Implementation of the European Water Framework Directive
Watercourses are the lifelines of a landscape. They are characteristic elements of cities and communities. The state capital of Wiesbaden is responsible for their protection.
In urban areas today, watercourses fulfill various functions. They are a habitat for animals and plants, a place for people to enjoy and should drain flood water without causing damage. However, many watercourses have been heavily modified by humans. To positively counteract this development, the European Water Framework Directive was adopted in 2000.
This set binding targets for the member states of the European Union for the improvement of water bodies. In Germany, this European directive was transposed into national law by the "Water Resources Management Act". One important goal is to achieve good ecological status for watercourses.
What does "good ecological status" mean?
What is the condition of the watercourses in Wiesbaden?
Some of Wiesbaden's waters were used for a variety of purposes in the past and have been heavily modified as a result.
Use of the waters:
- Damming the waters to harness hydropower
- Deepening and massive fortification of watercourses to drain wastewater
- Severe straightening for flood drainage
- Laying and piping the watercourses underground
Watercourses flow through our towns and municipalities in straight lines and fixed in concrete channels. This often has nothing to do with "good ecological status". Today, the focus is less on the use of watercourses and more on restoring them to a near-natural state.
The most common obstacles to migration in Wiesbaden are
- heavily straightened streams
- falls
- culverts with a smooth bed structure
- weirs
They impair the passability of living organisms enormously and must be dismantled or made passable in accordance with the requirements of the Water Framework Directive.
How can "good ecological status" be achieved for Wiesbaden's water bodies?
Good ecological status is achieved when the watercourse is upgraded or restored in its function as a habitat for animals and plants. It is crucial that living organisms can migrate in the water body and find differently structured areas. This should enable them to find spawning grounds or areas for mating.
The following structures must be created for this purpose:
- Spawning and recreation zones
- Alternating fast-flowing and almost stagnant areas, also known as flow diversity
- Steep edges, shallow bank zones and gravel banks
Important individual measures are
- Reactivation of floodplains
- the connection of tributaries
- the installation of boulders
- the restoration and creation of riparian strips
- Creating continuity for living organisms by, for example, redesigning obstacles to migration or bank and bed stabilization
- redesigning ponds: Inflow/outflow into the tributary
Some projects have already been successfully implemented. Following its renaturation, the Wickerbach at Obermühle has a structurally rich bed, shallow banks and dense, natural vegetation. Not only the creatures in the water but also species outside the water benefit from a good ecological status. For example, amphibians, insects, birds and bats.
What difficulties are there in implementing the Water Framework Directive in Wiesbaden?
Outside of built-up areas, the aim is for watercourses to develop naturally. Targeted measures such as the installation of dead wood or planting allow the watercourse to find its own way. This often leads to a conflict of interest because the area required for such measures is not available. Agricultural use, allotments or private garden plots are located within the legally prescribed ten-metre watercourse edge strip. As a result, natural watercourse development can only take place in a limited area.
In many places, it is not so easy to restore near-natural structures in urban areas. The solution is so-called stepping stone biotopes. These are intended to connect larger habitats that are further apart, enabling an exchange between isolated groups. In order to enable organisms to migrate between these biotopes, the river bed is made continuous by means of structural improvement measures. It is important to ensure that the implementation of these measures does not worsen the discharge situation.
How is the Water Framework Directive progressing in Wiesbaden?
Those responsible for watercourse maintenance are responsible for implementing measures. This is extensively funded by the state of Hesse. Some measures have already been implemented, others are being implemented or planned.