Six-year review

Under the Delta Programme, we are preparing for the future. We are gaining increasingly more knowledge of climate change, and the effects of measures are becoming increasingly manifest. At the same time, reality is constantly changing and generating new insights. That is why the Delta Decisions and Preferential Strategies are reviewed every six years. This enables a timely change of course if such is dictated. Delta Programme 2021 will comprise proposals for the review of the Delta Decisions and the regional Preferential Strategies as outlined in DP2015. The Delta Programme partners are developing such proposals step by step. Delta Programme 2020 provides the initial impetus.

Robust Delta Decisions, adaptive Preferential Strategies

The first six-year review commenced in mid-2018 and will be completed by the spring of 2020. The first results of the six-year review demonstrate that the Delta Decisions, as outlined in DP2015, are still robust. In May 2019, the Freshwater Administrative Platform agreed on the formulation of freshwater supply goals for 2050, analogous to those set down with respect to flood risk management and spatial adaptation. Optimum use will be made of the national goals as set down in DP2015. In the first six-year review in DP2021, the goals for 2050 will be incorporated into the Delta Decision on Freshwater Supply. Up to 2050, the Delta Decisions thus constitute the proper framework for rendering the Netherlands safe, climate-proof, and water-resilient. The Preferential Strategies set out in DP2015 feature an adaptive approach, which enables their adjustment if changing conditions so dictate. Adjustment will be called for in several respects. The Signal Group, the topic sections, and the region sections have taken stock of unforeseen developments and new insights. The steering groups and administrative consultation bodies have discussed potential adjustments.

Interim results and outline conclusions

The reviews of the analyses in the steering groups and administrative consultation bodies, up until now, have generated the following interim results and conclusions:

  • The 2014 Delta Scenarios have been fine-tuned in recent years, using new information from the Prosperity and Quality of the Environment scenarios and the “Paris agreement”. The conclusion is that in this first six-year review, minor revisions of the Delta Decisions and regional Preferential Strategies will suffice to accommodate new insights into climate change.
  • The perspectives of the future are still uncertain. For that reason, continued investments in research are imperative. In order to gain a better picture of the rate at which the sea level rise will develop in the longer run (beyond 2050), a Sea Level Rise Knowledge Programme will be initiated. The knowledge programme will also map out how a potential acceleration in sea level rise may impact our flood protection and freshwater supply.
  • Several climate-related developments, such as the occurrence of supercells, drought, and salinisation, are already manifesting, which was not foreseen in 2014. Such developments may constitute reason to revise and fine-tune regional Preferential Strategies and elements of Delta Decisions.
  • The impact of low water levels (such as low river discharges disrupting shipping traffic) also constitutes reason for potential revisions, in particular of the regional Preferential Strategies for the rivers Rhine and Meuse. Such revisions will be addressed in the Integrated River Management (IRM) programme.
  • New insights will also be used to fine-tune or concretise Delta Decisions and Preferential Strategies.

Not all the developments observed already dictate potential revisions. Some cases first require, e.g., further research in order to determine whether they actually involve a trend that calls for a revision of the Delta Decision or regional strategy. These types of developments will be re-considered during the second six-year review.

The potential revisions of the Delta Decisions and regional Preferential Strategies are set out in the pages pertaining to the topics of Flood Risk Management, Freshwater Supply, and Spatial Adaptation, and on the pages covering the regions: Rhine Estuary-Drechtsteden, Southwest Delta, IJsselmeer Region, River Rhine, River Meuse, Coast, and Wadden Region.

Delta Programme valuation survey

In 2013, the Delta Programme Commissioner commissioned Erasmus University Rotterdam to survey how the delta community valued the Delta Programme, which elements in the Delta Programme were perceived as valuable, and what the Delta Programme had produced. In 2018, another survey was conducted, aimed at enabling the delta community to weigh in on the first six-year review of the Delta Decisions and regional Preferential Strategies.