Costing and financing of small-scale water supply and sanitation services

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

There is enough money in the world to give everyone safe water and sanitation. The problem is the gap between where capital sits and where it needs to flow. For more than twenty-six years, Catarina Fonseca has worked on closing that gap: building the economic frameworks, financial tools and evidence that help governments and development banks stop treating water as a cost and start treating it as an investment.

She works with finance ministers, development banks and multilateral agencies to identify the changes needed in regulation and institutional set-ups to make essential water services for everyone viable over the long term. Her analyses help governments answer the questions that investors and treasuries always ask first: what will this cost over its whole life, who will pay for it, and will it be sustainable? 

She’s carried out that work across Africa, Asia and Latin America – developing national finance strategies for Ethiopia, Rwanda, Malawi and Cambodia, and advising on investment frameworks for the European Investment Bank, the African Development Bank, the World Bank and the Agence Française de Développement. She also served as independent expert advisor to the Dutch Prime Minister's High-Level Panel on Water Investments in Africa – bringing Riva's analytical depth to the conversations where the largest commitments are made.

Catarina trained as an economist in Lisbon before completing a doctoral degree in Water Sciences at Cranfield University – a combination that explains why finance ministers and district water authorities find her equally credible. She is the author of the Handbook for Finance Ministers on water and sanitation investment, and has written or co-authored more than 100 papers, briefing notes and books that now form the reference library the sector draws on. As a senior associate of Riva and through Pulsing Tide, her own advisory practice, she brings that body of knowledge in-person and online to all corners of the world.

A few highlights

• Author of the Handbook for Finance Ministers – how to make public investment work – the defining reference for governments making the case at the highest political levels
• Independent expert advisor to the Dutch Prime Minister's High-Level Panel on Water Investments in Africa
• National water finance strategies developed for Ethiopia, Rwanda, Malawi and Cambodia – with UNICEF, FCDO and AFD
• WASHCost Director (2008–2013) – a landmark five-year programme costing sustainable water services across four countries, supported by the Bill & Melinda Gates Foundation
• Advisor to the Water Finance Coalition, bringing together national and international public development banks to improve financing for SDG 6 and the Paris Agreement
• More than 100 published papers, books and briefing notes and developed Riva’s Systems Academy finance course 
• Working languages: Portuguese, English, French and Spanish