Application of constructed wetlands in recycling, agriculture and agroforestry: Water management for changing flow regimes

Abstract

Increasingly, constructed wetland systems are being utilized for treatment and buffering of effluent and runoff water, functioning in nutrient removal, disinfection and also as transitional environments in recycling applications. Agriculture and agroforestry opportunities are abundant for water treated by wetland systems. Progressively, wetland use as a component in potable recycling may be more acceptable in areas as changing flow regimes impact on water supply. This paper examines an innovative wetland application, the McGraths Hill Wetland Complex in the Hawkesbury District of NSW, Australia. The system has operated for more than a decade, founded on a concept to develop approximately 100 ha of land as an integrated reuse and wetland system with the objectives of (a) minimising effluent derived pollutants discharged to receiving waters and increasing water and nutrient reuse while meeting EPA requirements; (b) improving the visual amenity of the entrance to the local township through enhancement of the natural environment; (c) providing an economic return while reducing management costs; (d) providing and improving floodplain wetlands, receiving water riparian zones and other potential habitats; (e) providing a passive recreation resource and educational and research opportunities. The system is considered a success and, in addition to significantly reducing direct nutrient discharge to receiving waters, has produced of the order of 10,000 bales of lucerne hay (approximately 4200 T) per year and provided a woodlot resource. The integrated treatment complex is suggested as a key model for treatment train approaches to wastewater management. Changing flow regimes brought about by climate change and increased water abstraction are making multi-function, green technologies critical for community sustainability. © 2011 Springer Science+Business Media B.V.