Ecosystem service valuation in Kalu Oya and Mudun Ela basins, Sri Lanka
Chaturangi Wickramaratne, Avinandan Taron, Mark Mulligan, Sophia Burke, Matthew McCartney
Urban Farm DB summary
A valuation study of the Kalu Oya and Mudun Ela basins, peri-urban sub-catchments of the Kelani River Basin in Gampaha District, Sri Lanka (78 km², population 548,232, with 10.50 km² of wetlands providing services including flood mitigation, water purification, biodiversity support, carbon storage, and urban agriculture), used market-price and benefit-transfer methods to value 13 wetland services at a total economic value (TEV) of USD 25.1-27.6 million for 2025 (USD 12.98-14.45 million/year when excluding static carbon stock). A separate Co$tingNature model assessed 11 ecosystem services across the basin at 30 m resolution, estimating a 25-year TEV of USD 1.67 billion (USD 66.8 million/year); wetlands accounted for only 2.7% of basin-wide TEV but showed the highest per-hectare value (USD 6,807/ha/year). Conservation investment returns were estimated at 23-341% depending on which costs were included, and the study notes that different valuation methods produced varying results depending on their conceptual foundations and data sources.