The government has set up the Delta Programme to prepare our country for the impact of climate change. The Rhine needs to be able to discharge increasingly large volumes of water. In order to minimise the risk of flooding, rivers are being given more room and dykes are being improved.
The areas around the major rivers currently have the highest flood risk in the Netherlands. A flood could cause large numbers of casualties and significant social and economic losses. A higher protection level is therefore needed in virtually the entire rivers region. In addition, higher peak discharges can be expected in the long run, due to climate change, while in the tidal rivers area, the rising sea level is pushing up peak water levels.
Climate change could also increase the frequency of very low river water levels. This would cause problems for the shipping sector and would make it difficult to withdraw water from the river for, e.g., agricultural use. Moreover, the groundwater level may fall so far as to jeopardise the stability of the dykes.
Preferential strategy for the Rivers
The preferential strategy is the strategic roadmap for tackling the issues at play. The preferential strategy for the Rhine involves a powerful interaction between dyke improvement and river widening. Examples of river widening include: lowering floodplains, constructing secondary or flood channels, dyke relocation, and the use of retention areas. Dyke improvements are aimed at raising and/or strengthening the dykes.
The preferential strategy is geared to the characteristics of the river tributaries and seeks to link up with other interventions along the rivers, for example, for the natural environment, water quality or habitation. This map (in Dutch) shows the current measures and studies set down in the preferential strategy.
The Rhine Administrative Platform has developed promising river-widening measures for the Rhine tributaries as a whole, for the period up to approx. 2030. The measures make a substantial contribution to flood risk management, can be combined with other taskings in the area, and will be co-funded by the region. The measures are outlined in the Regional Proposal for the Rhine and the accompanying letter to the Minister.
In the autumn of 2015, the MIRT Consultation Committee decided to launch two explorations based on the Regional Proposal: one for the Varik Heesselt flood channel and one for the IJsselpoort River Climate Park.
Update of preferential strategy
River widening and dyke improvements are closely intertwined. For that reason, the Delta Programme intends to select and schedule long-term river-widening measures (beyond 2030) in interconnection with dyke improvements. The national and regional governments are working out a policy to this end, under the heading of Rivers Ambition.
Under the Rivers Ambition, the region will elaborate the river-widening opportunities for the Waal, the IJssel, and the bifurcation points area. With respect to the Nederrijn/Lek, the opportunities for river widening will be explored following the introduction of the new flood protection standards.
Preferential strategy for freshwater supply
Climate change may bring about longer periods of extremely low water levels in the Rhine. The Freshwater Supply preferential strategy focuses on “smart water management” in order to boost the possibilties for directing and utilising river water. This policy is being implemented at various locations, including in the weirs in the Nederrijn-Lek: near Driel, Amerongen, and Hagestein. In addition, the region will adapt the inlet points to smaller bodies of water, in order to allow in sufficient river water even if the water level in the rivers is low.
In the mid-term, greater water shortages may occur in Limburg. In that case, we have the option of transporting water from the Waal to the Meuse, for example via the Maas-Waal canal. In the years ahead, the Ministry of Infrastructure and the Environment will investigate whether or not this is advisable.
Pilots have been launched throughout the country in order to test out new methods for dealing with low water volumes. In the area around the major rivers, a pilot is being conducted to explore efficient irrigation techniques for high-quality crops. The Rivierenland district water board is conducting a study into the sustainable use of shallow groundwater.