landward. At larger distances from the foredunes ([500 m) additional measures to
maintain biodiversity will remain necessary for the coming decades (if there is a
continued call for increased biodiversity).
Nourishments can be adapted to meet restoration needs. For example, nourishment could be started after a few years of foredune breaching, releasing the
sand, and providing possibilities for landward transfer. Then, some extra amounts
of sand could be nourished to feed the dune system. In the past, coastal defense
engineers considered any landward transport of sand as a loss for the defense
system. Nowadays, with sea level rise, any input of sediment into our country
should be regarded as a welcome aid to keep our heads above the water.
7.8 Costs of Restoration Projects
The costs of the restoration projects largely depend on the specific situation. In the
Dutch coastal dunes the costs usually imply:
1. Geomorphological research and engineering.
2. Archeological research (to prevent damage to archeological heritage).
3. Removal of explosives from World War 2.
4. Removal of soil; the depth of removal depends on the depth of soil development (presence of organic matter). Usually, all soil containing organic matter is
removed.
5. Removal of vegetation; the type of vegetation determines the efforts needed.
The costs of removing a forest (cutting of trees, removal of the stubs) are higher
than those incurred in removing a grass land (except when the wood can be
sold).
6. Communication to create local support.
Often, the costs of the transportation of soil and sand are the most expensive,
depending on local infrastructure, transport distance, and marketing possibilities.
For example, if the sand can be sold for other purposes, transport is often free, and
the project may even be completely financed by the profits. This was the case in
the Verlaten Veld, where the sand was used for construction of a noise barrier
around the racing circuit of Zandvoort. Another option is the use of sand for other
nature restoration projects, for example, filling in former excavations, which was
the case with the Bruid of Haarlem. In foredune projects, the sand is usually not
removed from the site, but spread over the beach and dunefoot. Then, the costs are
limited to the hiring of the equipment. Of course, the costs depend on the scale of
the project. For remobilization projects the average depth of soil and sand removal
is about 0.3 m, which means that per hectare about 3,000 m
3 have to be removed
(price approximately 2–8 €/m
3 ). However, this depends on the present vegetation.
In the case of the dominance of marram grass, the removal depth increases to up to
1 m, in order to get rid of most of the roots. This increases the costs enormously.
An alternative is to manually remove the roots from the area for a number of years.
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121
maintain biodiversity will remain necessary for the coming decades (if there is a
continued call for increased biodiversity).
Nourishments can be adapted to meet restoration needs. For example, nourishment could be started after a few years of foredune breaching, releasing the
sand, and providing possibilities for landward transfer. Then, some extra amounts
of sand could be nourished to feed the dune system. In the past, coastal defense
engineers considered any landward transport of sand as a loss for the defense
system. Nowadays, with sea level rise, any input of sediment into our country
should be regarded as a welcome aid to keep our heads above the water.
7.8 Costs of Restoration Projects
The costs of the restoration projects largely depend on the specific situation. In the
Dutch coastal dunes the costs usually imply:
1. Geomorphological research and engineering.
2. Archeological research (to prevent damage to archeological heritage).
3. Removal of explosives from World War 2.
4. Removal of soil; the depth of removal depends on the depth of soil development (presence of organic matter). Usually, all soil containing organic matter is
removed.
5. Removal of vegetation; the type of vegetation determines the efforts needed.
The costs of removing a forest (cutting of trees, removal of the stubs) are higher
than those incurred in removing a grass land (except when the wood can be
sold).
6. Communication to create local support.
Often, the costs of the transportation of soil and sand are the most expensive,
depending on local infrastructure, transport distance, and marketing possibilities.
For example, if the sand can be sold for other purposes, transport is often free, and
the project may even be completely financed by the profits. This was the case in
the Verlaten Veld, where the sand was used for construction of a noise barrier
around the racing circuit of Zandvoort. Another option is the use of sand for other
nature restoration projects, for example, filling in former excavations, which was
the case with the Bruid of Haarlem. In foredune projects, the sand is usually not
removed from the site, but spread over the beach and dunefoot. Then, the costs are
limited to the hiring of the equipment. Of course, the costs depend on the scale of
the project. For remobilization projects the average depth of soil and sand removal
is about 0.3 m, which means that per hectare about 3,000 m
3 have to be removed
(price approximately 2–8 €/m
3 ). However, this depends on the present vegetation.
In the case of the dominance of marram grass, the removal depth increases to up to
1 m, in order to get rid of most of the roots. This increases the costs enormously.
An alternative is to manually remove the roots from the area for a number of years.
7 Restoration of Dune Mobility in The Netherlands
121