How to deal with 200 mln m3 contaminated river sediments

1. How to deal with 200 mln m3 contaminated river sediments Hilda van de Laar Province of Gelderland The Netherlands

2. Structure of presentation • Dutch river system • The problem • Different approaches • New solution • Conclusion

3. Rhine and Meuse catchment areas

4. Dutch river system river flood plain dike

5. The problem: flooding Usual level Flood wave

6. The problem: flooding Dikeburst? Evacuation

7. Approach: higher dikes?

8. Approach: more space for water

9. New problem • excavate few hundred million m3 soil • contaminated • how to deal with it? • 7 local governments cooperated in finding solutions

10. Standard solution • clean soil can be reused in flood plain • polluted soil has to be cleaned or dumped in large scale sites

11. Consequences standard solution • very expensive • spatial problems • not suitable

12. New solution - 1 • take into account recontamination level • less polluted: reuse unconditionally in flood plain

13. New solution - 2 • take into account recontamination level • more polluted: in smaller sand excavation pits in flood plain

14. Consequences new solution • solution within river system itself -no more spatial problems • save several billion €

15. Political considerations • many parties, many interests • clearly define main goal • accept some pollution will remain

16. Result Large scale measures: excavation of flood plain

17. Result More space for water

18. Conclusions • standard solution was more ambitious, but impracticable – no environmental benefit • new solution less ambitious but enables large scale measures – benefit for environment

19. Result History