Nearly two years after the South-to-North Water Diversion Middle Route began carrying water, what has 5 billion cubic meters of southern water brought?

Since the first phase of the South-to-North Water Diversion Middle Route Project began carrying water, more than 600 days have passed, with 5 billion cubic meters of water diverted, benefiting more than 40 million residents in Beijing, Tianjin, Hebei and Henan. Sharing the same river water, 30 representatives from the water source area of the middle route recently visited Beijing and Tianjin to discuss "water diversion, water use and water conservation" with people in the receiving areas and experts.

Nearly two years after water began flowing, what has the South-to-North Water Diversion brought to the areas along the route?

Water quality has improved, and the security of water supply is better guaranteed

"The water is good now!" In the Lanshuiyuan residential community in Hexi District, Tianjin, Aunt Cui Xiufang told the representatives: "Tianjin used to have a strange saying - tap water so salty it could pickle vegetables. The water I drank as a child was bitter and astringent, and you couldn't even brew tea with it."

"There's much less scale now!" Liu Suxiang, a resident of Jianxinyuan Sili in Fengtai District, Beijing, brought out her kettle to prove the point: "Look, this kettle hasn't been scrubbed for a month, and there's hardly any scale."

Southern water quenches the "thirst", and the most direct feeling for people in the receiving areas is that the water quality is better and there is less scale. Data show that the water quality of the Danjiangkou Reservoir at the source has remained stable at Class II for many consecutive years. According to monitoring by the Beijing Waterworks Group, after the use of southern water, the hardness of tap water dropped from 380 milligrams per liter to 120-130 milligrams. "Danjiang water has low hardness and is slightly alkaline, so it tastes better than groundwater." Technical staff at the Guogongzhuang Water Plant explained.

The water supply pattern is also changing. "Beijing has thus bid farewell to its dilemma of relying on a single water source, and the water supply security coefficient in the central urban area has risen from 1.0 to 1.2." Sun Guosheng, director of the Beijing Office of the South-to-North Water Diversion Project, explained that more than 70% of the water supply in the urban area now uses southern water, directly benefiting 11 million residents.

By 2020, Beijing will achieve "joint regulation of three water sources" - the Miyun Reservoir, groundwater sources and external diverted water. Southern water will mainly be used for urban domestic purposes, supplying 20 water plants in the central city and new towns. The supply area will basically cover the Beijing plain area, benefiting 20 million people.

Liu Changping, deputy inspector of the Tianjin Water Affairs Bureau, said that as of now, Tianjin has added 1.06 billion cubic meters of water, and more than half of urban residents are drinking southern water. The city has moved from "a single Luan River diversion" to "dual-source security", equivalent to adding another lifeline for water transmission, effectively resolving the contradictions of "dependence, singularity and vulnerability" in urban water supply.

Water use has become more economical, with water conservation given priority rather than "doing whatever one likes"

Southern water has not come easily, and the receiving areas insist on prioritizing water conservation, not using water "however they please".

Sun Guosheng explained that Beijing acts according to its water quantity and adheres to the principle of "drink, store, replenish". Of the 1.58 billion cubic meters of southern water diverted, "drinking" is satisfied first, with 70% supplied to water plants for urban domestic use; then comes "storage", with 200 million cubic meters currently stored in the Miyun Reservoir, Huairou Reservoir, Shisanling Reservoir and Daning Regulating Reservoir, playing an important role in Beijing's water resource allocation; and also "replenishment", carrying out groundwater recharge.

Beijing strictly manages water and tightens the "tap", replacing 78,000 sets of high-efficiency water-saving fixtures across the city last year. It makes greater use of reclaimed water - more than 70% of river and lake replenishment in Beijing comes from reclaimed water, and last year reclaimed water accounted for one quarter of total water use, becoming a stable "second water source". During the "12th Five-Year Plan" period, Beijing saved an average of 100 million cubic meters of water per year, equivalent to saving one large reservoir each year.

Tianjin carefully calculates every drop, dividing water into 5 types: surface water, groundwater, external diverted water, reclaimed water and desalinated seawater, achieving differentiated pricing and using the best water for the best purposes. The reuse rate of industrial water has reached 92%, and the utilization rate of reclaimed water has reached more than 30%.

Water conservation is becoming a consensus. In the water-saving communities in the receiving areas, rice-washing water is first used to wash vegetables and then to water flowers, and laundry water is used to flush toilets. "Using water multiple times" has become a daily habit for many residents. Tianjin has built 1,056 water-saving enterprises and 476 water-saving communities, with coverage rates reaching 44.9% and 18.2% respectively. Beijing has built 1,178 rainwater and flood utilization projects, and last year the comprehensive utilization of urban rainwater reached 162 million cubic meters.

Ecology has benefited, and groundwater levels are gradually recovering

With surface water available and groundwater strictly controlled, ecological benefits are gradually emerging. Thanks to the replenishment from southern water, Beijing has reduced groundwater extraction by 114 million cubic meters. At the same time, it carried out trial replenishment of 84 million cubic meters to the water source areas of Miyun, Huairou and Shunyi, significantly raising the regional groundwater level, with the largest local rise reaching 8 m. Monitoring shows that at the end of July this year, the average depth to groundwater in the Beijing plain area had recovered by 62 cm compared with the same period last year.

To make up for ecological deficits, Beijing used southern water to replenish 174 million cubic meters to urban rivers and lakes. Through joint regulation with existing reclaimed water, the urban water ecological environment has been improved, with water quality approaching Class III surface water. The once-dry Lugou Xiaoyue Lake has once again shimmered with rippling light. Aunt Xu, an 83-year-old resident, said with emotion: "I never imagined I could see the scene from 20 years ago again."

Tianjin has redrawn the prohibited and restricted groundwater extraction zones, proposing that by the end of 2020, the city's annual extraction of deep groundwater be kept within 90 million cubic meters. Over the past two years, more than 80 water-using units have completed source conversion, reducing permitted groundwater extraction by 10.1 million cubic meters and backfilling more than 110 motor-pumped wells.

Dong Shulong, director of the Comprehensive Affairs Division of the Tianjin Office of the South-to-North Water Diversion Project, said that Tianjin has turned ecological emergency water replenishment into regular replenishment, with a cumulative 520 million cubic meters replenished to landscape rivers, providing strong support for the building of "Beautiful Tianjin".

"As South-to-North Water Diversion water supply becomes routine and groundwater extraction reduction targets are gradually achieved, Tianjin's groundwater level will gradually recover." Dong Shulong said.