Dams in the Mekong: a comprehensive database, spatiotemporal distribution, and hydropower potentials

Abstract

Dams have proliferated along the Mekong, spurred by energy demands from economic development and capital from private companies. Swift dam evolution has rendered many databases outdated, in which mismatches arise from differing compilation methods. Without a comprehensive database, up-to-date spatial assessment of dam growth is unavailable. Looking at future development, hydropower potential specifically within the Mekong remains to be systematically evaluated. In this paper, we offer (1) an open-access and unified database of 810 dams, (2) a spatiotemporal analysis of dams on a sub-basin and country level from the 1980s to the post-2020s, and (3) a 0.05-degree grid-based assessment of the theoretical basin-wide hydropower potential using discharge from the CaMa-Flood model. The dam count of 810 is almost twice the largest existing database, with 364 hydropower dams generating a boom in hydropower capacity from 1,242MW in the 1980s to 68,107MW post-2020s. While China had the largest capacity increase from the 2000s to the 2010s (+16,854MW), Laos has the most planned dams and the highest projected growth post-2020s (+15,282MW). We estimate a basin-wide hydropower potential of 773,454MW, where China and Laos are the highest at around 300,000MW each, together forming 78% of the total potential. Our database facilitates research on dam-induced hydrological and ecological alterations, while spatiotemporal analysis of hydropower capacity could illuminate the complex transboundary electricity trade. Through both spatiotemporal and hydropower potential evaluation, we address the current and future vulnerability of countries to dam construction, highlighting the need for better planning and management in the future hydropower hotspot Laos.