Construction of Backup Water Sources

　　 Reasonably plan the locations of backup water-source intake points and water treatment plants, leverage natural gradients to enable gravity-fed conveyance of raw and treated water, minimize the use of pressurized pumping equipment and facilities, reduce energy and material consumption, and conserve resources. As a backup water-source project, it is imperative to strengthen protection of the water-source area by delineating protection zones, establishing regulations that restrict development activities, and putting in place a comprehensive pollution prevention and control system.

　　 To improve the vulnerability of urban water supply security, it is necessary to move away from a single-source supply model and establish a networked system integrating multiple water sources.

　　The development of backup water sources involves numerous aspects, including overall planning and design, the relocation of residents and polluting enterprises, and the delineation of source protection zones, all of which require substantial human, material, and financial resources.

　　While accelerating the development of backup water sources, we must also remain vigilant in protecting existing water sources, so as to better ensure the city’s drinking water safety.

　　To address the vulnerability of urban water supply security, in addition to safeguarding water sources, maintaining and managing the distribution network, and enhancing service quality, it is essential to move away from the single-source supply model that relies on a single watershed, reservoir, or river channel and instead establish an interconnected multi-source water supply system.

　　With regard to policy requirements for the development of backup water sources, the “National Plan for Ensuring Urban Drinking Water Safety (2006–2020)” stipulates that priority should be given to the renovation and expansion of existing water sources, while simultaneously pursuing both capacity enhancement through upgrading and the development of new water sources, in order to build urban drinking water source projects.

　　In recent years, China has steadily accelerated the development of backup water sources. In 2010, among the country’s 314 cities at or above the prefecture level, only 216 had established backup water supplies; this number rose to 231 in 2011 and further to 248 in 2012. Wuxi, which once suffered severely from the Taihu Lake algal bloom incident, has taken the lead in establishing a “dual-source supply—Taihu Lake and the Yangtze River—interconnected pipeline network, providing double redundancy” system. Chongqing has also developed a “two-river mutual support” configuration, with water supplied from both the Jialing River and the Yangtze River. Beijing’s water supply portfolio is even more diversified, drawing on surface water from reservoirs such as Miyun Reservoir as well as deep groundwater, and this year will additionally receive “South-to-North Water Diversion” water from the south.

　　Even with risk-prevention awareness, identifying backup water sources that offer good water quality, sufficient supply, and convenient proximity is no easy task. This is precisely the main reason why the establishment of urban backup water-supply sources has been so slow. It is encouraging to note that, in recent years, China’s water-environment quality has steadily improved and protection efforts for drinking-water source areas have been continuously strengthened; nevertheless, there are still instances where the quantity and quality of water at existing source areas have declined. This makes the search for high-quality backup sources even more challenging. “Some existing source areas have been abandoned because their water quality fails to meet standards—for example, due to climate change, Zhongshan in Guangdong Province is seeing increased chloride levels in its water sources and is now actively seeking new ones,” said Wang Hao.

　　Even when high-quality water that meets standards is identified, establishing backup water sources is no easy task. Excessive distances drive up construction investment and make maintenance and management significantly more challenging. For a city, developing backup water supplies entails comprehensive planning and design, the relocation of residents and polluting enterprises, the designation of water-source protection zones, and numerous other considerations—requiring substantial human, material, and financial resources.

　　Some undeveloped water sources located relatively close to urban areas have, due to factors such as land value appreciation, been successively converted into urban construction land, thereby necessitating the search for water sources in more remote locations. To protect water quality, the use of chemical fertilizers and pesticides, as well as the establishment of livestock farms and mining operations, is typically prohibited in the vicinity of water sources, which results in slower economic development in the surrounding areas. Consequently, ecological compensation must be provided to local residents, and the associated costs should not be overlooked.

　　At present, it is imperative both to accelerate the development of alternative water sources and to maintain stringent protection of existing water sources, so as to better ensure the city’s drinking-water safety.

　　In recent years, China’s water environmental quality has been steadily improving; however, the situation regarding source-water protection remains extremely challenging. Strengthening source-water protection requires particular emphasis on preventing non-point source pollution by minimizing the use of chemical fertilizers and pesticides and keeping such areas away from major pollution sources such as landfills and chemical plants. For river-based source waters, it is essential to ensure the cleanliness of upstream inflows and to coordinate pollution control efforts between upstream and downstream sections. In cities that rely on groundwater as their primary water source, domestic water supply should prioritize groundwater, while industrial and agricultural water use should, wherever possible, make greater use of surface water.

None

Industrial Park Wastewater Treatment

None

Industrial Park Wastewater Treatment

Related Cases