The Mekong River Delta is under immense pressure. Upstream, a cascade of dams in China trap water and silt, the building blocks of delta life. Downstream, demand for irrigation water is rising in the world’s rice bowl.
A tough task for any country, managing the delta’s water problems come with an extra degree of difficulty for Cambodia and Vietnam — water use in one country influences water availability in the other.
The ties between the two countries, however, are not solely about surface water. The Mekong Delta sits atop a groundwater system that cross the political border. Pump too much here and water levels drop way over there, where the national flag is of a different stripe and color. The Mekong River declines too, because the aquifer is an underground drip feed to the river.