1. 1 REVIEW OF THE METHODS FORWATER RESOURCES PROSPECTIVE: WHAT CAN WE LEARN FOR THE WATER FRAMEWORK DIRECTIVE? Ruud Van der Helm (ENGREF, France) Vanderhelm@engref.fr and Adeline Kroll (IPTS, JRC-EC, Spain) Adeline.Kroll@jrc.es Lille III Conference 18-19/03/02

2. 2 20th century, water planning focused on projections using variables such as e.g., populations, per-capita water demand, agricultural production, levels of economic productivity etc. However, these projections on water demand typically ignored any analysis of human needs, water required for ecosystems or actual regional water availability Next step to this approach (still) is to identify projects able to bridge the gap between projected water demand and estimated available water supply Basic assumption is in this approach that building more physical infrastructures could meet projected shortfalls Water Projections at the Global Level

3. 3 …lies between those who believe that the problem is primarily technical (e.g., more efficient technology) and those who believe that reorganisation and co-ordination of water policy process will rationalise decisions toward a water- demand planning. Today’s debate...

4. 4 30 Years of Global Water Projections Early models (e.g., Nikitopoulos 1962) broke down water withdrawals per sector (agriculture, domestic, industrial) and by regions. Basic assumption was to estimate water needs using average annual per capita water withdrawals per sector based on population estimates; Alternative models (“business-as-usual” with alternative model) introduced by L’vovich (1974) who first considered water-reuse; In view of Mar de Plata (Argentina, UN Water Conf, 1977), De Mare (1976) used works by Russians Kalinin and Shiklomanov (1974) who first considered reservoir losses by evaporation;

5. 5 Sustainability criteria and limits introduced by Gleick (1997); Policy drivers introduced by Raskin et al. (1997) with their “Reference” BAU and “Policy” models (socioeconomic conditions considered) “WaterGap:” model (Alcamo et al. 1997) evaluated water use for nearly the entire land surface of the world; Recently, models have increasingly gained in complexity (sub and sub-sub models…) 30 Years of Global Water Projections

6. 6 Global Water Projections: What’s Next? Early global water projections turned out to be wrong: greatly overestimated water demand by about 50% of what was expected 30 years ago; Depended on straightforward extrapolations of existing trends; Ignored environmental, ecological and social variables now considered the most recent global water projections.

7. 7 4 Cases World Water Vision (World Water Council) Participatory Vision Development based on reference scenarios Globesight (Global Foresight) (CWRU Ohio USA) Systems Dynamics with ‘Human in the loop’ WaterGAP (Water Global Assessment and Prognosis) (CESR University of Kassel) Simulation of Resources Dynamics WEAP (Water Evaluation and Planning System) (SEI Boston) Policy Analysis Decision Support System

8. 8 Scenarios

9. 9 Socio-economic driving forces

10. 10 Participation

11. 11 Lessons for the FDW There are more valid answers to foresights Data remains a problem. Interaction between scenarios and modelling Refinement of driving forces Foresights become valuable during their evolution The demand for participation can be answered in different ways ( towards participatory scenario development?)

12. 12 Recommendations Strive towards continuous foresights per river basin Combine scenario Development with arithmetic (modelling) Strive for participation in scenario development Explore to a larger extent existing experiences