Vulnerabilities - The Netherlands

What are ‘water shortages’?

In the Netherlands, water shortages are defined as the difference between supply and demand of water of sufficiently good quality. Water shortages may result from a high precipitation deficit, low river discharge, lack of (infrastructural) possibilities to redistribute the water, and a deteriorating water quality (including salinization and higher water temperatures) (1).

The precipitation deficit is defined as the maximum cumulative difference between precipitation and evaporation between April 1 and October 1. The average precipitation deficit is 151 mm. Extreme precipitation deficits (as occurred in 1911, 1921, 1959 en 1976) are over 300 mm. Even though the summer of 2003 was extremely hot, the precipitation deficit was relatively modest (220 mm). No trend has been observed in the yearly maximum cumulative precipitation deficit over the last 100 years (1).

Present supply and demand

Water supply in an average year is about 3000 mm. In the extremely dry year of 1976 it was 40% less. About 60% of the fresh water supply in the Netherlands comes from the river Rhine, 30% is precipitation and 10% stems from other rivers. On a yearly basis,60 to 80% of the river supply is discharged into the sea, depending on the drought conditions of the year. Even though this water is not used for agriculture f.i., it has a function though: to avoid salt intrusion in the river outlets, and to maintain a sufficiently deep navigation channel in the rivers (1).

Future supply and demand

Different climate change scenarios show different impacts on future water shortages. Two extreme scenario’s have been analyzed with respect to future droughts in the Netherlands. A scenario with modest climate change indicates that water shortages in 2050 may be quite similar to the present situation. A scenario in which the climate changes fast shows a 16% increase of evaporation and a 20% reduction of precipitation in the summer; this change may be twice as large in 2100 (2). An increase of water shortage in dry summers seems likely in the next 50 years. Low river discharge in dry summers will probably also reduce; for the Rhine a significant reduction is expected only after 2050, however (10).

Vulnerabilities – Stability of flood defences

A lot of the dikes near canals and lakes in the low-lying parts of the Netherlands are made out of peat. These dikes were constructed in the course of hundreds of years. During the dry summer of 2003 one of the dikes burst, and several houses behind the dikes were flooded. It appeared that the drying-out of peat dikes makes them too light and unstable to withstand the force of the water. Therefore, the water level in the canals and lakes near these dikes needs to be kept sufficiently high in order to avoid drying-out of  these dikes (1).

Vulnerabilities - Agriculture

In dry summers production losses in agriculture result from the crops not being able to evaporate the amount of water that is needed for optimum growth. This is due to the fact that sprinkling facilities are not designed for these conditions and the withdrawal of groundwater for irrigation in dry summers is strictly regulated. Besides, the sprinkling capacity in especially the western part of the country cannot be used fully when the surface water becomes too salt, which is the case when there is not sufficiently fresh (river) water available to wash down the seepage of salt water in the low-lying polders. In effect, in dry summers water with a relatively high salt concentration is let in into the ditches in order to maintain the water level in peat areas (1).

Vulnerabilities – Nature

Aquatic ecosystems may be affected by low oxygen levels, high salt concentration and water temperature, too little dilution of pollution, and the risk of botulism and toxic cyanobacteria. Terrestrial ecosystems may be affected by low ground water levels. In the Netherlands, (terrestrial) ecosystems are vulnerable to droughts because they are adapted to man-made conditions. Under more natural conditions the impact of droughts to ecosystems would be less than the present situation (1).

Vulnerabilities – Shipping

In the Netherlands, inland shipping contributes about 30% to the total transport of goods. At low Rhine and Meuse river discharge shipping is hindered because ships cannot be loaded to their full extent. More passages are needed to transport the same volume of goods and ships have to wait longer at sluices because of higher navigation intensity. All of this results in higher economic costs for society as a whole (1). Probably, problems due to the navigation channel being too shallow will occur on the German Rhine first before they are a fact in the Netherlands (2).

Vulnerabilities – Cooling water for power plants

Over the last 100 years, river water temperature has risen by 3⁰C in the Netherlands, and temperature will continue to rise by another 1-3⁰C until 2050. Sometimes in dry summers, the amount of water needed to cool power plants is insufficient because, for ecological reasons, there are restrictions with respect to the temperature of the water that power plants are allowed to discharge into the rivers (1).

Vulnerabilities – Drinking water

At a number of locations drinking water is extracted from surface water. Basins for drinking water have been built to avoid shortages of water of good quality, which might happen during low river discharge. The size of these basins is such that a shortage of drinking water during dry summers is extremely unlikely in the Netherlands (1). The industry will become less dependent on groundwater or surface water because of an increase of the use of technology for water recycling (2).

Vulnerabilities – Recreation

Water shortages in the lakes and canals may affect the quality of the water for swimming, the navigability (too shallow), the quality of the fish stock, and the waiting time near sluices (1).

Vulnerabilities – Urban areas

In urban areas fresh water is needed to wash down the water in the canals and maintain water of a sufficiently high quality. Besides, the water level in urban areas needs to be maintained to avoid instabilities of foundations (1). It is estimated that the foundations of about 140,000 houses in the Netherlands suffer from low groundwater tables (8) and that about one third of the historic buildings in the country are vulnerable for droughts (9).

Sinking ground water levels damage the foundation of buildings. Too low ground water levels have already caused over € 5 billion of damage to foundations and buildings. During this century this may increase up to a total amount of € 40 billion is no measures are taken to stop this (17).

Vulnerabilities – Infrastructure

Droughts may result in damage to infrastructure through low groundwater tables. Railways and roads may subside, sewage pipes and cables may break, and wooden foundations may rot when exposed to the air (2).

