The Veluwe is the largest nature conservation area of the Netherlands. The area is rich in brooks and springs. Due to the growing build-up area and changing land use the old water management infrastructure no longer copes.
In early 1990’s, the traditional technical solution was replaced by a new integrated approach, which combines nature and landscape conservancy with modern water management. This brook restoration project primarily focused on the creation of extra water storage capacity in addition to the improvement of water quality, the re-establishment of cultural-historical values and the construction of pools and integration into the natural landscape.
Following the construction of retention basins, water no longer drains rapidly but is rather retained longer in the minor tributaries. This process was considered ideal due to the following factors.
The issue of standard norms for drainage not working well in sloping areas;
The area is of great natural and scenic value;
A result of higher government authorities adopting a policy for protection of wet natural areas and prevention of drainage;
The public resistance to the traditional unilateral approach to flooding.
The Veluwe Water Board introduced an integrated approach for the water system in order to prevent both flooding and dehydration within the basin. An impulse has been given to nature development through the construction of natural banks. Space was created along the brook for extra water storage capacity in the shape of natural, gradual banks which further included retention basins construction.
As regards the prevention of dehydration, the infiltration capacity in the area was improved which provided ideal conditions for seepage potential. These actions have resulted to policies that are in support of preventing floods in the basin following the good examples of increased storage capacity.
In addition, actions were also taken in several other smaller rivers that drain into Veluwe for instance, the Verloren Beek, one of the basins of the nine rivers that form Veluwe. To achieve a reduction in the peak discharge of the basin as mentioned before, a number of both natural and gradual retention banks were constructed in these basins.
Meanwhile in Epe (another river basin) excess water is temporarily retained in special locations called retention areas. Though the retention areas were initially intended to serve as a measure to correct the water balance in "Wetland Epe", an added value has been given to them by the creation of these areas in the most natural way possible and more important managing them as a new wet nature area. This was achieved by a means of prolonged retention of water in the basin, consequently reducing the peak discharge during periods of extreme precipitation.
Six retention basins with a total surface area of 6.2ha have been set up. In combination with the construction of collapsible culverts in the brook, it is now possible to use the various retention basins efficiently and the end result is an increase in the water storage capacity of the system by 30,000 m3. Apart from conserving and developing natural values in the area, the creation of extra storage capacity in the Eperbeken basin was one of the most important aspects of the realization of this initiative.
• Classical, traditional solutions do not always work in a changing, unique situation;
• Ensure getting support for the measures among the inhabitants is important;
• Combining water management functions with user functions for the inhabitants (skating, swimming, nature, playground) is important;
• Finding solutions in keeping with the scale of the problem, project phasing and clear appointments of tasks can help;
• Use the inhabitants’ knowledge / experience for the measures.
Importance of the case for IWRM
This case describes a new approach to an old problem; not solving a local flooding problem in the traditional, sectoral manner but rather with a broad, integrated approach. Conservancy of nature and landscape values and co-operation with the population in order to look at floods not only as a threat but also as an opportunity for broad rural development, nature restoration, recreation, “enrichment” of the habitat and for a new approach to water.
Management integration: international/ intergovernmental co-operation, trans-sectoral approach, user involvement, public private partnership, local governmentinvolvement, etc.
Photo credit: Filippo Diotalevi