Sustainability Science Demonstration Site 3 : Siem Reap and Tonle Sap, Cambodia

Summary of Project Activities and Result

Siem Reap UNESCODue to excessive groundwater pumping under the city of Siem Reap, water pollution, periodic flooding and degraded ecosystems of Tonle Sap, there are current and emerging challenges to the stability of the Angkor World Heritage Site and its building foundations. These complex water and environmental management issues of World Heritage site, biosphere reserve, and urban management nexus were addressed using sustainability science approaches in order to help restore and preserve Angkor World Heritage site’s water management system.

Under this study, three main problems have been identified:

  1. Water pollution by directly dumping garbage near river and wastewater discharge linked to health problems of people living in Tonle Sap and for fish productivity,
  2. Over-exploitation of groundwater which could threaten the stability of temples in Angkor World Heritage Site, and
  3. Deforestation leading to changed flow patterns in Siem Reap River linked to decreased fish productivity.
A research on water balance analysis was carried out and found a water deficit of 229.5 million m3 in 2014 in Siem Reap attributable to the increasing number of tourists to the area. On groundwater, simulation results of scenarios revealed that potential drawdown of groundwater level and land subsidence to Angkor World Heritage Site would occur in all scenarios in a dry year of 50 return period. On land use change, there is a south-north gradient of increasing deforestation, and that the rates of deforestation were at least 1.5 times higher during the period 2000 –2014 in comparison to that of 1989 –2000.


The project recommends the following :

  • Groundwater policies and measures, which include a groundwater use plan or policy to control groundwater use; groundwater pumping information; observation of groundwater and sharing of information to all relevant stakeholders; and groundwater monitoring system.
  • Deforestation reduction and/or avoidance policies and measures, which include action plan to protect the forest upstream of Siem Reap basin, and strong actions and enforcement by the local government to protect the forest and control illegal deforestation
  • Water pollution control policies and measures, which include prohibition of garbage dumping near the source of water or directly into the river, increased awareness of the environmental impact of water pollution by the residents, and an action plan to reduce volume of waste into the river
List of Stakeholders

The stakeholders consulted during the project are:

  • APSARA (Temple in-charge; Conservation Department)
  • Land Management Authority, Siem Reap Provincial Government Office
  • Water Resource Department, Siem Reap Provincial Government Office
  • Department of Tourism, Siem Reap Provincial Government Office
  • Department of Environment, Siem Reap Provincial Government Office
  • Public Works Department, Siem Reap Provincial Government Office
  • Fishery Administration
  • Department of Agriculture, Forestry and Fishery, Siem Reap Provincial Government Office
  • Department of Rural Development, Siem Reap Provincial Government Office
  • Ministry of Water Resources and Meteorology
  • Ministry of Culture and Fine Arts
  • Ministry of Rural Development
  • Siem Reap Water Supply Authority
  • Tonle Sap Authority
  • Cambodia Water Partnership
  • Other organisations: ADB. AFD, JICA, iDE, ITC, OSMOSE
  • Local communities: Kork Kreul village, Ta Prok village, Kork Tachan village, Kork Beng village, Kork Tnot village, Arak Svay village, Tapang village, Thmat Pong village, Angkor Krao village, Khvien village, Kampong Pluk – Floating Village at Tonle Sap lake, Commune and Bakong District of Siem Reap, Sras Srang Village (near Angkor), Psar Leu Market of Siem Reap, Samaki Market of Siem Reap, Old Market of Siem Reap, Angkor Art Center Market

The above stakeholders have been individually interviewed and/or participated in the stakeholders dialogue which took place on 13-14 December 2016 in Siem Reap