Planning for flood protection and ecology
The ecological orientation of flood control is more topical now than ever. Water development and risk management concepts of the flood risk management are to provide the respective planning foundations.
Our brooks and rivers are exposed to a great number of different types of stress due to different types of utilisation. All in all, only 40 % of the running waters showed an ecologically satisfactory status in 2018, more than 60 % failed to reach the environmental objectives of the Water Framework Directive. The causes of it are predominantly interference in water structures and runoff conditions due to hydroelectric power plants or constructions for the purpose of flood protection.
In the light of the implementation of the National Water Management Plan the ecological orientation of hydraulic engineering is more topical now than ever. Brooks and rivers are to be natural habitats in a diverse cultural landscape. In order to be able to reach the objective of a good ecological status and/or a good ecological potential laid down in the Water Framework Directive for all waters in Austria, the principles of ecological flood protection must be consistently implemented in all plans and measures of the flood risk management.
Natural water development means: more space for the rivers
Over the past decades, the development of housing and business settlement has provoked a vast increase of the building area all over Austria. Many areas along our running waters, in flood plains and hazard zones have been built up as well. This constitutes a problem for flood control, as these areas are urgently needed to ensure safe drainage to manage floods. The flood events of the recent years have clearly demonstrated which amount of damage results from that, and that technical methods alone cannot ensure protection against floods.
Therefore modern flood control relies even more on preventive measures. This means: Allowing rivers as much space in non-built-up areas as they need for the drainage and retention of floods. In any case, protective hydraulic engineering together with spatial planning will, in future, have to keep the remaining flood drainage and retention areas even more consistently clear of higher value types of utilization.
Giving the rivers more space will, in any case, also bring about advantages for the ecology. Gravel banks and steep banks, riparian woody plants and riverine forests are essential elements of structurally rich and ecologically intact rivers. Taking into consideration appropriate flood control for the people living nearby it is attempted to reach a good ecological water status, also in the case of existing flood control facilities. The passability of running waters for fish and other aquatic animals is to be improved as well.
The new Water Development - Risk Management Concept (GM-RM-Konzept)
In order to be able to harmonise the goals of the National Water Management Plan (NGP Nationaler Gewässerbewirtschaftungsplan) with those of the National Flood Risk Management Plan (NMP Nationaler Hochwasserrisikomanagementplan) and to take into consideration also other types of utilisation and demands placed in waters, the flood risk management has developed the Water Development and Risk Management Concept as a superordinate planning basis in river basin areas, which comprises the following planning steps:
- Preliminary study: Conception of planning steps, delimitation of fields of work, definition of working packages;
- Inventories: Identification of the status quo, presentation and analysis of the situation in terms of water management and water ecology;
- Definition of goals: formulation of an integrative guideline on the basis of sectoral goals for flood control and ecology, harmonised with the objectives of the National Water Management Plan and the National Flood Risk Management Plan;
- Concept of measures: Definition of measures and combinations of measures, focus actions and priorities, harmonised with the agencies competent for the National Water Management Plan and the National Flood Risk Management Plan;
By means of accompanying public relations work the acceptance of the planning in the regions concerned is improved. The cooperation between the competent technical and administrative areas is strengthened and results in synergies with the implementation of measures. A technical guideline for the Water Development and Risk Management Concept (GE-RM-Leitfaden) is available for download.
With the integrated LIFE project “LIFE IP IRIS AUSTRIA – Integrated River Solutions in Austria“ WD-RM (Water Development -Risk Management) concepts will be established and implemented on seven rivers in Austria in the course of the next few years. In the LIFE-IRIS project plans and measures with the technical fields of water ecology, environmental protection and flood control for the purposes of an integrative river basin management along these rivers are intensively and concretely coordinated and finally the implementation of the measures is evaluated.
On the basis of these practical experiences the WD-RM guideline is to be further developed and improved.