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Recherche et développement régional durable

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Corinne Larrue

Session 2. La précaution et le développement régional durable : l'exemple des risques naturels / The precautionory principle and Sustainable regional development: the example of naturel risk

Flood defence along the Rhine and the Meuse, the irma-programme: preliminary results and recommendations

Jacqueline Laman

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Note portant sur l’auteur1

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INTRODUCTION

1Water is the main topic for the 21th century. This was stated over and over again during the World water conference and forum in the Hague in April this year. Today in this conference Region: Cornerstones for Sustainable development I may tell you about the experience of the IRMA-programme and its contribution to a sustainable approach concerning flood prevention in the European context... I hope I can show you that the IRMA approach has given us all a lot of experience. Also that the way of co-operation can be adopted for other river basins.

2The EU INTERREG-IIC IRMA-PROGRAMME was established after the near catastrophes along Rhine and Meuse of 1993 and 1995. It aims at a new transnational approach towards sustainable flood prevention and flood control. So far the programme has proven to be successful. At the end of 1999 a number of 153 projects have been approved. These projects will be completed before the end of 2001, when the programme ends. IRMA contributes € 141,077,000. National authorities contribute approximately twice this amount.

3The projects implement the IRMA goals that were defined at the start. They cover all themes and measures that were set: measures in catchment areas, in the major riverbeds and improvement of knowledge and co-operation. Projects will be executed in Switzerland, France, Luxembourg, Belgium, Germany and the Netherlands.

4Spatial planning as a tool for sustainable flood prevention, methodologies to raise awareness and translate this into effective decision making processes, new transnational contacts in scientific co-operation, innovation of techniques for indirect discharge of residential and industrial rainwater, dyke relocations, new interregional co-operation and co-ordination: some of the items where significant progress has been and will be enhanced by IRMA-projects.

5The demands that transnational water-systems set for real EU co-operation are clearly recognised on a broad basis. Authorities at different levels realise that it is common sense to enhance safety against foolding by co-ordinating efforts. However it is not so that the final objectives of a sustainable attitude towards flood management control are fully reached within the present IRMA-impulse.

6All member States working together under the IRMA programme recognised that new approaches were necessary. One of these was the necessity of an integrated approach where spatial planning and water-management were linked together. This new policy has already been broadly adopted by the member states.

7Improvement of the Spatial conditions in areas where the population is living was priority one (damage prevention). The short running time of the programme resulted in the selection of pilot projects. The character of these projects were also: no-regret projects.

8The programme will be seconded by a ex-ante, a ongoing evaluation and a ex-post evaluation. This gives in the end the possibility to measure the results as well in terms of new approaches as well as in terms of the realised indicators. These results will in the end support the discussion in the way where sustainable flood prevention and flood control in the catchment areas of the Rhine and Meuse have been succesfull.

1. FROM THE SOURCE TO THE SEA: ALTERING DEMANDS FOR SOUND WATER MANAGEMENT

9The conditions that the river-basins of Rhine and Meuse pose to it's inhabitants vary from source to sea. Effective water management in the Alps demands a different approach from the safety requirements in polders of the low-land areas. In Switzerland response as the water flow changes must be swift and adequate. Flooding as occurred recently in Brigg, is rare and the warning time is very limited. Devastation can be enormous in a very short time, especially when mud slides occur. Precaution is very important in Swiss circumstances. Building on the banks of mountain brooks, that with heavy rain change in mighty rivers is avoided. Aforestation along there banks that might cause severe damage downstream is discouraged.

10In the upper Rhine in Germany and the transborder of France the historical riverbed areas have been separated from the main stream (80 %). Now much efforts take place to restore these floodplains in order to enlarge the retention capacity.

11In the middle part of Germany the Rhine is confined in an elevated area. High water there does not impose serious threats, except for cities and villages with low parts adjacent to the river. Prevention of flooding of these parts is a local, technical and costly matter. There are no threats of inundation of large areas. In the lower part of Nordrhein-Westfalen and the Netherlands this situation is totally different. Dykes protect vast areas of arable land as well as industrial areas, villages and cities. Risks of floods can be predicted within a limited number of days. Evacuation is complicated but possible.

12Along the Meuse there is also a difference between the elevated upstream areas among Meuse and Meurthe in France and Belgium and the downstream part in the Dutch low-lands. In France and Belgium low lying parts along the river can be heavily damaged by flooding. In the Netherlands large areas with urbanisation can be flooded. The dynamic amplitudes of the Meuse are higher as is the case for the Rhine.

