Shortage of clean water sources, continuous population growth, and unequal distribution of water resources are prompting many cities and countries to explore new supplementary water sources.
Limited water resource, Global population explosion, Extensive pollution
Global water consumption has increased six-fold during the 20th century, which is more than twice the rate of population growth. At present, about one-fifth of the world’s population lack access to safe drinking water. By 2025, it is estimated that about two-thirds of the world’s population will face moderate to severe water shortage problems. The rainwater collected locally can only meet 20-30% of Hong Kong’s fresh water demand. The remaining 70-80% of the water demand is provided by importation of Dongjiang water from Guangdong Province.
Facing the worldwide trend of water scarcity and the future increase in water demand in the rapid developing Pearl River Delta Area, for Hong Kong’s sustainable development, the HKSAR Government is implementing the (Total Water Management, TWM) programme to ensure rational utilisation, protection and management of water resources in a holistic manner and to explore new water resources.
Safe and usable water extracted from sewage in the treatment process is becoming increasingly important around the world. Most sewage is treated to a certain standard before discharge into receiving water body – usually a river or the sea. The treated effluent can undergo further treatment to become reclaimed water that would be clearer in appearance, and safe for reuse. The reclaimed water can be used for a wide range of applications in order to conserve water, e.g. cleansing roads and vehicles, parks and sports grounds irrigation, toilet flushing, fire fighting, industrial use, and landscaping.