Making the Markermeer and IJmeer lakes More Natural

The More Natural Markermeer-IJmeer research programme (NMIJ) looks at which measures are effective in restoring and strengthening the ecosystem in the Markermeer lake. It is located in, among other places, a unique aquatic testing ground, where full-scale trials are being conducted. The programme is being implemented for Rijkswaterstaat by a consortium consisting of Royal HaskoningDHV and Deltares. Deltares is teaming up with Royal HaskoningDHV to group together all the knowledge from this programme using a knowledge tool, and to draft practical recommendations. The aim is to create a high-quality living environment in the Markermeer-IJmeer area with appealing nature and leisure areas. The knowledge generated by the research can be used directly on other projects where eco-engineering plays a role.


Improving the ecosystem

At one time, there were plans to transform the Markermeer lake into a polder. The government finally decided against this plan in 2007. In 2009, the lake was designated as a Natura 2000 area. It emerged at that point that the ecosystem had degenerated in the meantime, with biodiversity being negatively affected. For example, populations of water birds eating fish and mussels had declined sharply. Deltares teamed up with a number of partners to look at the underlying causes in the Autonomous Downward Trends(ANT) study. In the NMIJ programme, practical trials were set up on the basis of the resultant findings to determine how the ecosystem can be improved and made future-robust. The field experiments have been allocated to three themes:

  • reducing sludge levels;
  • enhancing diversity;
  • linking ecosystems.

Aquatic testing ground

Aquatic testing ground experiments were established as a part of the NMIJ programme in the Markermeer on instructions from Rijkswaterstaat. These full-scale experiments involve a range of commercial and other parties, including Deltares, who are looking to see which measures are feasible, effective and affordable. Accordingly, an artificial reef, a swamp and reed banks have been created. The results of all the experiments are being combined with model studies, desk studies and the monitoring of other existing situations. All the data and recommendations will be included in a widely-available knowledge tool and also in fact sheets. On that basis, it will be possible to advise interventions that have a proven track record, leading to cost savings in the long term. In addition, the activities in the aquatic testing ground are demonstrating the impact of eco-engineering in practice. This enhances support for these interventions.