Aquifers of the Scheldt basin

1. Aquifers of the Scheldt basin Testing the guidance document WATECO & IMPRESS groups Gabrielle Bouleau (ENGREF) & Arnaud Courtecuisse (AEAP)

2. WFD objectives for aquifers • The WFD indicates in Article 4 : (ii) Member States shall protect, enhance and restore all bodies of groundwater, ensure a balance between abstraction and rechargeof groundwater, with the aim of achieving good groundwater status at the latest 15 years after the date of entry into force of this Directive,

3. Questions for the testing • Do abstractions exceed the natural recharge (today and in the baseline scenario)? • If so, what are the possible measures and their cost-effectiveness ?

4. Selection of the case study • Carboniferous limestone • International Groundwater in the Scheldt basin • over-exploited • competition between industries • national strategies to avoid a common assessment • Different definitions of the aquifer • no comparable data

6. Selection of the case study • Chalk aquifer around Lille area • National groundwater in the Scheldt basin • over-exploitation and pollution • alternative resource of the carboniferous limestone • existing coherent data

7. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3. Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

8. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3. Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

9. 70 % Relevant units: assumptions Pool model

10. Relevant units in Lille area carboniferous

11. Carboniferous Relevant units in Lille area

12. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3. Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

13. Natural recharge of each unit Different definitions: different values

14. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3. Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

15. Abstractions from each unit

16. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3.Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

17. Structure of the demand Data for 2000

18. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3.Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

19. Evolution of the demand • no change in the population and economic developments • no change in consuming behaviours • no change in distribution of abstraction • Consequences by the year 2015: • same situation as in 2000, no measure implemented. To be negotiated

20. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3. Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge(gap assessment) • Cost-effectiveness analysis of possible measures

21. Gap assessment Target for the testing: 70 % 10 200 m3/day needed

22. The 3-steps approach • Characterisation of groundwaters • 1. Definition of relevant hydrogeological units • 2. Assessment of the natural recharge of each unit • 3. Assessment of abstractions from each unit • 4. Structure of the demand • 5. Evolution of the demand • Future demand versus natural recharge (gap assessment) • Cost-effectiveness analysis of possible measures

23. Communication campaign for reduction of the water demand Reduction of losses Cost-effectiveness of measures

24. Communication campaign Global cost of 2 550 000 Euros for Lille Area Less water income Less maintenance ? Higher price ?

25. Conclusion of the testing • Relevant scale: • public water services + self services • to take into account possible shifts • Natural rechargeand abstractions assessment • Strategic information • Common monitoring needed • Indirect effects of water savings • feedbacks on price or maintenance