This publication demonstrates the benefits and added value of implementing intersectoral (nexus) solutions to solve the most typical problems affecting transboundary basins in terms of water quantity, quality, and environment. It is based on a survey of stakeholders worldwide who have experience with solutions and investments that link water management, energy, land/agriculture and/or environment protection, including from nexus assessments and dialogues. Designing, planning, and implementing nexus solutions and investments is in the interest of all policy makers (notably from energy and agriculture). Such nexus solutions - in contrast to sectoral-specific solutions - are associated with lower political risks (broader consensus) and higher levels of coherence with respect to cross-sectoral goals (e.g. climate goals, sustainable development) and broader benefits (multiple interests). The categories of solutions considered include international/transboundary cooperation, governance, economic and policy instruments, as well as infrastructure and innovation, while experiences of financing nexus investments are also discussed here.