Aquifers of the Scheldt basin Testing the guidance document WATECO & IMPRESS groups Gabrielle Bouleau (ENGREF) & Arnaud Courtecuisse (AEAP)
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 recharge of groundwater, with the aim of achieving good groundwater status at the latest 15 years after the date of entry into force of this Directive,
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 ?
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
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
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
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
Relevant units: assumptions 70 % Pool model
Relevant units in Lille area carboniferous
Relevant units in Lille area Carboniferous
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
Natural recharge of each unit Different definitions: different values
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
Abstractions from each unit
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
Structure of the demand Data for 2000
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
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
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
Gap assessment Target for the testing: 70 % m3/day needed
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
Cost-effectiveness of measures Reduction of losses Communication campaign for reduction of the water demand
Communication campaign Global cost of Euros for Lille Area Less water income Less maintenance ? Higher price ?
Conclusion of the testing Relevant scale: public water services + self services to take into account possible shifts Natural recharge and abstractions assessment Strategic information Common monitoring needed Indirect effects of water savings feedbacks on price or maintenance