13The IRMA-programme applies to all these parts of the riverbasins of Rhine and Meuse, with their varying conditions. Measures in upstream areas have an impact on downstream areas in terms of quantity and sometimes also quality. This also means that adequate spatial functions can support the maintenance of the riversystems. Thus the IRMA programme focuses on an integrate spatial planning and water management. In the first figure gives a scematisation of the changing conditions from the source to the sea and the effect this has on the demands for safety against flooding.

14The projects that have been approved in the IRMA-programme fit within the defined theme's and measures.

2. PRIORITY FOR MEASURES IN THE CATCHMENT AREA: RESTORATION OF TRIBUTARIES, INDIRECT URBAN RAINWATER DISCHARGE AND RAISE AWARENESS AND KNOWLEDGE

15It is clear that measures in the major beds of rivers alone are not enough to cope with the future threats of flooding. Sea level rise and climatic changes will have a strong impact on the river-dynamics in the nearby future. The maximum discharge of water through the main rivers is expected to rise considerably during the next decades. The amplitude of the water-level in the major riverbeds will turn higher, both in circumstances with high and in circumstances with low water. The latter will pose economic threats in shipping and transportation. High water will have a negative impact on damage potentials. Accordingly measures have to be intensified and new projects have to be started in different places.

16In this respect it is obvious that IRMA was only a first and relatively small step. Sustainable and cost effective solutions lay primarily upstream. Preventing direct rainwater discharges from urban areas must be applied in the whole catchment areas of Meuse and Rhine. This is the only way to prevent water from reaching the major rive beds. Changing land-use practices along tributaries and major river beds and raise awareness, know-how and transnational co-operation can also contribute to more structural solutions and thus to a more sustainable use of water systems.

17Examples of the projects under these measures are: (in rural areas)

  • restoring overflow areas: relocating economic activities and removing buildings and other obstacles in special areas that can be deliberately inundated so as to reduce the discharge;

  • restoring meanders and old river branches: in the past, the meanders of rivers have been cut off and river branches isolated from the mainriver. By restoring the meanders and old branches, the river's storage capacity increases, thereby reducing the discharge;

  • re-afforestation projects: forest areas can absorb more water than meadow land, and obviously much more than built-up areas, the increase in absorption benefits not only the reducing of the discharge but also supports the increase of the waterlevel;

  • making provisions to purchase land. Enlargement of the former overflow areas will increase the retention in the upstream parts of the catchment areas.

18Examples in urban areas are:

  • creating green zones in residential areas;

  • improving porosity of the soil;

  • enforcing measures targeting water retention in local building regulation;

  • partial uncoupling of rainwater drains from sewer system.

19Given the above mentioned types of measures many IRMA projects resulted and are now being executed. In the IRMA-programme the allocation to these kind of measures was 38 M € (26 %) of the total budget. There were abundant initiatives.

3. DYKE RELOCATION AND CREATION OF RETENTION AREAS

20There are different ways of flood prevention. Safety along the major river streams and some of it's tributaries make it necessary to take measures in the river bed itself. Increase the flow and retention capacity by excavation of the riverbed and enhance safety for adjacent settlements by constructing dykes in successfully applied since the Middle ages.

21To increase the river capacities further by dyke relocation inland and to store peak of flood waves by creating new inland retention areas are fairly new techniques. They have not been applied the past century. These measures are relatively expensive and demand co-ordinated efforts by various authorities, as well as an intensive communication with the people concerned.

22It is one of the major assets of the IRMA-programme that for the first time the theory is being put to practice in a lot of places. A large number of dyke-relocation and the restoration or creation of retention reservoirs in especially Germany and the Netherlands have been allocated IRMA subsidy. In this point IRMA clearly succeeded in accelerating the application of a new technique, that seems to be more effective and sustainable than the continuation of the existing techniques in dyke enforcement.

23Thus IRMA is also supporting national initiatives to take precautionary measures and prevent new intensive economic use of nature or arable land along major riverbeds.

24The measures under this theme are:

  • broaden the river beds

  • remove obstacles

  • construct side channels

  • deepen rivers

  • relocate dikes

  • create overflow areas

  • create retention areas

25The IRMA-programme consists of 153 study and execution projects which have either been completed or are currently being implemented. The set-up has encouraged forms of regional, inter-regional and international co-operation that are expected to last beyond the end of the programme. Besides co-operation and knowledge transfer, the IRMA-programme is expected to produce a number of quantifiable indicators. The following list of anticipated results are based on the indicators specified in the project proposals. The final impact of all the various projects is expected to be larger.

