Room for the River for Flood Safely, Deventer, The Netherlands

The Netherlands has a long history of water management and flood protection. During the early and mid-90’s, water levels along major Dutch rivers were dangerously high and thousands of people and animals had to be evacuated. The solution was to create more room for the major rivers, bringing water management and spatial planning together to find an inclusive and effective long-term solution. This has been applied, among others, to the river IJssel running near the historic city of Deventer. The area has experienced high river water levels and flooding of the surrounding inhabited land as a result of decreased floodplain size and increased heavy rainfall. In order to reduce the chance of flooding, the river water in the IJssel needed to be to drained towards the lake IJssel more rapidly. This was done by employing various measures depending on the location along the river. The lowering of the flood plains included dredging and redesign of 10 kilometres of flood plains and the construction of a 100 meters wide channel over the full length of the area. This resulted in a reduction of water levels by 10 - 19 centimetres during high water. Next to these measures, new channels gave the IJssel more room to hold high water. The city took advantage of the opportunity these necessary measures presented to improve the spatial quality of the area, with the city’s historic character as a source of inspiration. The dynamics of fluctuating water levels has created a natural river habitat that increases biodiversity. The ecological ‘water farm’ was introduced to keep the vegetation in the flood plains low enough by grazing cattle to drain river water quickly to the sea during times of high water. Recreational users are able to make use of the area via hiking, biking, and water sports. The Deventer project is a part of a larger set of more than 30 projects along major Dutch rivers. It is an excellent example of how we in the Netherlands work to make our river areas safer but also more attractive.