Two areas were restored: Groote Zaag and Eastern Balkengat. The executed work is in line with the Water Framework Directive (WFD), which is aimed at implementing measures that contribute to a good groundwater and surface water quality and sustainable use of water.
Project characteristics
Martens en Van Oord started this project on behalf of Rijkswaterstaat in March 2016. The project was completed in late 2017.
Measures for Groote Zaag
Nature restoration involves quite a lot. This also applies to the island De Zaag, where Martens en Van Oord took care of two subareas. Groote Zaag is a natural area in the western part. Bank defences were constructed over 300 metres along the Nieuwe Maas. Behind these, a system of creeks was created with a gradual transition from wet to dry. The new system of creeks is constantly flooded.
The currents and water levels in the creeks change due to the fresh water tides. The muddy banks are flooded during high tide and fall dry during low tide. This is a natural situation for the river delta. If offers the right conditions for fauna such as fish, birds and beavers, and flora such as cane, bulrush and reed. Limited shipping access protects flora and fauna in the fresh water tidal area.
Footpaths for management and walking have also been created here with a bridge over the new creek and various observation points. Access to the area has been made more friendly. Car parks, an access path, cycling facilities and a public garden have been developed.
Eastern Balkengat
The eastern Balkengat is a shallow zone behind a longitudinal dam, which is almost always flooded. On the side of the Bakkerskil, two groynes were constructed and the bay between the two dams was raised, allowing a river forest and a water zone to form. This new natural area is not accessible for recreation.
Modification of design
A lot of thought was put in before the start of this project. The water rises twice a day due to the tides. A sand embankment was created in order to transport equipment across the island. In addition, the design was modified to ensure that small vessels and barges could enter and leave the area via one of the creeks. This allowed excavated soil to be transported to the eastern Balkengat, where it was used to create new land.
Restoration of original natural areas
Due to the closing of major sea arms, many estuaries are no longer subject to tidal movements. This means that there is little exchange between the sea and rivers, and nature in areas such as the Zaag has become rare. Rijkswaterstaat is restoring the original natural areas to improve the quality of the water for plants and animals. Restoring the health of the water will eventually boost the quality of nature, the landscape and recreation.
Water Framework Directive (WFD)
The Water Framework Directive entered into force in late 2000. The WFD uses measures to ensure that the quality of groundwater and surface water in Europe is good and that we can use water sustainably. The ecological quality of most Dutch waters is not good enough due to interventions that have made the water less natural. Examples are steep and hard banks, weirs and dams, straightening of rivers, training of streams and the removal of gradual transitions. Most of the measures intended to achieve the WFD targets are therefore related to restoring and creating a natural living environment.
Corné supervised the entire process. Please contact him or let him know what he can do for you in the form below and he will call you back or email a reply.
