Stef has worked with governments, NGOs, development banks and consultants across all areas of the international water sector: from analysing the lifetime costs of services and how they can be financed, to developing institutional arrangements and monitoring their effectiveness. He brings that analytical rigour to strategic advisory work, based on more than 25 years of experience across more than 25 countries in Europe, Latin America, Africa and Asia – turning research findings into practical decisions and investment strategies. In an organisation known for thought leadership, he builds the tools that enable others to put those ideas into action.
Over the past years, he has taken on a more internal management and leadership role, with responsibilities for business development and financial management. In 2026, Stef has become CEO of Riva The Netherlands.
He has an MSc in Irrigation and Water Engineering from Wageningen University, and is based in The Hague.
A few highlights
- 25 years of generating research, evidence and tools that have helped reshape how governments, INGOs and development banks across Latin America, Asia and Africa approach the life-cycle costing, financing and sustainability of water services and water resources management
- Director, IRC Netherlands (since 2024) – executive responsibility for a team of 30, leading business development and strategy across the Netherlands and Europe, and spearheading IRC's transition to a nationally-led network model
- Managing large-scale grant programmes including “Building sustainable WASH systems”(funded by the Dutch Ministry of Foreign Affairs) at 1.5 million Euro/year since 2017, and WASH Systems for Health Facility (funded by the FCDO of the UK Government), a £3 million knowledge programme across six countries, linking essential water and sanitation systems strengthening to health impacts
- Pioneer of the multiple-use water services concept – designing systems that serve domestic and productive water needs simultaneously
- Advisory work with the Inter-American Development Bank, World Bank, DGIS, Agence Française de Development as well as with international NGOs
- Served terms as Executive Steering Committee member, Rural Water Supply Network; Secretary, Multiple Use Services Group; Editorial Board, Water Alternatives journal
- Working languages: Dutch, English, Spanish and Portuguese