Adaptation through Water 2025

Water challenges come in three forms: flood (too much), drought (too little) and pollution (too dirty). Other climate hazards are exacerbated by these challenges: larger amounts of water vapour in the atmosphere act as fuel for severe storms,6 while heatwaves and wildfires are related to drought.7 Southeast Asia is subject to all three types of water challenges. Several countries, such as the Philippines and Viet Nam, are prone to both coastal and riverine flooding, with Viet Nam more prone to riverine flood risk than any country in the world.8 Droughts in Thailand and Viet Nam caused more than $3 billion of losses in 2020, including reductions in agricultural outputs of between 30% and 45%. Poor quality water affects 100 million people or 15% of the region’s population, mainly in Indonesia and the Philippines. Addressing these challenges is a logical and effective starting point for climate adaptation. The term “adaptation through water” refers to promoting solutions that influence the natural or engineered water cycles to minimize the negative impacts of climate change. The engineered water cycle, which encompasses the managed supply, distribution, treatment and efficient use of water, has historically ignored the natural water cycle. This is no longer tenable, given the pressures on water supply from population growth, development, agriculture and industry. AtW calls for a change in the approach to climate- change adaptation: one that explicitly targets water cycles as the key to building resilience. The goals of AtW are as follows: –Preserve and harness nature’s power in regulating the water cycle. –Expand water infrastructure. –Cope with water scarcity by using water more efficiently and productively. –Prepare for a changing climate by planning for floods and droughts. –Improve water governance. –Scale-up financing. AtW entails action across all the major uses of water: agriculture, infrastructure, energy, industry and the environment (see Figure 2). Water’s role at the heart of adaptation benefits is nowhere more evident than in Southeast Asia. 2.1 Three water challenges – too much, too little, too dirty $3 billion losses from drought in Thailand and Viet Nam during 2020 100 million people: affected by poor water quality in Southeast Asia Riverine flood resilienceWater treatment & waste recovery Water use optimization Resilient food systems Water source diversification Water circularityMangroves, dykes & breakwatersUrban flood resilience Coastal defencesUrban water catchments Industrial water reuse/recyclingDrought- resistant cropsData-enabled forecasting Advanced irrigation Desalination plantsFloodplain wetlands & reforestationDams & reservoirs Rainwater harvestingWastewater treatment plants Adaptation through water (AtW): addressing climate impacts through natural and engineered water cyclesFIGURE 2 Source: BCG analysis.