This part has an evaluation of the outcomes and limitations of the approaches and considers the topics of: policies for water related hazards (1), and the future of the Netherlands (2). The next part will contain two more topics.
1) First of all, in the Netherlands the policies and responsibilities for flood measures, both oceanic and fluvial, are well developed on a national level, but measures against the other increasingly alarming climate hazards of heat, drought, and heavy precipitation are much less developed. Measures against cascading events, involving e.g. health risks, are similarly less developed. This is proven by the detailed organizational charts and responsibilities for water quantity and quality from a European to a municipal level, which does not yet find its equal for the other hazards. A highlighted example is a new stress test for water quality, which does not get the same attention as water quantity, developed by the Foundation for applied research for water management (STOWA))[i]. A prudent approach would be to expand the current Delta Plan Spatial Adaptation to include these hazards and cascading impacts, rather than reinvent the wheel for each of these hazards. This would prevent duplicating governance networks and finance models for each separate hazard and allow for the streamlined implementation of measures. A similar challenge lies in international cooperation. This equally requires improvement, but due to the different nature of laws and policies in other neighboring countries, it is less easy to copy existing policies and organizational cooperation structures. Europe has seen an increase of over 60% of extreme weather events in the last three decades[ii]. From 2018, the Netherlands, western Germany, Belgium, and Luxembourg suffered from heatwaves and droughts, which was followed by a flood in 2021 with over 34 billion euros in damages[iii] and over 240 deaths[iv]. These type of the events, and the fact that the Netherlands is downstream of four rivers starting over a thousand kilometers abroad, traveling through four countries with each their own water management policies before it arrives at our borders, mean that greater cooperation of transboundary river basin management is required, which is why the Dutch Ministry of Water and Infrastructure have launched a new transboundary program to strengthen scientific and institutional collaboration and increasing collaborative capacity for floods and droughts. We already see this trend in response to the 2021 floods in Limburg and neighboring countries, when local stress tests were not sufficient to anticipate or respond to a regional level event, and now higher level stress tests are being developed[v]. On a more local level, the regional Dutch and German water boards are also cooperating on flood safety, prevention, drought, and water quality[vi]. On a larger scale, new policies will need to make a choice of which trend to follow for the possible future, including green infrastructure, and also need to address how to inform the Dutch public of the issues the country faces and why these decisions are being made.
2) The future of climate in the Netherlands is difficult to predict, but some trends will lead to inevitable impacts requiring the need for adaptive policies. Combined annual weather damages (see figure below) are heavily dependent on the number of storms hitting the country, and the subsequent deaths and number of cars subjected to water damage.
Figure: Annual weather damages in the Netherlands (based on Association of Insurers[vii])
While the current knowledge indicates the measures in the Delta program are sufficient until 2050, much like heat records, the sea level rise might also accelerate faster than anticipated. To address this for now hypothetical case, four major pathways[viii] are identified in how to deal with the most major challenges facing the West of the country. Up to 2050 about 600 billion euro worth of infrastructure investments are planned in the flood prone areas, with a life time expectation of 50-100 years, making it worthwhile to develop potential pathways of land use planning. The main consequences of sea level rise are not merely the threat to low lying land, but equally to drinking water access and agriculture, due to salt water intrusion. Based on the IPCC strategies of retreat, accommodate, and protect, the four scenarios for the Netherlands are illustrated in the image below. Protect means to conserve the current land use as much as possible, which requires increasing protective measures. It can be either to close off the connection to the ocean completely in the form of sluices, dams, and locks. It could also have a continuous open connection to the ocean, requiring all river harbors and levees inland to be strengthened. It also means inland waters become increasingly salinized. The third option of accommodate mirrors the living with water concept. This could take the form of locally raised grounds and ring levees. Due to increased flooding, millions of lives and livelihoods will be affected. Finally, in the option advance the coastline is extended into the ocean. This creates a new line of defense and would allow for the continuation of business as usual. It would allow for new land use development, but would cost 10-20 billion square meters of sand to create new land and have devastation ecological impacts.
Figure: Four possible scenarios for adapting to sea level rise in the province Zeeland[ix]
The main issue facing adaptation is that development and implementation of these types of policies takes decades, which might not be sufficient time to prepare for the changes experienced. It also calls for reserving areas that are also used for implementing plans with similar priorities: energy transition, housing, and infrastructure. This requires more coordination on a national level between ministries to align planning decades into the future.
The problem with future uncertainties is that these predicted worst case weather scenarios could happen in 2100, a2050, or tomorrow. While there is a prioritization to address the worst and most likely scenarios first, it still leaves much of the country insufficiently prepared, especially as the population still expects the government to prepare and manage everything.
[i] https://www.stowa.nl/sites/default/files/assets/PUBLICATIES/Publicaties%202023/STOWA-2023-38-Handreiking-stresstest-waterkwaliteit.pdf
[ii] https://www.sciencedirect.com/science/article/pii/S0341816223004691
[iii] https://www.sciencedirect.com/science/article/pii/S0921818124001887
[v] https://klimaatadaptatienederland.nl/actueel/actueel/nieuws/2024/handreiking-bovenregionale-stresstesten-gereed/
[vi] https://www.vechtstromen.nl/zoeken/@43020/gesprek-duitse/
[vii] https://www.nu.nl/binnenland/6360497/280-miljoen-euro-aan-weerschade-in-2024-veel-minder-dan-de-jaren-ervoor.html
[viii] Citation: van Alphen, J.; Haasnoot, M.; Diermanse, F. Uncertain Accelerated Sea-Level Rise, potential Consequences, and Adaptive Strategies in The Netherlands. Water 2022, 14, 1527. https://doi.org/10.3390/w14101527
[ix] DOI: 10.35248/2473-3350.24.27.640
