Adaptation through Water 2025

The first challenge – too much water – results from shifts in precipitation patterns. Excessive rainfall overwhelms rivers and storm surges threaten coastal areas. Globally, coastal and riverine areas are among the most severely affected, but urban areas are increasingly experiencing severe flooding. Southeast Asia is among the most vulnerable regions on earth to flooding of all types: coastal, riverine and urban. Viet Nam tops the at-risk list for both coastal flooding (ranked 2nd most at-risk worldwide) and riverine flooding (1st worldwide). Others at great risk of coastal flooding include the Philippines (7th) and Indonesia (13th). Those most at risk of riverine flooding include Thailand (4th), Cambodia (10th) and Indonesia (15th) – see Figure 3.2.2 Too much Very low flood risk Viet Nam is among the most exposed countries in the world to flood risk Very high flood risk Coastal, riverine and urban flooding risks facing Southeast Asia FIGURE 3 Sources: WWF Water Risk Filter, European Commission INFORM Risk Index, BCG analysis.9 In most coastal areas in Viet Nam, the Philippines and Indonesia, coastal defence solutions, such as breakwaters, seawalls and mangrove restorations, are already required in order to protect key economic zones from storm surge. Viet Nam, Thailand and Cambodia mandate the real-time monitoring of river levels, floodplain restoration and modular flood barriers to safeguard sensitive sectors along river basins. Major Southeast Asian cities require such flooding solutions as stormwater storage and advance drainage systems, given their proximity to coasts and rivers and their irregular precipitation patterns. Further fortifying the region’s adaptation and resilience to all types of flooding will take a total investment of roughly $13 billion between now and 2030 (see Figure 4 and Box 1). The Philippines, for example, requires the largest investment in coastal defence and resilience-building, given the country’s significant risk of coastal flooding from tropical cyclones. Thailand, Viet Nam, Indonesia and Malaysia deal primarily with riverine flooding and require hybrid infrastructure solutions. Fortifying the region’s adaptation and resilience to all types of flooding will take a total investment of roughly $13 billion between now and 2030. Adaptation through Water: Mobilizing the Private Sector for Climate Adaptation in Southeast Asia 9