Use of Recycled Water for Irrigation of Open Spaces: Benefits and Risks

Abstract

The supply and sustainable use of recycled water may play an important role in enhancing urban water supplies in many water-scarce parts of industrialised countries like Australia because of the reduced treatment cost relative to seawater desalination and imported surface water. One such reuse option includes application of recycled water in the irrigation of urban open spaces. In 2009–2010, in Australia, the state-wide average of recycled water use in urban irrigation was 27.2 % and the nation-wide average was 14 % of the total recycled water produced. In Sydney, New South Wales (NSW) approximately 3.8 GL of recycled water is used for irrigating sports fields, golf courses, parks, landscapes and racecourses and, by 2015, it is expected that the recycled water will meet 12 % of the total water demand in greater Sydney. Despite significant benefits of recycled water, there are several concerns related to environmental and health risks. If not properly managed, recycled water could deteriorate soil health in terms of increased salinity and sodicity, heavy metal accumulation and decreased hydraulic conductivity of soil. However, there are tools to reduce risks due to urban irrigation using recycled water; such as, national and state-wide standards of recycled water quality for urban irrigation, sustainable urban water management strategy and the pollutant control framework. In this chapter, recycled water usage for urban open space irrigation was discussed in the international and national contexts. Also, benefits and risks associated with recycled water usage in open space irrigation were examined and possible control measures were discussed.