Ancient spillway Cambodia reveals structure built for water storage failed and forced Cambodian Kings to relocate capital

The largest water management feature in Khmer history was built in the 10th century as part of a short-lived ancient capital in northern Cambodia to store water but the system failed in its first year of operation, possibly leading to the return of the capital to Angkor.1

  • 1. "It's not difficult to envisage that the failure of the embankment at Koh Ker -- the largest and most ambitious infrastructure project of the era -- may have had a significant impact on the prestige of the sovereign capital, and contributed to the decision to re-establish Angkor as the capital of the Khmer Empire.", says Dr Ian Moffat, who led the research team, "Our study shows that this ambitious engineering feat was always doomed to rapid failure."

Ian Moffat, Sarah Klassen, Tiago Attorre, Damian Evans, Terry Lustig, Leaksmy Kong. Using ground penetrating radar to understand the failure of the Koh Ker Reservoir, Northern CambodiaGeoarchaeology, 2019

DOI: 10.1002/gea.21757

Ground penetrating radar, probing, and excavation were used to create a contour map of the topography of a buried laterite pavement forming the spillway of a large abandoned reservoir at the Angkorian‐period city of Koh Ker in Cambodia. Calculations of the flow velocity of water through the spillway, based on the topography of the laterite surface, demonstrate that this outlet was even less adequate for passing the flow of water from the Stung Rongea catchment than had been estimated previously by Lustig, Klassen, Evans, French, & Moffat (2018). We argue that this design flaw contributed substantially to the failure of the reservoir’s dike, possibly during the first rainy season after construction, which may have contributed to Koh Ker’s remarkably short‐lived tenure as the political center of the Khmer Empire.