IWMI: Sri Lanka needs water-aware climate governance after Cyclone Ditwah
An analysis by the International Water Management Institute says Sri Lanka’s Mahaweli River planning can no longer rely on historical patterns after Cyclone Ditwah. The cyclone caused an estimated $4.1 billion in direct physical damage, exposing the limits of existing approaches. IWMI argues that the water cycle should be treated as an active part of climate risk and that governance must adapt to more intense floods and droughts.
IWMI's review uses the Mahaweli, Sri Lanka's longest river, to show how planning tied to past conditions becomes unreliable. The river supports hydropower, rice cultivation, and flows to the sea, but Cyclone Ditwah's roughly $4.1 billion in direct damage illustrates risks beyond historical norms.
The institute says warming can intensify moisture extremes, making some wet periods wetter and dry spells drier. It also notes governance gaps: soil and vegetation moisture receive less attention than rivers and reservoirs, while groundwater monitoring remains limited, especially in smaller aquifers and parts of Central Asia and sub-Saharan Africa.
The findings may prompt Sri Lankan policymakers, farmers, hydropower operators, and urban water users to reconsider assumptions about river flows and storage. If governance remains tied to historical patterns, communities could face greater uncertainty during floods or droughts. A shift toward water-aware planning may affect how irrigation, groundwater, and reservoir decisions are made, with consequences for food production, energy reliability, and household water security.