Delta Programme IJsselmeer

The IJsselmeer Coast Delta Programme forms part of the national Delta Programme, in which the government is preparing the country for the consequences of climate change: a rising sea level, increased volume of the discharge from the rivers, more intensive downpours and longer periods of drought. All of these factors are combined in the IJsselmeer area.

Adapting the water levels to the new climate challenges of the IJsselmeer and Markermeer will have far-reaching consequences - both in a geographical sense and for other policy sectors - and depends on a number of others decisions taken elsewhere in the Netherlands.

To ensure that they are adequately prepared, the ministries involved commissioned our firm to conduct a wide-ranging study of the area and its future challenges. In the process we worked together with various specialists from different disciplines, such as hydrologists, and developed a strategy illustrated by clear visualizations and presentations.

One of the goals was to draw up an adaptive developmental strategy. Setting up a flexible water level management in the short term means that more fundamental choices can be postponed for a few decades. For instance, if a long period of drought is expected, the high summer level can be fixed earlier and allowed to rise up to ten centimetres above the present maximum. This flexibility marks a change from the present regime, in which the water is kept at a fixed summer and winter level as much as possible.

The projected development of the coast of Friesland gives an impression of the opportunities that may arise. This is focused on the 'soft sand engine’; the realization of sandy and reedy islands and flats a short distance from the mainland. This has ecological, landscape and recreational advantages: small harbours become permanently accessible, nests are washed away less frequently, dredging is required less, and vulnerable landscape features (such as drifting peat) are better protected.