Research paper Shatt al Arab River system under escalating pressure: a preliminary exploration of the issues and options for mitigation ALI DINAR ABDULLAH, Department of Civil Engineering, Basra University, Basra, Iraq. UNESCO-IHE Institute for Water Education, Delft, The Netherlands. Email: a.abdullah@unesco-ihe.org, alidinar77@gmail.com (author for correspondence) ILYAS MASIH, Senior Lecturer in Water Resources Planning, Department of Integrated Water Systems & Governance, UNESCO-IHE Institute for Water Education, Delft, The Netherlands. Email: i.masih@unesco-ihe.org PIETER VAN Der ZAAG, Professor of Integrated Water Resources Management, Water Resources Section, Delft University of Technology, Delft, The Netherlands. UNESCO-IHE Institute for Water Education, Delft, The Netherlands. Email: p.vanderzaag@unesco-ihe.org USAMA F.A. KARIM, Lecturer in Geotechnical Engineering, Civil Engineering and Management, Engineering Faculty, University of Twente, Enschede, The Netherlands. Email: u.f.a.karim@utwente.nl IOANA POPESCU, Associate Professor of Hydroinformatics, Deputy Head of the IWSG Department, UNESCO-IHE Institute for Water Education, Delft, The Netherlands. Email: i.popescu@unesco-ihe.org QUSAY AL SUHAIL, Associate Professor of Geology, Geology Department, College of Science, Basra University, Basra, Iraq. Email: quab1965@hotmail.co.uk ABSTRACT This paper provides a broad description of the current state of hydrological and geographical characteristics of the Shatt al Arab River (SAR), and analyses the severe decline in water quantity and escalating levels of salinity. The analyses cover SAR as well as all contributing rivers and Mesopo- tamian Marshlands, which is essential to present a holistic picture of the issues. The analyses are based on the most recent data, though limited, on water availability, water resources development and management infrastructure, and water quality status. The study shows that the water inflows have sig- nificantly reduced and the water quality status has deteriorated to alarmingly high levels, especially from Basra to the river mouth. The crisis can only be averted through the cooperative water management initiatives taken by all the riparian countries, which require a paradigm shift from the current approach of unilateral water management planning to international cooperation and management on the shared water resources. The crisis mitigation strategies should find ways of increasing inflows and improving water quality from the upstream source rivers. At the same time, local measures are required to avoid drainage of poor-quality domestic and industrial effluents and highly saline water from the marshes into the SAR. These efforts should be supported by sound scientific information, which is also limited at the moment. Keywords: Shatt al Arab; water availability; salinity; water resources management 1 Introduction The Shatt al Arab River (SAR) is formed by the confluence of Tigris and Euphrates rivers in Southern Iraq near the city of Qurna (Figure 1). During its course to the Gulf, SAR receives waters from the Karun River. Some other small streams also add water to it. Among them is the Sweeb River bringing water from the Hawizeh marshes which are fed mainly by the Karkheh and the Tigris Rivers. Thus, the SAR receives waters originating from watersheds of the indicated rivers located in Turkey, Syria, Iran and Iraq. The river also serves as a boundary between Iraq and Iran 8 km upstream of the inlet of the Karun River through to the SAR estuary. The SAR has been the source of water for agriculture in the region, providing water Received 2 October 2014. Accepted 12 January 2015. ISSN 1571-5124 print/ISSN 1814-2060 online http://dx.doi.org/10.1080/15715124.2015.1007870 http://www.tandfonline.com 215 Intl. J. River Basin Management Vol. 13, No. 2 (June 2015), pp. 215–227 # 2015 International Association for Hydro-Environment Engineering and Research