Estimates drought risk in 2050

The current drought risk in the Netherlands (year of reference 2022) is estimated at EUR 372 million per year and may increase to 607 - 611 million per year until 2050 according to a worst-case scenario of climate change. Under a moderate scenario of climate change, the drought risk in 2050 is estimated to remain similar to the current situation. This drought risk includes the impacts on shipping, drinking water, industry, and agriculture. Also, estimates of drought impacts on soil subsidence, instability of peat embankments, water quality, and biodiversity loss were included. Drought impacts on recreation and urban green spaces were not monetized because the impact was considered relatively small, or these were not expected to be affected by policy actions. Limitations in cooling water availability are not expected and therefore not taken into account (18).

Adaptation strategies - EU

EU policy orientations for future action

According to the EU, policy orientations for the way forward are (15):

• Putting the right price tag on water;
• Allocating water and water-related funding more efficiently: Improving land-use planning, and Financing water efficiency;
• Improving drought risk management: Developing drought risk management plans, Developing an observatory and an early warning system on droughts, and Further optimising the use of the EU Solidarity Fund and European Mechanism for Civil Protection;
• Considering additional water supply infrastructures;
• Fostering water efficient technologies and practices;
• Fostering the emergence of a water-saving culture in Europe;
• Improve knowledge and data collection: A water scarcity and drought information system throughout Europe, and Research and technological development opportunities.

Water managers need to consider water shortages in the plans for the future. In The Netherlands, a guideline has been developed to help water managers to do so (6).

Several adaptation strategies can be adapted to reduce the impact of droughts: strategies to reduce water demand, to use water more efficiently, or to increase water availability. 

Adaptation strategies – Water demand

Citizens can be stimulated to use water more efficiently by raising their awareness about the amount of water that is needed to produce the goods they use or the food they consume (the so-called water footprints). Also, serious games can be used to visualize water management issues related to, for instance, droughts (11).

Adaptation strategies - Agriculture

The impact of water shortages is highest for agriculture and nature, and small to negligible for the other interests. Measures to improve water supply for agriculture, and that may be beneficial in terms of costs and benefits, are enlarging water storage facilities, creating more facilities for sprinkling, and several small scale measures (1). An innovative technique for more efficient water use in agriculture is real time monitoring of the moisture content of the soil in connection with a decision support system for irrigation (11).

Adaptation strategies - Nature

Supplying water from one area to another may help agriculture. It may not be a good solution for drought in nature areas, however, since the quality of that water may not suit the specific conditions of nature. For nature, measures should be designed that make nature areas more robust with respect to droughts. Measures to overcome the impact of droughts for especially nature areas may be extremely expensive (billions of Euros) (1).

Adaptation strategies - Stability of flood defences

Currently, the stability of flood defences is the number one priority for fresh water supply in the Netherlands and policy is such that there will not be a shortage of water to secure the dikes. This will not change in the future. Measures for additional water supply, therefore, are not needed (1).

Adaptation strategies - Cooling water power plants

The amount of water needed to cool power plants in dry summers cannot be increased by water management measures. Instead, in the future locations near the coast may be preferred for new power plants whereas old power plants near the rivers may be shut down (1), and alternative cooling capacity such as cooling towers may build (2).   

Adaptation strategies – Drinking water

The water shortages for drinking water supply are negligible and no additional measures need to be taken (1).

Adaptation strategies - Shipping

The vulnerabilities of shipping for the consequences of climate change cannot be overcome by large-scale infrastructural measures cost-effectively. The best option is to use smaller vessels or to transport less load.

At present, there is no need to take measures for shipping in view of the consequences of climate change. If the climate appears to change faster than current projections indicate, adequate measures can still be taken in time (1).

Some promising solutions for the consequences of climate change for inland navigation are (13):

Adaptation strategies - Recreation

The volumes of water that are needed to prevent botulism and toxic cyanabacteria cannot yet be quantified. A qualitative assessment has shown that adequate measures at most of the critical locations in the Netherlands are hardly possible from a technical point of view (1).

Adaptation strategies – Combating salt intrusion

The intrusion of salt water near sluices can be restricted by using bubbles of air that separate fresh water from salt water. These techniques are already used near several sluices in the Netherlands (11). The intrusion of salt groundwater can be restricted by infiltrating fresh water into the subsoil that acts as a hydraulic barrier against penetrating seawater. This innovative technique is already used in Barcelona since 2007 (12).

Adaptation strategies - Priorities in water supply during droughts

During droughts in the Netherlands there is not enough fresh water of sufficiently good quality to supply all the interests at stake with the amounts of fresh water they need to function optimally. The interests are prioritized, therefore, in the order of importance/vulnerability so as to make sure that the water supply for the most critical/vulnerable interests are secured. The prioritization in order of decreasing vulnerability is shown below (7):

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for the Netherlands.

1. Ministry of Transport, Public Works and Water Management (2005a)
2. Deltares (2011)
3. LEI (2003), in: Ministry of Transport, Public Works and Water Management (2005a).
4. CPB (1996), in: Ministry of Transport, Public Works and Water Management (2005a)
5. RIZA (2004), in: Ministry of Transport, Public Works and Water Management (2005a)
6. www.droogtestudie.nl
7. Ministry of Transport, Public Works and Water Management (2009)
8. KMPG/Grontmij (2001), in: Deltares (2011)
9. Deltares (2010), in: Deltares (2011)
10. Görgen et al. (2010)
11. Deltares (2011)
12. Teijón et al. (2009) in: Deltares (2011)
13. Krekt et al. (2011)
14. Ministry of Transport, Public Works and Water Management (2005b)
15. Commission of the European Communities (2007)
16. Bergsma et al. (2008)
17. Ministry of Infrastructure and the Environment, and Ministry of Economic Affairs, Agriculture and Innovation (2012)
18. Mens et al. (2022)