The commonly accepted definition of integrated water resources management (IWRM) is “a process which promotes the coordinated development and management of water, land and related resources, to maximise economic and social welfare in an equitable manner, without compromising the sustainability of vital ecosystems” (Global Water Partnership 2000). IWRM recognizes water both as a natural resource critical to society and economy and as an integral component of all ecosystems. While discussions over the merits of the IRWM approach continue (e.g. Jeffrey and Gearey 2006; Mukhtarov and Gerlak 2014), it is the major policy concept in place in over one hundred countries (Conca 2006; UNEP 2012a). IWRM is a progressive tool for reform, requiring strong political will for change, and contextual embedding in specific policy problems. However, it is not a panacea for all complexities of water governance (Ingram 2013). The Organisation for Economic Co-operation and Development (OECD) Principles of Water Governance have relevance to IWRM, emphasizing trust between stakeholders. A complementary approach recognizing the buffering capacity of lakes, wetlands and standing water systems is integrated lake basin management (ILBM), which focuses on “gradual, continuous and holistic improvement of basin governance by basin stakeholders” (Research Center for Sustainability and Environment-Shiga University and ILEC 2014).
The SDG 6.5 target calls upon all countries to implement IWRM at all levels by 2030, including through transboundary cooperation. Likely transboundary impacts on water resources are also often addressed in the procedures under the Espoo Convention and its Strategic Environmental Assessment (SEA) Protocol. To facilitate transboundary water system assessments and management, UN Environment, in collaboration with the Global Environment Facility (GEF) and partners, prepared a global assessment of the status of transboundary lakes, rivers, aquifers and small island groundwater systems, large marine ecosystems and open oceans, Transboundary Waters Assessment Programme (TWAP), (UNEP 2011). The International Groundwater Resources Assessment Centre (IGRAC), a TWAP partner, developed a groundwater information management system to tackle the paucity of standardized quantitative realtime data on key groundwater parameters, and underlined the lack of adequate groundwater governance at all levels.
Recent developments in international water law have significantly strengthened the legal basis regarding shared still (lentic) and flowing (lotic) surface waters and groundwaters. The 1997 Convention on the Law of the Non-navigational Uses of International Watercourses (UN Watercourses Convention) entered into force; the 1992 Convention on the Protection and Use of Transboundary Watercourses and International Lakes (UNECE Water Convention, as amended 2013) was opened to all United Nations member states; and the International Law Commission’s 2008 Draft Articles on the Law of Transboundary Aquifers were commended to governments by the United Nations General Assembly. The two conventions, now operating in tandem at the global level, act as an important catalyst for the revision of existing agreements and negotiation of new river, lake and aquifer agreements at basin scale. Financing to support implementation of existing agreements remains a challenge. They are complemented by the United Nations Framework Convention on Climate Change, the Convention on Wetlands of International Importance especially as waterfowl habitat (Ramsar 2016) and the Convention on Biological Diversity (Convention on Biological Diversity [CBD] 1992), which address the protection of water-related ecosystems. Regionallevel instruments for water management include the EU Water Framework Directive (European Union 2000).