Located in China’s east coast, Qingdao faces chronic water shortage, where per capita water resources are only 12% of the national average. Qingdao with more than 5 million inhabitants suffers from an acute water shortage. Its water resources are unevenly distributed, both temporally (inter-annual and intra-annual variations are large) and spatially (the urban center, which has the highest population density and the highest development density, is the area which has the worst water shortages). It is characterized by having relatively plenty of water for a short period of time, and then followed by prolonged drought.
Since the energy intensity of producing water from desalination, reclaimed water or long-distance water diversion is much higher than that for supplying water from conventional sources, Qingdao must work out how to allocate its various water sources, so it can ensure the security of its water supply while also reducing the urban water supply’s carbon emissions. In order to meet its growing water demand, long-distance water transfer or the exploitation of unconventional water resources (such as desalination and reclaimed water) are already seen as a necessary step for to supply water for the city.
With financial support from the Caterpillar Foundation and the UKFCO Strategic Prosperity Fund, and the help of Qingdao’s Development and Reform Commission, the Qingdao Water Supply Division, and the Qingdao Municipal Water Conservancy Bureau formed an international research team of specialists to help Qingdao analyze and find a water-energy resource balance for its urban water allocation mix. Multi-pronged approach has been used to identify the water supply potential and the advantages and disadvantages of using various types of water sources by analyzing Qingdao’s naturally-occurring water resources, predictions of the future trends in water use, potential energy consumption of the urban water system, and then developing scenario analyses of the energy demand of the urban water supply system in 2020. This has provided a number of options for Qingdao’s principal future exploitable water sources. These are: local surface water, local groundwater, water diversion from the Yellow River/Yangtze River, seawater desalination and reclaimed wastewater.
Outcomes and lessons learnt
- Qingdao’s urban water system faces an inevitable rise in energy intensity and carbon emissions. It will need to incorporate carbon accounting and energy management into its water supply planning to help it reduce the urban water system’s carbon footprint allowing it to pursue low-carbon sustainable development.
- Qingdao does not only need to consider factors such as cost and continuity of supply when deciding on a water source allocation mix, it also needs to thoroughly consider the type of water source, energy consumption for unit water supply, carbon emissions, and environmental risks.
- Of all the unconventional sources of water, reclaimed water is the best in terms of carbon emissions and cost. High-grade reclaimed water (NEWater) is not only relatively secure in terms of supply, but compared to other unconventional water sources, its carbon intensity and cost of production is also lower.
Photo: Qingdao City, by Mgmoscatello (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons - photo has been cropped but not otherwise altered