Nature-based alternative-water landscapes for water security and green space health

This paper is concerned with highlighting and learning from Alternative-Water Urban Landscapes (AWULs) from around the world. Such systems contribute to issues such as water security and greenspace health. Nature-based methods for treating alternative-water can provide for secure water supplies in local landscapes and a wide range of social and environmental co-benefits. However, such treatment methods have raised concerns about efficacy, safety, public opinion, and cost, which have often led to a reliance on centralised, and high-energy and chemical treatment methods. To move forward, more understanding about AWULs is required. The aim of this research is to reveal principles for the design of nature-based AWULs. A framework for the analysis of AWULs was developed from relevant literature works. The framework comprised two sets of criteria based on conservative and innovative aspirations for the AWUL design. A search of AWUL and landscape literature revealed 26 precedents as suitable. These were then analysed using the two sets of criteria which revealed three key outcomes. These included making use of free-water surface flow landscape-based treatment, large AWUL footprints and, partial decentralisation. These findings helped to fashion a set of design principles to guide and encourage adoption of nature-based AWUL by implementers.