This report presents a summary of the key challenges and opportunities related to financing that contributes to water security and sustainable growth distilling insights from the Roundtable on Financing Water and related analyses. It covers a broad range of water-related investments, including water and sanitation services, water resources management, agricultural water and managing water-related risks (“too much”, “too little” and “too polluted”). It summarises findings from analysis of investments needs and financing capacities, trends in development finance for water and explores how water risks generate financial impacts for corporates. The report highlights options to address the financing challenge by strengthening the enabling environment for investment, making the best use of existing sources of finance, strategic investment planning and mobilising additional finance via a range of financing approaches. Finally, the report sets out a vision for future OECD work on financing water and for the Roundtable on Financing Water.