The project

The presentation of the delta decisions and the delta plan in 2014 made arrangements for the freshwater supply in the Netherlands for the next few years. The measures are being implemented and we know what we have to do in the medium to long term. Having applied adaptive delta management, we know whether measures can be carried out sooner or later. We are able to adapt to climate change and/or undertake major interventions in our water system, such as installing a large new sea lock.

The national government, regions and users have also agreed that they want to increase transparency surrounding the availability of freshwater by 2021. After 2021, new or revised agreements on responsibilities and endeavours will be made between national government, the region and users. The aim is to achieve the optimum distribution and usage of the Dutch water system.

What did we do and what is the result?

In 2015, at the request of the Minister of Infrastructure and the Environment, we carried out a stress test. We have tested whether and for how long the preferred strategy for freshwater, as set out in the delta programme, will suffice. We considered the implications for the strategy of the negative consequences of climate change, combined with a growing demand for freshwater and a changing infrastructure. The findings showed that the Delta Plan for Freshwater is robust. Major interventions, such as building a large sea lock in IJmuiden and deepening the Nieuwe Waterweg ship canal, need not jeopardise the freshwater supply. It may be necessary to accelerate the pace of the adaptation pathway (which sets out the timetable for the measures). Where salination is concerned, recommendations have been made to elaborate on the adaptation plan for the West Netherlands.

In order to be adaptive, early detection is a must. So, at the request of the Directorate-General for Spatial Development and Water Affairs and Rijkswaterstaat, Deltares has taken the first step in designing an early warning system for the implementation of the freshwater strategy. We have, for example, carried out case studies to investigate the potential reliable indicators and/or thresholds for giving warning of a tipping point.

To provide a more reliable economic basis for decisions on measures and the distribution of water in 2021, last year Deltares, in partnership with Stratelligence and the Agricultural Economics Research Institute (LEI), developed an economic method. The cost-benefit analysis takes account of the varying degrees of drought in different years and the implications for each sector.

Judith ter Maat en Tom van der Wekken
To be adaptive, an early warning system is a must. Therefore, the first step has also been taken in designing an early warning system as part of the freshwater strategy.
Judith ter Maat
Expert in Water Resources & Delta Management, Deltares
Thanks to research by Deltares, we now have an even better understanding of the measures necessary to improve the availability of freshwater, now and in the future. This is essential to effective, adaptive delta management and transparent decision-making within the Freshwater Delta Programme.
Tom van der Wekken


In this project Deltares worked together with the following partners:

Would you like to know more about this project?
Judith ter Maat
Judith ter Maat
Expert water resources and delta management
+31 (0)88 335 8195
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Deltares Annual Report 2015