Advancing on the promises of techno-ecological nature-based solutions: a framework for green technology in water supply and treatment

Nature-based solutions (NBS) are increasingly proposed for effectively and adaptively addressing societal challenges such as water security and natural disasters. However, NBS that are exclusively reliant on natural processes are not fit-for-purpose for the provision of safe drinking water – some range of built technology is required. There is a wide spectrum of techno-ecological NBS – ‘green technologies’ – that are fit-for-purpose in the treatment and distribution of safe drinking water. A framework was developed to enable an accurate and transparent description of the ‘green’ attributes of technology – including green infrastructure – in the water industry. The framework differentiates technology ‘greenness’ by relatively examining key attributes that may cause environmental impacts across the technology's life cycle through the lens of the environmental setting in which it is applied. In the water industry, green technology can be described by four main attributes: natural-resource basis, energy consumption, waste production, and footprint. These attributes are closely linked and must be considered relative to the biophysical and human environments in which they are applied and the other technologies to which they are being compared. The use of the framework can facilitate techno-ecological decision-making that strives to address diverse stakeholder priorities – including the influence of sociocultural factors on the green technology preferences of individuals, groups, or communities.