has also strengthened the protection of Baiyangdian, the only water body in Xiong’an New Area, and put forward the slogan of “not letting a drop of sewage flow into Baiyangdian”. In addition, according to the requirements of Hebei Province “to ensure that the water quality of the lake area will reach Class IV and strive to reach Class III in part by 2021”, according to the discharge standards of conventional sewage treatment plants, the water quality of the effluent cannot meet the requirements for entering the lake. Therefore, in the past, the domestic sewage in the villages in Baiyangdian City was in the form of “reverse drainage”, that is, the sewage was transported to the sewage treatment plant in the peripheral towns for centralized treatment. This is not only costly, but also prone to problems such as “leakage”.
Now in Baiyangdian Chengzhong Village, the domestic sewage from the villagers’ homes flows into the deep denitrification equipment through the pipe network, and the treated water flows into small ponds and other water bodies for re purification… This is the demonstration project of deep denitrification of sewage in Baiyangdian Chengzhong Village participated by the Ecological Center of the Chinese Academy of Sciences and Beijing Zhongchi Bize Environmental Technology Co., Ltd. As the advanced treatment unit, the nitrogen removal technology jointly developed by both parties plays an important role in the deep removal of nitrogen and phosphorus.
“After secondary biochemical treatment, the sewage can meet the Class IV surface water standard except for nitrogen and phosphorus indicators. Then, nitrogen and phosphorus technology is used to strengthen the treatment of nitrogen and phosphorus, and the total nitrogen concentration in the water is basically controlled below 1.5 mg per liter. Then, through the deep purification of downstream constructed wetlands and natural wetlands, the ultra clean discharge of sewage is finally achieved.” Dr. Sun Yilu, from the Ecological Environment Research Center of the Chinese Academy of Sciences, said, As the rural sewage project with the highest discharge standard at present, the sewage after deep denitrification treatment meets the discharge requirements of the lake, and also plays the role of ecological water supplement for Baiyangdian Lake.
“Baiyangdian Lake’s ecological environment governance is not only the governance of Baiyangdian Lake, but also the governance of the entire basin.” Gao Yinghua, director of the Bureau of Ecological Environment of Xiong’an New Area, said that the basin’s ecological environment governance is a systematic governance. Next, “we should promote the governance and protection of the entire basin, including upstream and downstream, left and right banks, inside and outside the lake”.