Design process of a water reclamation garden: from natural niches to urban environment

Abstract

Water reclamation gardens have existed for more than 20 years, combining wastewater process technology and botany to provide wastewater treatment. In these facilities, the boundary between functional gardening and sanitation/water reuse infrastructure is blurred. They use lower footprints than engineered wetlands and can be constructed in urban areas as they do not look or smell like conventional industrial facilities, while providing water treatment on the same scale. These gardens produce treated wastewater, while at the same time provide green and blue access to the community. Treatment can be more effective and adaptive using decentralized systems, where facilities are closer to the waste origin, in this case municipal areas, thereby minimizing costly infrastructure (piping network). For this to work, the treatment units must gain far more public acceptance, and a well-designed and functioning water reclamation garden helps this purpose greatly.There are three main considerations in designing garden facilities; one is climate. It is necessary to determine whether the local climate can support a reclamation garden or whether an artificial microclimate is needed. The species arrangement is primarily defined by the wastewater treatment process. Plants rooted in the wastewater encounter different environments as the treatment process advances. This phenomenon further delimits available species. Selection is based on equivalence of the original plant habitat to the designed treatment phase and conditions. Considering the needs of the community, the local garden and architectural style defines what a community sees as acceptable or pleasing, sometimes even on a subconscious level. Knowledge of the local gardening trends and cultures helps creating gardens which will then be an integral part of a city’s urban fabric.Based on the aspects described above, a methodology for a three-layered comparative design practice is introduced, linking wastewater process knowledge, ecological knowledge and information on stylistic trends. Utilizing these tools provides a solid foundation to answer all these demands and builds a foundation for long-term sustainability.