Water cooperation is essential when countries share lakes and rivers – yet it’s been deteriorating in many places, with serious consequences

Lake Chad once provided adequate livelihoods for 20 million people in Africa, but it lost 90% of its surface area in 30 years. AP Photo/Christophe Ena

Just over half the world’s population shares a river or lake basin with at least one other country. To sustainably manage those water resources for the health of people, ecosystems and economies, neighboring countries must work together.

However, many countries have been less willing to cooperate in recent years, even to protect a resource as vital as freshwater.