为什么以及何时水会计很重要：运营任务组的指导说明（英）2026

A Guidance Note for Operational Task Teams Poolad Karimi, David Molden, Rita Cestti,Svetlana Valieva, Ruyi Li, and Amal Talbi About the World Bank Group Water Department The Water Department of the World Bank Group integrates financing,expertise, and implementation into a unified platform. By leveraging theinstitution’s global knowledge alongside country-specific investments, thisapproach enhances the capacity to deliver transformative solutions thatsupport sustainable growth for nations. Please visit us atwww.worldbank.org/wateror follow us on:@WorldBankWater. About GWSP This publication received the support of the Global Water Security& Sanitation Partnership (GWSP). GWSP is a multidonor trust fundadministered by the World Bank Group’s Water Department andsupported by Australia’s Department of Foreign Affairs and Trade;Austria’s Federal Ministry of Finance; Denmark’s Ministry of ForeignAffairs; the Netherlands’ Ministry of Foreign Affairs, the GatesFoundation; Spain’s Ministry of Economy, Trade and Business; theSwedish International Development Cooperation Agency, Switzerland’sState Secretariat for Economic Affairs; the Swiss Agency for Developmentand Cooperation; and the United Kingdom Foreign, Commonwealth andDevelopment Office. Please visit us atwww.worldbank.org/gwspor follow us on:@TheGwsp. WhyandWhen WaterAccounting Matters A Guidance Note for Operational Task Teams Poolad Karimi, David Molden, Rita Cestti,Svetlana Valieva, Ruyi Li, and Amal Talbi © 2026 International Bank for Reconstruction and Development / The World Bank1818 H Street NW, Washington, DC 20433Telephone: 202-473-1000; Internet:www.worldbank.org This work is a product of the staff of The World Bank with external contributions. The findings, interpretations,and conclusions expressed in this work do not necessarily reflect the views of The World Bank, its Board ofExecutive Directors, or the governments they represent. The World Bank does not guarantee the accuracy, completeness, or currency of the data included in this workand does not assume responsibility for any errors, omissions, or discrepancies in the information, or liabilitywith respect to the use of or failure to use the information, methods, processes, or conclusions set forth. Theboundaries, colors, denominations, links/footnotes and other information shown in this work do not implyany judgment on the part of The World Bank concerning the legal status of any territory or the endorsementor acceptance of such boundaries. The citation of works authored by others does not mean the World Bankendorses the views expressed by those authors or the content of their works. Nothing herein shall constitute or be construed or considered to be a limitation upon or waiver of the privilegesand immunities of The World Bank, all of which are specifically reserved. Rights and Permissions The material in this work is subject to copyright. Because The World Bank encourages dissemination of itsknowledge, this work may be reproduced, in whole or in part, for noncommercial purposes as long as fullattribution to this work is given. Please cite the work as follows: Karimi, Poolad, David Molden, Rita Cestti, Svetlana Valieva, Ruyi Li, andAmal Talbi. 2026. “Why and When Water Accounting Matters: A Guidance Note for Operational Task Teams.”World Bank, Washington, DC. Any queries on rights and licenses, including subsidiary rights, should be addressed to World Bank Publications,The World Bank Group, 1818 H Street NW, Washington, DC 20433, USA; fax: 202-522-2625; e-mail:pubrights@worldbank.org. Cover design:Bill Pragluski, Critical Stages, LLC. Cover photo:Arne Hoel/World Bank. Contents AcknowledgmentsvExecutive SummaryviiAbbreviationsxi1.Introduction1Note2Reference22.Water Accounting—What, Why, and When3References53.Water Accounting Basics and Tools6Water Accounting Basics6Water Accounting Tools13Notes17References174.Water Accounting for World Bank Operations19Applying Water Accounting through the Project Cycle19Applications of Water Accounting within World Bank–Supported Projects21Water Accounting by Subsector21Notes33References335.Institutionalizing Water Accounting366.Implications for Future World Bank Support of Water Accounting41Appendix A. Case Studies Illustrating the Applications ofWater Accounting43Appendix B. Steps in Implementing Water Accounting73Bibliography75Glossary76 WHY AND WHEN WATER ACCOUNTING MATTERS: A GUIDANCE NOTE FOR OPERATIONAL TASK TEAMSIII BOXES 1.1.Water Accounting Matters13.1.Remotely Sensed Data—A Game Changer for Water Accounting134.1.Irrigation Efficiency and Water Accounting244.2.Water Accounting and Water Storage26 FIGURES 2.1.Role of Water Accounting in the Project Cycle of IWRM Implementation43.1.Conceptual Illustration of Water Accounting at Different Scales73.2.Definition Diagram of the Time and Spatial Domain, Internal and ExternalFlows, and Changes in Storage83.3.Definition Diagram of Water Accounting93.4.Schematic of Water Accounting Appr