1. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 1 German experience in assessment of groundwater quantitative status and proposed methodology for Slovenian circumstances Benedikt Toussaint Wiesbaden/Germany

2. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 2 German experience in assessment of groundwater quantitative status …… Topics Topics WFD requirementsWFD requirements WFD weakpointsWFD weakpoints assessment procedures in Germany/Hesseassessment procedures in Germany/Hesse methodology proposal for Sloveniamethodology proposal for Slovenia

3. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 3 WFD requirements concerning assessment of groundwater quantitative status

4. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 4 WFD requirements Art. 1: promotion of sustainable water use based on long-term protection of available water resources Art. 1: promotion of sustainable water use based on long-term protection of available water resources Art. 4: protection, enhancement and restoration of all bodies of groundwater, ensuring a balance between abstraction and recharge of groundwater, with the aim of achieving good groundwater status at the latest in 2015 Art. 4: protection, enhancement and restoration of all bodies of groundwater, ensuring a balance between abstraction and recharge of groundwater, with the aim of achieving good groundwater status at the latest in 2015

5. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 5 WFD requirements Annex II, 2: in the frame of the initial characterisation identification of the pressures to which groundwater bodies are liable to be subject including abstraction and artificial recharge Annex II, 2: in the frame of the initial characterisation identification of the pressures to which groundwater bodies are liable to be subject including abstraction and artificial recharge Annex II, 2: in the frame of the further characterisation information on Annex II, 2: in the frame of the further characterisation information on estimates of the directions and rates of exchange of water between the groundwater body and associated surface water systemsestimates of the directions and rates of exchange of water between the groundwater body and associated surface water systems sufficient data to calculate the long-term annual average rate of overall rechargesufficient data to calculate the long-term annual average rate of overall recharge chemical composition of the groundwater, including specification of the contributions from human activitieschemical composition of the groundwater, including specification of the contributions from human activities

6. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 6 WFD requirements Annex II, 2: review of the impact of human activities on groundwaters Annex II, 2: review of the impact of human activities on groundwaters information on the location of points in the groundwater body used for the water abstraction of at least 10 m 3 /day or for supplying at least 50 persons with drinking waterinformation on the location of points in the groundwater body used for the water abstraction of at least 10 m 3 /day or for supplying at least 50 persons with drinking water information on the annual average rates of abstraction from such pointsinformation on the annual average rates of abstraction from such points

7. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 7 Assessment of good quantitative groundwater status acc. to the WFD Parameter for the classification of qualitative status Parameter for the classification of qualitative status groundwater level regimegroundwater level regime Description of the good quantitative information Description of the good quantitative information The groundwater level in the groundwater body is such that the available groundwater resource is not exceeded by the long-term annual average rate of abstraction.The groundwater level in the groundwater body is such that the available groundwater resource is not exceeded by the long-term annual average rate of abstraction. Accordingly the groundwater level is not subject to anthropogenic alterations such as would result in:Accordingly the groundwater level is not subject to anthropogenic alterations such as would result in: failure to achieve the objectives specified under Art. 4 for associated (surface) waters failure to achieve the objectives specified under Art. 4 for associated (surface) waters any significant diminuation in the status of such (surface) waters any significant diminuation in the status of such (surface) waters any significant damage to terrestrial ecosystems depending directly on groundwater any significant damage to terrestrial ecosystems depending directly on groundwater alterations to flow direction resulting from level changes causing saltwater or other intrusion alterations to flow direction resulting from level changes causing saltwater or other intrusion

8. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 8 WFD weakpoints concerning assessment of groundwater quantitative status

9. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 9 WFD weakpoints focus only on groundwater level, with regard to assessment of groundwater resources analysis of spring yield or of low discharge in surface waters in many cases the better approach focus only on groundwater level, with regard to assessment of groundwater resources analysis of spring yield or of low discharge in surface waters in many cases the better approach no link between poor qualitative groundwater status and thus diminuation of the available groundwater-born drinking water quantity (instead of this attention is paid to conse- quences for ecosystems) no link between poor qualitative groundwater status and thus diminuation of the available groundwater-born drinking water quantity (instead of this attention is paid to conse- quences for ecosystems)

10. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 10 Assessment of groundwater quantitative status in Germany/Hesse

11. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 11 Delineation of groundwater bodies in Hesse (and mostly in Germany) intersection of surface water catchment areas (1,500 to 5,000 km 2 ), to be understand as groundwater body groups hydrogeological sub-regions  124 GWBs  areas on average 173 km 2 Acc. to Art. 2, nr.° 12, WFD groundwater body means a distinct volume within an aquifer or aquifers. The German/Hessian delineation procedure has not always observed this definition.

12. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 12 % Groundwater abstractions in % of long-year annual recharge in the Middle Rhine region GWBs Middle Rhine

13. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 13 Status of groundwater quantity groundwater abstraction artificial recharge surface water and terrestrial eco- systems dependent on groundwater not considered indirectly considered

14. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 14 Initial characterisation of pressures and impacts regarding groundwater abstraction artificial recharge (not considered) groundwater bodies used for abstraction > 10 m 3 /day > 50 persons all groundwater bodies in Hesse WFD criteria long-term abstractions for drin- king, industrial and agricultural water supply, lowering of gw levels when rock and earth is abstracted (quarries/sand pits/open cast coal sites), forking of mines; other major abstractions (e.g. de-watering of swamps, drainage of under- ground pipes)

15. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 15 Methodology approaches for assessing quantitative status of groundwater bodies porous aquifers fractured aquifers karst aquifers analysis of hydrogeological situation assessment based on groundwater level assessment based on groundwater balance combined approach

16. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 16 Some reasons for not considering monitoring wells respectively groundwater level regime only point information only point information sufficiently long time series necessary for sound trend calculation partly rare sufficiently long time series necessary for sound trend calculation partly rare different gw level regime due to different monitoring well design different gw level regime due to different monitoring well design heterogenious network configuration, different monitoring well density heterogenious network configuration, different monitoring well density different hydrogeological features different hydrogeological features hydrogeologically serious data aggregation concerning a GWB as a whole problematic hydrogeologically serious data aggregation concerning a GWB as a whole problematic Hessian approach (and most German Länder): groundwater balance Hessian approach (and most German Länder): groundwater balance

17. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 17 Trend calculation considering anthropogenic impacts on groundwater regime

18. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 18 groundwater balance in fractured and karst aquifers (bodies) status assessment for risk criterion: water rights > 50 % of groundwater recharge Yes: groundwater body "at risk" No: groundwater body "not at risk"

19. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 19 Groundwater recharge in hydrogeological units products: map of groundwater recharge (l/s · km 2 ) map of sum of groundwater recharge related to gw-bodies Collection of all data on water rights for wells product: map on water rights related to groundwater bodies Groundwater balance: groundwater recharge/water rights for gw abstraction Final product: map of the relation between water rights (m 3 /year) and groundwater recharge (m 3 /year) steps to do 1. 2. 3. 4.

20. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 20 groundwater recharge in hydrogeological units (one or more aquifers, not always the nearest one to the surface) products : map of groundwater recharge (l/s·km 2 ) [legend: 0,5 -white- to 9,5 l/s·km 2 -blue-] map of the sum of groundwater recharge related to GWBs (m 3 /a) [legend: 700 to 450 Mio. m 3 /a] 1. step

21. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 21 Rate of long-term annual recharge in the hydrogeologi- cal units in Hesse (in l/s·km 2 )

22. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 22 Sum of groundwater recharge related to the groundwater bodies in Hesse (in m 3 /year)

23. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 23 Collection of all data on water rights for wells (springs only relevant considering surface waters and terrestrial ecosystems dependent on groundwater). product: map on water rights related to groundwater bodies (m 3 /a) [legend: 0 to 60 Mio. m 3 /a] 2. step

24. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 24 Water rights for indivi- dual wells or well gale- ries related to the groundwater bodies in Hesse

25. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 25 groundwater balance: groundwater recharge /water rights for gw- abstraction product: map of the relation between water rights (m 3 /year) and groundwater recharge (m 3 /year) scale: 0 - 33%; 33 - 50 %, 50 - 75 %, 75 - 100 %, > 100 % 3. step

26. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 26 Water rights in % of the long-term annual recharge in the groundwater bodies in Hesse decision of the relevant working group in Hesse: if water rights > 50 % of recharge than GWB assessed as being „at risk“; in other Länder: thresvalue 10 % 17 GWBs (13 %) need further characterisation/assessment

27. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 27 number of groundwater bodies: 124 groundwater bodies „at risk“: 17 Result of initial assessment of groundwater quantity status 4. step

28. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 28 Further assessment of groundwater quantity status real groundwater abstraction data refined data on groundwater recharge artificial groundwater recharge frame condition of geology and hydrogeology

29. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 29 GWB 1 GWB 2 GWB 3 drinking water wells localised in GWB 1, but catchment area mainly referred to GWBs 2 and 3 possible consequence: GWB 1 assessed as being „at risk“

30. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 30 Result of final assessment of groundwater quantity status in Hesse number of groundwater bodies: 124 groundwater bodies „at risk“ acc. 17 to initial assessment: groundwater bodies „at risk“0 acc. to further assessment:

31. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 31 Proposed methodology for assessing the quantitative groundwater status in Slovenia

32. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 32 General proposals because MS have to report by the 22 th March 2005 only use of present and quickly available data renunciation of sophisticated methods, think pragmatically improvement of data pool also later possible and allowed by Commis- sion (full report made by 2008)

33. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 33 Proposed assessment procedure adapted to Slovenian circumstances (commonly karstified formations) Because of hydraulically very complex karstified formations the size of groundwater bodies should be as great as possible (otherwise the hydrogeologically correct delineation of small gw bodies may be very difficult). Should the knowledge on the karst water flow fields be sufficient (based on tracer tests etc.), then the delineation of gw bodies basing on dynamics is to prefer (better than the pragmatic Hessian proce- dure), thus time-spending corrections of the assign- ment of abstractions to their real catchment area can be avoided.

34. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 34 Proposed assessment procedure adapted to Slovenian circumstances (commonly karstified formations) The assessment of the groundwater quantitative status should only be based on the water balance (comparison of abstraction and long-term annual average rate of recharge), not on the groundwater level regime because of the very complex karst hydrogeology. To use abstraction data is the better way than to use water rights, because the water rights usually are higher than the actual abstraction and thus reflect the worst case. Collection of abstraction data should refer only to artificial abstractions, not to springs (naturally surfacing ground- water).

35. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 35 Proposed assessment procedure adapted to Slovenian circumstances (commonly karstified formations) Only long-term abstractions (more than 5 years) by public waterworks, industry, agriculture and others are relevant for the risk assessment. The relation abstraction/recharge assessed as being „at risk“ must be decided politically. Should „rate of rechar- ge“ mean the definition of "available groundwater resources" acc. to Art. 2, nr.° 27, then theoretically a 100 % relation can be accepted (because the ecological demands are covered). Otherwise, the risk-referred percentage must be reduced, a range between 10 % and 50 % may be discussed (the focus of the WFD lies on ecology!). A combined approach is possible, namely a dependence of water rights/abstraction on guidance groundwater levels.

36. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 36 Guidance values of average groundwater levels in dry years Combination of water rights and guidance groundwater levels

37. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 37 Guiding questions considering data management Which data are needed, which data are available? Which data are analog, which data are digital? Are there GIS-conform maps, e.g. with the location of abstraction points? Which institution is owner/user of the data? What are the data transfer paths? And who is the organisator/controller of the data transfer? Which institution has the overall responsibility? When must the work be finished at the latest? Is there a concept considering „Who is doing something, for which reason, and by what time?“

38. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 38 data on gw bodies, hydrogeological units, groundwater recharge data on water rights centralised: Geological Survey of Slovenia ? decentralised: local water agencies centralised GIS application : Geological Survey of Slovenia? Proposal for data collection and GIS application

39. Workshop on WFD implementation, Ljubljana, 9 - 10 September 2004 39 Many thanks for your attention! My personal opinion as foreign hydrogeologist: Because of relatively high precipitations in the predominantly montain- ous Slovenia and the high permeability of the karstified carbonate rocks the rate of groundwater recharge all in all may be sufficient to cover most or all groundwater demands. Therefore the result of assessment will be that only few groundwater bodies are „at risk“ regarding their quantitative status.