MASTER PLAN FOR COASTAL SAFETY

The Flemish Government approved the Master Plan for Coastal Safety in June 2011. That proposes a series of measures to protect our 67-kilometre-long coast against a 1000-year storm surge. In the same year the Coastal Division started already with the implementation of the measures.

In the Master Plan, all flood risks are established and the risk zones charted. For each risk zone, measures and possible alternatives are studied. The emphasis is primarily put on the realisation of the chosen measures necessary to ensure the coastal safety until 2050. Thereby the expected rise in sea level is being taken into consideration.

In addition to the implementation of the planned measures, it is important to follow closely coastal erosion and the effects of emerging storms. To that end, the Coastal Division has a plane flying over the beach twice a year and also over all dune areas once every three years. Using LiDAR technology (Light Detection And Ranging), height maps of the beaches and dunes are created. This way, the areas where erosion or sedimentation has occurred can be identified and further management can be planned. Since the foreshore (the underwater beach) plays an important role in coastal dynamics, this too is mapped.

To maintain the full sea defence structure so it continues to comply with the proposed level of security, the Coastal Division implements, amongst other, maintenance nourishments. Every six years, a test of the sea defence is made. The last test took place in 2017.  Read more about this here.

The measures of the Master Plan for Coastal Security do not only protect us against a 1000-year storm surge, but also against smaller storm surges. With storm surges bigger than a 1000-year storm surge, our coast is not fully protected but the impact will be smaller thanks to the measures taken.

Which measures were already implemented?

When implementing measures, the Coastal Division applies the principle " tough when needed, lenient when possible”. By carrying out nourishments along our sandy coast, we aim both for a safe as well as an attractive and natural coast.

NOURISHMENTS IN THE FRAMEWORK OF THE MASTER PLAN FOR COASTAL SAFETY

In the table below you will find the risk zones from the Master Plan Coastal Safety, along with the state of play of the implementation of the soft measures in the applicable zone. The indicated maintenance of risk zones covers both scheduled maintenance as well as repairs of heavy storm damage (e.g. after the Sinterklaas storm in 2013 or the Dieter storm in 2017).

Zone

Status

De Panne Centrum

Carrying out replenishment: 2011

Maintenance: 2017

Sint-Idesbald - Koksijde Centrum

Carrying out replenishment: 2011

Maintenance: 2017

Koksijde - Gilles Scottlaan Dune passage incremented and remade: 2013
Middelkerke - Westende

Carrying out replenishment: 2013 - 2015

Maintenance: 2017

Oostende - Mariakerke & Raversijde

Carrying out replenishment: 2014

Maintenance: 2018

Oostende Centrum

Carrying out replenishment: 2013

Maintenance: 2018

Oostende - Oosteroever Carrying out replenishment: 2014
De Haan - Wenduine

Carrying out replenishment: 2012

Maintenance: 2014, 2016, 2017, 2018

Blankenberge

Carrying out replenishment: 2014 - 2015 + use of dredged sand from harbour channel

Knokke-Heist prior to the planned replenishments in 2012, 2013, 2014, 2015 en 2017

In addition to the planned nourishments in the risk zones, in the period 2011-2018, several smaller nourishments were implemented in other locations on the coast in order to maintain in these locations, the robustness of the sea defence structure. In addition, the Coastal Division carries out yet another type of replenishment: the foreshore replenishment. In October 2017 such a replenishment was carried out in Nieuwpoort. Read more on that here. 

Sand replenishments are unmistakably one of the least environmentally harmful interventions in the context of sea defence structures and protection against flooding. The ecosystem is nonetheless temporarily affected by the applying of large volumes of sand on our beaches.

To limit as much as possible the potential impact and to promote as much as possible the repair of the marine environment, the Coastal Division commissioned a study that should allow the sand replenishments (or hydraulic-filling) to be carried out in as environmentally-friendly a manner as possible. The starting point in this regard is the so-called ecosystem approach, which leads to a complete and comprehensive understanding of beach ecology.

In addition, a monitoring programme was put together for large projects. By means of T0-monitoring (this is an examination of the ecology before any human interventions takes place) and T1, T2, T3 etc. monitoring (at regular intervals after the works), it is possible to determine the environmental impact of large projects shortly after the works and how the environmental recovery process is evolving. The works can then be adjusted where necessary (and if possible). More importantly, however, these samples and studies provide a lot of useful information for potential future projects and serve as input in assessing their environmental impact.

HARD SEA DEFENCE

In some places, protection through a wider and higher beach is inadequate. Therefore, in those places, additional measures are carried out with the construction of storm return walls, a wave damping development, a wider dike or a storm surge barrier.

2012: In Ostend, the Albert I promenade was reinforced across the full length and provided with a fully removable mobile storm surge barrier. Following the renovation of the sea dike promenade, a part of the historic bastion, the Zeeheldenplein at the level of the Klein Strand was completely renovated. Read more

2014:

  • On the Eastern Shore in Ostend the construction of storm return walls was launched. This project is being implemented in stages. The further realisation of storm return walls around the docks will be addressed in stages too. Read more
  • In September, the Coastal Division started the demolition and reconstruction of the sea dike in Wenduine. The new dike is structurally stronger and locally three to ten metres wider. By building two storm return walls on the dike, a 'stilling wave basin' arose. The project was completed by the end of June 2015. Read more

2016:

  • In March the works for the extension of the Zwin started. The most famous nature reserve gets 120 more hectares of nature reserve. It will be surrounded by a new dike. This dike should protect our coastal area and the hinterland of West-Flanders and Zeeland protect against storm surges from the sea. Read more
  • The Marina of Blankenberge is one of the weak links along our coast. That is why in September 2016 the Coastal Division started working around the port in order to protect the city. Together with the city of Blankenberge an architectural storm return wall is built around the port. Combined with a renewal of the area around the marina Blankenberge gets as such a safer but also classier and greener port. Read more.  

2018: In spring the Coastal Division starts with the construction of a storm surge barrier in the harbour channel of Nieuwpoort. This should protect the city and the hinterland against high water levels during heavy storms. The work will take morethan three years. Read more.  

 

What does the future hold?

Also in the future, the Coastal Division will continue to work on a safe shore. The projects below are fully in the preparation phase.

  • Mariakerke-Raversijde: End 2018, the Coastal Division will start with the implementation of the flood measures on the dike from Mariakerke to Raversijde. In some areas there will be a storm return wall and in some areas the dike will be wider. In addition, the creation of a dune landscape before the dike will tackle the problems caused by blowing sand on the tram tracks and the coastal road. The renovation of the outdated parts of the dike will create an added value for residents and recreationists.
  • In Middelkerke the sea dike gets a radical transformation. The entire dike is laid out again and gets a new format. Between the dike and the beach in the green zones there will be dunes again which will serve as buffer in extreme weather conditions. Therefore, hard structures will be less deployed. Read more
  • In the port of Zeebrugge, from the Visartsluis to the New Yorklaan and from the Vandammesluis to the Zweedse kaai, a storm return wall will be constructed. At the same time the bicycle path will be renewed. The implementation of these works will start in 2019.
  • There is a study in preparation for the assessment of the locks and dams along the coast.