Water is vital to social and economic development whilst both arable land and water are scarce. Managing water is highly capital intensive, and capital is also scarce. Simultaneously, there are environmental consequences to any intervention in the water cycle whilst the economy depends on the environment. Therefore, for an integrated catchment, economic analyses must be undertaken on the analysis of the impacts of the proposed scheme upon the catchment as a whole INDICE 1. Introduction. 2. What is Economics? 3. The Nature of the Economy. 4. How Do We Choose? 5. Dimensions of Choice. 6. Choosing What? 7. Costs. 8. Social Relations. 9. What is a Better Decision? 10. Institutions for Managing Resources. 11. Implementing Decisions: Inducing Change. 12. Turning Theory into Practice. 13. Project Appraisal. 14. Capturing Water for Human Use: General Issues. 15. Demand Management. 16. Sanitation. 17. Water for Food 18. Flood Management. 19. Hydropower. 20. Navigation. 21. Environment. 22. Information. 23. Implementing Integrated Catchment Management