Dijkgraaf: "Living safely with water is becoming less self-evident"

KNMI climate scenarios

Periods of flooding and prolonged drought are increasing, according to the KNMI. The guarantee of sufficient fresh water supply when it is too dry and sufficient water drainage when it is too wet is coming under further pressure. "Living safely with water is no longer as self-evident as it used to be," says Roeland van der Schaaf, dike reeve of the Noorderzijlvest Water Authority.

New forms of coastal defense

The water boards use the climate scenarios to establish standards for water safety, flooding, and drought. In its response to the climate scenarios, the Union of Water Boards advocates the urgency of continuing to reinforce dikes and reserving sufficient space and funds for this purpose. The dike reeve adds: "Reinforcement operations are taking place throughout the country; the largest intervention since the Delta Works. We must certainly continue with those plans. In our area, the sea dike is currently being reinforced along the Lauwersmeer-Vierhuizergat route." The dike reeve argues that in the near future, more will be needed than simply continuing to raise and widen the dikes. "Of course, this cannot go on indefinitely. There will not be enough space for this everywhere. That is why research is already being conducted throughout the country, and certainly in our region, into how coastal defense can be redesigned: with dike landscapes in a wide coastal zone in which, for example, the force of the sea is absorbed outside the dikes. Or where we need to move more with the sea in some places." 

The year 2100 is the new starting point

The water board as an institution has existed for centuries and ensures that we can continue to live in the delta. "We have already done a lot to reinforce the dikes, temporarily store excess water, and solve problems caused by soil subsidence. We will continue to do so. However, the outlook is even more threatening," says the dike reeve. According to Van der Schaaf, it is imperative that we base our plans on the outlook for 2100 outlined by the KNMI: "If we all think now about what will be needed by then to live safely with water here, we will have a better idea of the decisions we need to make now." The dike reeve believes it is very wise to already take into account a different spatial plan for a broad, safe coastal zone. "This requires a planning reservation and thorough consultation and coordination with the national government, the province, and municipalities," adds Van der Schaaf.

Important for safety in the region: discharge into the sea

For the northern Netherlands, the latest climate scenarios underscore the need to continue to be able to drain excess precipitation into the sea. Currently, this is still largely done by gravity from the high sandy soils in Drenthe through the lower-lying reservoir in Groningen via Lauwersmeer and the Cleveringsluizen sluices to the Wadden Sea. If the sea level rises by one meter, drainage by gravity will become virtually impossible.

"For water safety in our region, the construction of one or more large sea pumping stations is inevitable. This means that we are facing very substantial investments. The northern water boards certainly cannot bear these enormous investments alone," says the dike reeve.

Weighing up land use adjustments together

The days when technology solved everything are over. Van der Schaaf: "We need to rely more on natural values in our water system; fight less against the water and go with the flow more. Technology will continue to help us manage water. But completely eliminating risks is a thing of the past. We must accept drought and flooding to a certain extent and jointly consider what function the available space will serve and what adjustments to land use are desirable. From now on, land use will have to adapt more and more to water, soil, and the effects of climate change. This applies to all types of land use, such as construction, agriculture, and nature.

Space must be reserved at all levels.

In order to keep our landscape and water systems climate-resilient, more space and considerably more money are needed for adjustments to water management. That is why the water boards are advocating for these spatial reservations for water to be included in, among other things, the Spatial Planning Policy Document that the Ministry of the Interior is currently working on. Noorderzijlvest adds, through its dike reeve: "These spatial reservations must also be included in provincial and municipal environmental visions and associated regulations. This must also be done now, so as not to waste any time!"

Finally, the water authorities are calling for substantial additional funding for the Delta Fund so that our country will be better equipped to deal with the uncertainties associated with sea level rise.