Kala Oya River Basin: Where small irrigation tanks are not really small

This case study describes an exercise that was undertaken in the Kala Oya Basin of Sri Lanka to assess the livelihood and biodiversity values of traditional tank systems. The Kala Oya Basin has been identified by the government as the pilot river basin to plan and implement integrated river basin management approaches in Sri Lanka. By articulating tank values, the study had a particular focus on integrating downstream wetland values into upstream land use and water allocation decisions, and showing that upper catchment conservation and water allocation to traditional tank systems can yield high, and quantifiable, economic returns.