Water is a key prerequisite for human and economic development, and for maintaining ecosystems. However, billions of people lack access to water and sanitation services, mainly due to poor governance and inadequate investment and maintenance. The situation is becoming more urgent due to increasing pressure, competition and even conflict over the use of water resources. The OECD has been working for many years to address these challenges. The results of recent work are summarised in this report, which emphasises the economic and financial aspects of water resources management and water service provision, the need for an integrated approach (including governance considerations) to address these complex policy challenges, and the importance of establishing a firm evidence base to support policy development and implementation. This report examines: strategic financial planning for water supply and sanitation that balances the key sources of revenues for the water sector - the"3Ts" of taxes, tariffs and transfers; the design and implementation of water pricing strategies that balance financial sustainability with other policy objectives; recent developments in private sector participation in the water sector; and trends and the future outlook of water use in agriculture. It considers both developing and OECD countries and offers concrete recommendations and checklists for action. The report is an invaluable resource for policy makers, academics, NGOs and all others interested in the challenges facing the water sector today.