Projected results of the IRMA programme, based on the indicators specified in the project proposals

  • The projects will reduce the peak discharge by 0.5 % to 20 %;

  • The projects will reduce the maximum flood water level in the vicinity of the project site, with:

  • maximum water levels being lowered approximately 140mm on average (ranging from 2mm to 1,200mm reduction);a total of 708 square kilometres of land will be converted to more appropriate uses so as to diminish potential flood damage;

  • taken as a whole, the projects along the river Rhine and Meuse will apply the concept of "room for the river" and increase the floodplain by approximately 215 square kilometres;

  • within the entire catchment area of the rivers Rhine and Meuse, 368 square kilometres (including the 215 square kilometres along the main rivers) of potential retention areas are being restrored;

  • it is expected that the projects under theme 3 will provide more than 36 million inhabitants (60 %) living in the catchment area with more detailed information about water management, with 22 million of these people (36 %) actively being warned about flood emergencies;

  • more than 173.000 square kilometres of the Rhine-Meuse catchment area (90 %) will be covered by a hydrological and/or hydro-dynamical model (the models overlap in part), with a detailed cartographic analysis being performed on 76.000 square kilometres of this (40 %) to determine the extent of the flooding and pave the way for more appropriate spatial planning;

  • the models cover a total of almost 17.000 kilometres of waterway within the Rhine-Meuse catchment;

  • a total of 103 kilometres of previously straightened stretches of rivers and tributaries are the subject of a re-meandering and redevelopment project;

  • approximately 215 million cubic metres of additional retention capacity is expected to be created, the bulk of this being along the river Rhine;

  • the projects deal with spatial development and the implications for flood prevention and risk analysis.

26The budget for the IRMA projects is about 86 M euros (60 %) of the budget. In comparison with f.i. the action programme of the Rhine of the IKSR the IRMA projects are just a few % of all actions that should be carried out in the forthcoming decades.

Improve knowledge

27Changing the habit of people often has a strong impact on the acceptance of these changes. Therefore raising awareness is an important factor. Besides improving knowledge is necessary in order to support the new policies and innovative actions.

28Some of these are:

  • promote good practice and exchange of information

  • mapping endangered areas

  • developing information systems

  • developing early warning systems

  • citizens awareness projects

29Under the IRMA programme 16 % of the budget will support actions under the theme 3, (see table 1).

30Transnational approach was an important issue under this programme. Several studies with a transnational co-operation are carried out at this moment. One example is the scientific umbrella Sponge project. Under this project 13 sub project are being carried out. The total budget is 14.5 million Euros of which 5 millions Euros EU funding. In the several projects universities and research institutions are working together. An impressive transnational co-operation is here at work and apart from this a sustainable network of scientists has been formed.

31The main issues being in study are listed under 6 clusters:

  • new hydrological and hydraulic models for various river stretches

  • vulnerability assessment

  • risk maps in Rhine and Meuse basins (case studies)

  • improved flood warning systems

  • instruments for decision support and raising public awareness

  • demonstration of decision support in watermanagement and spatial planning

32Apart from intensive co-operation during the execution phase of the project, some working conferencies have been planned. As well as the results of all studies will be published in an overall report.

33This umbrella project is a good example for transnational cooperation, transfer of knowledge, networking and synergy between scientists and end-users.

CONCLUSION

34The projects carried out under the IRMA programme are just the first step in the right direction. A follow-up of EU-commitment in high water prevention along the major river-basins is necessary.

35The follow-up should focus especially on measures concerning indirect discharge of rainwater and restoration of tributaries in catchment areas as well as on the river basin flow -of. The impact of rainfall and seasonal spread on the distinctive geological and geomorphological underground and the run-of is not sufficiently known.

Table 1: Fact and figures on the IRMA-programme's 153 projects: type of measure, objective and indicator; IRMA allocated subsidy and the deviation from the original budget.

Table 1: Fact and figures on the IRMA-programme's 153 projects: type of measure, objective and indicator; IRMA allocated subsidy and the deviation from the original budget.

Notes

1 Programme IRMA, Den Haag, The Netherlands.

Table des illustrations

Titre Table 1: Fact and figures on the IRMA-programme's 153 projects: type of measure, objective and indicator; IRMA allocated subsidy and the deviation from the original budget.
URL http://books.openedition.org/pufr/docannexe/image/1670/img-1.jpg
Fichier image/jpeg, 1,4M

© Presses universitaires François-Rabelais, 2002

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