*3.4. Vietnam*

Effective water resource managemen<sup>t</sup> plays a crucial role in Vietnam's economic development, with 80% of its GDP generated in its key river basins [116]. Despite having, on average, about 2000 mm rainfall per year and about 3500 rivers in 16 major river basins, water availability is highly seasonal and unevenly distributed across the country [117]. In turn, this contributes to severe water scarcity in some regions at particular times of the year [118].

Vietnam has over 90 million people and is rapidly industrializing and urbanizing, which is contributing to greater extractions of both surface and groundwater [116,117]. Consequently, stark trade-offs are emerging in water allocation for agriculture, industry, and households. Further, about two-thirds of Vietnam's water resources are sourced beyond its borders, such that its internal water resource availability is 4200 m<sup>3</sup> per person compared to an average of 4900 m<sup>3</sup> for South East Asia [119].

The supply of water is affected by water pollution with only 12% of domestic wastewater [120] and 25% of industrial wastewater treated before being discharged into streams and rivers [121]. As a result, untreated wastewater has polluted rivers and lakes in and around big cities and industrial zones, undermining the health and livelihoods of millions of people [116,117,119].

Water scarcity and pollution are being exacerbated by climate change. It is estimated that a sea level rise of one meter by the end of this century will displace about 11% of the population, mainly in the Red River Delta and the Mekong River Delta and along 3000 km of the coast [122]. Recent severe typhoons and storm surges, as well as other extreme weather events, such as drought and flash floods, have cost around US\$1.75 billion [118] and are projected to be a major challenge in the future in the Mekong Delta that produces half of Vietnam's rice [116,118].
