Adaptation to climate variability in sri lanka: A case study of the huruluwewa irrigation system in the dry zone

Abstract

This paper assesses how the Huruluwewa tank (HWT) irrigation system in the North Central Province of Sri Lanka adapts to climate variability. Irrigation systems contribute to more than 90% of the staple food production in Sri Lanka. It is a country that bears one of the highest climate risks in the world. Further, in the North Central Province, recurrent droughts are the bane of agriculture. In the HWT, the fifteenth largest canal irrigation system in the country, adaptation to climate variability happens on two fronts: changes made by the irrigation management to the water release regime; and changes in the cropping patterns practiced by farmers in the command area. Such adaptation measures ensure that the available water supply in the reservoir is adequate for 100% cropping intensity in each of the two cropping seasons, which, when combined with diversification of cropping patterns, enhances economic water productivity in terms of value per unit of consumptive water use. Such cropping patterns also increase farmers’ incomes and resilience in low rainfall years. With proper conjunctive water management practices, the available tank storage can lead to high water-use efficiency and provide considerable socioeconomic benefits in the command area. The adaptation patterns implemented in HWT demonstrate how water-scarce irrigation systems in Sri Lanka can achieve higher economic water productivity, i.e., generate ‘more income per drop’.