The countries of the Western hemisphere share over 70 major transboundary river basins and aquifers. In this context, the primary objective of the Integrated Water Resources Management Section (IWRM) is to support Member States in their efforts to improve the management, conservation, and sustainable use of both superficial and ground water resources by promoting social and economic growth in these regions. Specific actions include the promotion of water governance, the assistance to develop policies, laws and regulations for integrated water resources management, the building capacity in regional, national and local institutions, and the support of the exchange of information through specialized networks in water resources.

Furthermore, in partnership with institutions such as the United Nations Environment Programme (UNEP and UNESCO), the World Bank, and the Global Environment Facility, IWRM acts as a regional executing agency for various water resource management projects being conducted in transboundary, multi-country river basins and aquifers in the Americas.