National Ecological Network and water retention
Large sections of the National Ecological Network - particularly in the lower-lying parts of the Netherlands - overlap with areas in which space is being sought for water retention.
Current situation
The Netherlands needs areas in which to retain surface water temporarily during periods of flooding. These areas have been broadly outlined - as "search areas" - by national government and by the provinces. They overlap with the National Ecological Network (Ecologische Hoofdstructuur, EHS), particularly in the lower-lying parts of the country. In the case of the major rivers, the extent of the overlap is 29 000 hectares and for regional rivers more than 80 000 hectares. This is approx. 15% of the EHS.
The combination of the EHS with water retention areas offers opportunities for wetlands and aquatic ecosystems. However, vulnerable nature areas that require nutrient-poor conditions will be adversely affected by surface water retention because the surface water contains too high a level of nutrients. Approximately 18 000 hectares of the overlap between the EHS and the regional "search areas" include vulnerable nature areas, but the unsuitable quality of the water can also be a problem outside these areas.
The "search areas" have been defined far more broadly than will ultimately be necessary. The water boards, provinces and municipalities will define the actual water retention areas more precisely at a later date.
Policy objectives
The "Nature for People, People for Nature" (Natuur voor mensen, mensen voor natuur) memorandum states that nature development within the EHS is compatible with water retention and that combining nature development with "space for water" can provide opportunities for creating new wetlands and aquatic ecosystems and wet ecological corridors, combating groundwater depletion, and increasing the natural quality of aquatic ecosystems.
