The desire to comply with the European Water Framework Directive, which seeks to promote Integrated Water Management, has led to a large number of proposed projects that in turn make huge demands on the financial and administrative capacity of water managers, who need to combine multiple fields of interest and participation such as agricultural interests, regional economic development, natural values, water safety and water quality issues to complete each project. To achieve these goals, water managers will often need to negotiate and strike alliances with actors in other policy areas such as spatial planning and local and regional economic development. The article first introduces 'boundary spanning' in a water management context. The concept builds on the concept of 'boundary work' as a strategy to arrive at organisational goals – to reduce uncertainty and deal with complexity in the organisational environment. The contribution then discusses briefly two recent innovative regional water projects, both located in the East Netherlands: a retention basin project on the river Vecht and the planning of a new channel, the Breakthrough. It further analyses strategies pursued by 'boundary spanners' and integrates the analysis with that of a focus group workshop and interviews held with Dutch boundary spanners working for Dutch regional Water Management Boards. The cases show that it is preferable to apply boundary spanning strategies earlier rather than later, and that opponents are also aware of this option.