Title: Soft sand engines Frisian IJsselmeer shore
The Delta Programme of the Netherlands Government is exploring a new national climate adaptation policy concerning flood protection and freshwater supply. This may include a gradual rise of the IJsselmeer lake level, along with the rising sealevel. At the same time, Atelier Fryslân (an initiative of the province to develop ideas to revitalise the Frisian landscape) is looking for possibilities to renew and revitalise the coastal landscape. The Frisian shore of the IJsselmeer is one of the focal points for renewal. These two initiatives opened a window of opportunity for innovations and experiments. In this context, the Building with Nature innovation programme was asked in 2009 by the national government (Ministry of Infrastructure and the Environment) to initiate a pilot study on this part of the Frisian coast.
Even though the idea of systematic gradual lake level rise is under dispute now, water levels are most likely to fluctuate more in the future and regional parties became aware of the urge to prepare for this. They also realised they had to increase their knowledge about the lake and its shores. Based on a definition study to investigate possibilities, and on discussions between the Ministry and regional actors, the decision was taken to initiate three small-scale shore nourishment (‘sand engine’) experiments.
View Pilot locations in a larger map
It was decided to explore the application of sand engines at three locations (see figure above), each focusing on different spatial functions. The first pilot, at Workumerwaard, aimed at revitalizing a nature area by inducing new sedimentation. The second, at Hindeloopen, was meant to enhance recreational beaches. And the third, at Oudemirdumerklif, concerns an experimental shallow foreshore to absorb wave energy as an alternative to dike strengthening.
Although the potential of creating semi-natural floodplains in the IJsselmeer is large, there is not much experience so far. Therefore, the general goal of the three experiments is to gain expertise in creating semi-natural floodplains along shallow lake shores and to fill knowledge gaps concerning sediment dynamics and the role of bioengineers in such low-dynamic areas. The experiments aim to find out whether sand nourishment is a good solution to create a more robust natural zone along the coast and to increase safety levels and natural and recreational values.
The objective is to gain knowledge and experience on the following processes and issues:
- The capacity of the system to transport sediment onshore.
- The contribution of littoral zone vegetation to trap sediment trapping.
- The adaptive capacity of the wetlands and shores
- The extent to which eco-dynamic coastal development can contribute to the interests of various sectors (safety, nature and recreation)
Concentrated offshore sand nourishments in a weakly dynamic environment like this will lead to a slow shoreward transport of part of the material, which gradually feeds sand to the shore. Pioneer vegetation (bioengineers) will settle on this newly deposited sediment, reduce erosion and trap new sediment, which helps to reduce the vulnerability of the nature areas outside the dike to flooding. This enables the establishment of a more robust natural system. As the vegetation will also function as a wave attenuator, this measure also contributes to coastal protection. Moreover, a coastline that is robust and diverse gains attractiveness to recreation.
The initiators of the experiments were aware of the challenge of dealing with conflicting interests. Especially the conflict of interest between the Ministry (favouring the policy of the lake level following the rising sea level) and provincial parties (opposing this policy) required careful manoeuvring in the initiation phase of the project.
Three levels of governance have to be taken into account when it comes to decision-making. First, there is the administrative arena, with the different levels of government – national, provincial and municipal. They all have authority and competences over the area and it takes time to align their different policies. Second, there are the experts from governmental and non-governmental organisations (NGO’s) and from private enterprises. They were brought together in a Community of Practice to discuss the options and to establish where more research was needed. Third, there is the local arena, with residents and other local stakeholders. In the case of Hindeloopen and Oudemirdumerklif this level proved to be very important to address.
A number of strategies proved helpful to take due account of these three levels. The first one is to keep the options for compromise sufficiently open by avoiding too sharp definitions and too strict appointments too early in the process. By keeping the initial concept open and vague, potential partners had the opportunity to bring their own interests into the design and to avoid early clashes and entrenching about the end result. The second strategy was to produce a short movie (as shown below) with decision makers expressing the importance of a Building with Nature approach for Fryslân. The movie is in Dutch and has Dutch subtitles as well, but it gives an idea of the concept.
Thirdly, actors in the area of the IJsselmeer were given a free choice to join the process. This is in contrast with most conventional projects, where actors use to be forced to participate as their values and interests are under pressure. Lastly, the pilots were framed as experiments, emphasizing that they were ‘allowed to fail’ without negative consequences for projects owners, experts, actors or stakeholders. This lowered the threshold to participate.
At the start only the Building with Nature consortium had a budget available, but this was not sufficient to cover the costs of the experiments. Together with the regional project partners a project plan was formulated and applications for subsidy resulted in successful acquisition of a total budget of € 2 million. Financial contributions were received from Building with Nature (see EcoShape), a subsidy from the climate buffer program (see climate buffers) and subsidies from the Province and the Water Board. A project team and a steering committee with local (municipalities), regional (It Fryske Gea, Water Board, province) and national (Rijkswaterstaat, Building with Nature, consultants) representatives was formed to manage the project and monitor expenditures. This broad financing underlines the broad acceptance of the approach. As each financier had specific objectives and wishes, it was decided to consider implementation of sand engines at three different locations: Hindeloopen, Workumerwaard and Oudemirdumerklif.