How to deal with 200 mln m3 contaminated river sediments

Hilda van de Laar

Province of Gelderland

The Netherlands

Structure of presentation

Dutch river system The problem Different approaches New solution Conclusion

Rhine and Meuse catchment areas

Dutch river system

river flood plain dike

The problem: flooding

Usual level

Flood wave

The problem: flooding

Evacuation

Dikeburst?

Approach: higher dikes?

Approach: more space for water

New problem

excavate few hundred million m3 soil

contaminated

how to deal with it?

7 local governments cooperated in finding solutions

Standard solution

clean soil can be reused in flood plain

polluted soil has to be cleaned or dumped in large scale sites

Consequences standard solution

very expensive spatial problems

not suitable

New solution - 1 take into account recontamination

level less polluted: reuse unconditionally

in flood plain

Reuse as soilExcavate soil

New solution - 2 take into account recontamination

level more polluted: in smaller sand

excavation pits in flood plain

Fill with contaminatedriver sediments

Excavate minerals(sand, clay, stones)

Consequences new solution

solution within river system itself -no more spatial problems

save several billion €

Political considerations

many parties, many interests clearly define main goal accept some pollution will remain

Result

Large scale measures: excavation of flood plain

Result

More space for water

Conclusions

standard solution was more ambitious, but impracticable – no environmental benefit

new solution less ambitious but enables large scale measures – benefit for environment

Result

History