Maintenance of dykes and flood embankments

We maintain dykes and flood embankments so that they remain strong enough to hold back water. Every six years, we test whether the dykes and flood embankments are still strong enough. This allows us to identify which sections need attention in good time.
We are responsible for the 70-kilometre-long sea dyke between Lauwersoog and Delfzijl. Behind the coast lie many rivers, creeks, small canals, ditches, canals, and waterways. Alongside all that water, there are also 450 kilometres of dykes and flood embankments. We take care of these together with owners and site managers.

When we plan maintenance on our dykes and flood embankments, we primarily consider:

  • Water in which boats sail. The flow and waves caused by boats cause wear and tear to the dykes, flood embankments, and quays. 
  • Places where the impact of gas extraction is noticeable. Gas extraction causes the ground to sink. This can have consequences for the height and strength of dykes and flood embankments. 
  • Dykes and flood embankments where people and animals walk.

Private owners

The water authority is not the only owner of dykes and flood embankments. Some parts are privately owned. For example, if someone lives next to a dyke. Or if there is a stream with a dam in a pasture.

Private owners ensure that there are no buildings, fences, loose items, or cars on the dykes. Trees and shrubs do nog belong on dykes. Root growth can reduce stability. The water authority expects owners to mow the grass and reseed bare patches. Any sheet piling made of wood or concrete is also maintained by the owner. Sheet piling stops the waterfront from collapsing.

Annual flood-embankment inspection in March

The water authority checks whether private individuals are maintaining these dykes and flood embankments properly. We do this every year in March with a flood-embankment inspection. If a dyke or flood embankment has not been maintained properly, we agree that this will be done. We then arrange a second inspection.

  • The water authority is not liable for damage to dykes caused by third parties.
  • If you see cracks in the dyke yourself, please contact the water authority.

Major work on sea dykes

Due to climate change and rising sea levels, our sea dykes must comply with new standards. Another major sea dyke reinforcement is on the agenda for the coming years: the reinforcement of the lake Lauwersmeer-Vierhuizergat dyke. In addition to reinforcing the dyke, we are also working on an innovative project. We are doing this together with the province of Groningen and it is called: the Double Dyke. In recent years, the dyke has been reinforced. This dyke now meets the standard again.

  • Reinforcement of the dyke

  • Double Dyke

  • Dyke improvement Eemshaven - Delfzijl

Reinforcement of the dyke

Due to climate change and rising sea levels, our sea dykes must comply with new standards. That is why the Eemshaven-Delfzijl dyke has been reinforced in recent years. This dyke now meets the standard again. Another major reinforcement of a sea dyke is on the agenda for the coming years: the reinforcement of the lake Lauwersmeer-Vierhuizergat dyke.

The Lauwersmeer dyke in Groningen is located between Lauwersoog and the Westpolder. This dyke no longer meets dyke-safety requirements. That is why dyke needs to be reinforced. This will ensure that we are well protected against flooding in the future.

Lauwersmeerdijk.noorderzijlvest.nl (Dutch only)

Double Dyke

We are also working on an innovative project. We are doing this together with the Groningen provincial executive, and it is called: the Dubbele Dijk (Double Dyke).

The Dubbele Dijk (double dyke) at Hoogwatum behind Bierum consists of a higher dyke at the waterfront and a lower dyke land inward. The two dykes together protect us from high water. This second dyke at the Bierummer beach is good for our safety, but also for nature, agriculture, and recreation. Between the two dykes will be an area with high tide and low tide. For this purpose, a culvert will be constructed in the sea dyke. The silty, salty water from the Eems-Dollard flows in and out of the area in between. The silt that flows with the water can settle there. As a result, the low-lying southern part slowly grows along with the rise in sea level. This creates a new area for plants and animals that thrive in brackish water. The northern part will offer space for innovative agriculture. There will be an area between the dykes where we will cultivate shrimp and seaweed. We will also grow plants that are more resistant to salt. Trials are being conducted with certain potato varieties, beans, and grains. Agricultural land is becoming increasingly salty due to the effects of climate change. We are studying the options for when this land is no longer suitable for traditional agriculture.

More information

Dyke improvement Eemshaven - Delfzijl

At the end of 2019, the Eemshaven-Delfzijl dyke was officially declared 'dyke-safe' and earthquake-proof for the next 25 years. The sea dyke is the first in our country to be reinforced in accordance with the latest safety standards and earthquake measures.

Between Eemshaven and Delfzijl lies a sea dyke of 11.7 kilometres. This sea dyke no longer complied with all the standards. The reason: climate change and gas extraction in Groningen. That is why we have improved and reinforced the sea dyke. 

Dyke improvement in 360 degrees

From 2017 to the end of 2019, we worked on the dyke between Eemshaven and Delfzijl. We made the dyke higher, wider, and stronger. At the same time, we carried out a few other special projects for people and nature. In this video, you can experience the dyke improvement up close in 360 degrees.