Water availability bottlenecks in the French-Belgian Meuse catchment

This research was conducted as part of Floor Hermans’ graduation internship at WUR. The research was carried out in collaboration with RIWA-Maas and HKV Lijn in Water. This memorandum is a brief summary of Floor’s work.

Introduction

Water availability of the Maas River will decrease in the coming years. Due to climate change, the supply is decreasing, and due to economic development, the demand is increasing.

In 2020, Deltares conducted a bottleneck analysis of freshwater for RIWA-Maas using the KNMI’14 climate scenarios. This analysis was conducted using the RIBASIM model of the Meuse basin. The bottleneck analysis shows the locations in the Maas basin where the future water demand will be higher than the water supply during dry summer periods.

Recently, KNMI published the latest climate scenarios for the Netherlands, the KNMI’23 scenarios. The impact of these climate scenarios on water availability is still unknown. During her graduation internship, Floor Hermans updated Deltares’ research with the latest climate scenarios, focusing on developments in the French and Belgian parts of the Maas.

Research Objective

To identify future bottlenecks in water availability in the Meuse River basin by analyzing the effects of expected future climate change and socio-economic developments.

Key Findings

– The 10-day average annual minimum Maas discharge decreases in every climate scenario;

– The maximum discharge reduction is smaller than in the KNMI’14 scenarios;

– The spread in discharge reduction is smaller than in the KNMI’14 scenarios;

– The wet-dry climate projections mainly affect the number of future water availability bottlenecks, while emission scenarios affect the severity of future water availability bottlenecks;

– Bottlenecks are expected to increase in the future: less water will be available for the Netherlands!

Recommendations

Floor’s research shows that water availability in the Maas will decrease in the coming decades in France and Belgium. The Netherlands is located downstream and therefore depends on the decisions made in France and Belgium. The amount of water flowing into the Netherlands via the Maas at Borgharen will decrease due to climate change. Upstream decisions can further exacerbate this decrease.

Therefore, international cooperation in the Maas basin is recommended, as water availability in the Maas is not only a national issue. Besides recommending cooperation, further research into the following questions is also recommended:

– Is the current water management in the Netherlands adequate for the future?

– Should the focus be on managing upstream reservoirs or on measures within the Netherlands?