Informal settlements ('slums') are home to more than a billion people, mostly in rapidly growing urban areas of low- to middle-income countries. They have poor health and wellbeing, inextricably linked to environmental exposure to pathogens, pollutants, and disease vectors in water, food, air, and soil. But what are the solutions? The conventional ‘big pipes’ approach to water provision and sanitation has changed little in 150 years; it relies on large, centralised, energy-intensive infrastructure to provide, capture, treat, and dispose of water and human waste. From health, social, and ecological perspectives, this is failing to meet the challenges of (i) rapid population growth and urbanisation, (ii) limited water resources and environmental capacity to assimilate anthropogenic pollution, and (iii) the impacts of climate change. Also standing in the way of equitable water provision are the interrelated challenges of high government debt, informal settlement poverty, and a pervasive lack of financial transparency.
Our vision is to improve human, environmental, and ecological health in informal urban settlements across the developing world through a new approach to the provision and use of water. We will design an accelerated water-sensitive revitalisation approach across 24 informal settlements in Makassar, Indonesia, and Suva, Fiji. We have pioneered an alternative approach to water services delivery in the relatively developed economies of Australia, Singapore, China, and Israel. The water-sensitive approach integrates ecologically and economically sustainable water infrastructure (also known as ‘nature-based solutions’) into buildings and landscapes. Decentralised water infrastructure is implemented at dwelling, neighbourhood, and precinct scales to harvest rainwater/stormwater, recycle wastewater, and protect against flooding and environmental pollution. Wastewater is managed locally using natural passive treatment processes such as constructed wetlands and natural filters. Stormwater runoff is conveyed to minimise flooding and environmental pollution, using grassed channels, surface wetlands and biofiltration gardens. Locally sourced water is used for a range of domestic purposes and economic activities including urban agriculture, while greenspaces increase local amenity.
We will incorporate greenspaces as a co-benefit to infection control, to enhance local amenity and create opportunities for microeconomic activities (e.g. urban food production) using locally sourced water. Doing so will enhance communities’ resilience to the effects of climate change (droughts, floods, heatwaves) by diversifying water resources and improving stormwater and floodwater drainage. These benefits can only be delivered through an approach integrating several green, water-servicing infrastructures and activities. Our project leverages a co-investment by the Asian Development Bank (ADB) who will finance the decentralised water infrastructure to enable the provision of water, sanitation, flood protection, and environmental stewardship. The project will provide an evidence-based assessment of the efficacy of the water-sensitive approach in revitalising settlements poorly served by water infrastructure in the Asia-Pacific. A critical component of success and sustainability of the approach will be working in partnership with communities and other stakeholders to establish a roadmap for urgently needed access to essential water services and greater resilience to the effects of climate change now and into the future.