Pilot Investment Tongelreep Valley
in The Netherlands
Waterschap de Dommel, Internet: www.dommel.nl
Project leader: Marcel van Betuw
The Tongelreep is a tributary of the River Dommel and reaches from the Northern part of Belgium to the South of Eindhoven where it flows into the Dommel. The project area is located East of the village of Valkenswaard. In this part of the Tongelreep catchment area the Waterboard de Dommel, the local and regional governments, nature conservation organizations and land owners have agreed to invest in a sustainable environment. Consequently, they developed a programme for this specific region (“Gebieds-programma Tongelreep” (2000)) which implements an integrated approach with several aims and intentions. One of the integral projects that underline this program is the reconstruction of the Tongelreep. It is split up into three phases. The was the first phase of the total reconstruction was one of the nofdp pilot investments. The second and third phase are located up- and downstream and will be realsied soon.
Characteristic elements of the project area are several fish ponds (ca. 150 ha) along the Tongelreep. Most of them were constructed by man for breeding fish. The ponds are filled with water that is withdrawn from the Tongelreep. Because of their age of more than 100 years and many special plant and animal species, these fish ponds are representing a high cultural and natural value. The special species and habitats are protected by the EU-Habitat Directive (Natura2000). Since January 2002, the ponds are no longer exploited for fish breeding which makes further ecological development possible.
Downstream the project area near the River Dommel, 13 ha of urbanised land in the cities of Eindhoven and ‘s Hertogenbosch is suffering from floods at a frequency of once every 10 years. Partly, this situation is the result of the former canalization of brooks (i.e. the Tongelreep) and the increasing drainage of agricultural and urban areas. On the one hand the Tongelreep suffers from peak discharges and on the other hand the brook frequently runs dry during summers due to the withdrawal of water for supplying the fishponds. In particular the latter situation has a negative effect on the ecological development of the Tongelreep floodplain. Furthermore, poor water quality in the Tongelreep due to heavy metals and nutrients further restricts the good ecological development of the fish ponds.
Realised measures in this pilot investment are:
- The existing Tongelreep was filled up with sand in order to increase the level of the river bed;
- The old straightened stream was replaced by a new meandering course on a length of circa 8 km;
- Removal of some pond dikes along the brook in order to develop 15 ha of floodplain;
- The weir at “Drie Bruggen” has been automated and equipped with a fish ladder;
- Activation of 10 ha of retention area for water storage during high discharge periods;
- Construction of a helophyte filter covering a total area of 3 ha. This will improve the overall water quality;
- A bird observation tower and a boot-trail were installed;
- A new walking path is realized;
- Soil remediation along the brook has been achieved.
This pilot investment project has demonstrated how to consider hydrological aims and ecological / cultural historical values and how to deal with the EU-Habitat directive at the same time. Therefore, it is an integral project, in which we dealt with many sectoral aspects and stakeholders. Mostly agricultural surroundings are used to locate areas for water storage. By giving new functions to the former fish breeding ponds in terms of water storage the cultural and historical values of the total water system consisting of stream, supply canals and ponds can be maintained in a sustainable way.
