Drought
The concept of drought has several definitions, based on different criteria and impacts. Following the United Nations Office for Disaster Risk Reduction (UNDRR)(PDF), Global Facility for Disaster Reduction and Recovery (GFDRR)(PDF) and Britsch Geological Survey (BGS), the definitions are as follows:
- Meteorological drought is defined by prolonged periods of below average precipitation and/or above average evapotranspiration, relative to what is considered a normal or average amount for a given area, as well as by the duration of this dry period.
- Soil moisture drought focuses on lack of moisture in the layers that provide moisture for plant growth. It is caused by precipitation shortages and/or increased evapotranspiration, leading to soil water deficits and reduced groundwater availability. Soil moisture drought potentially impacts the agricultural sector; therefore, it is sometimes also called Agricultural drought.
- Hydrological drought refers to the impact of prolonged periods of reduced precipitation (including snowfall) and/or increased evapotranspiration on surface and subsurface water resources, such as river flows, reservoir and lake levels, and groundwater supplies. It encompasses various components, including groundwater drought, which specifically relates to sustained periods of below-average groundwater availability. The frequency and severity of hydrological droughts are typically assessed at the scale of a river basin, catchment area or groundwater body.
- Ecological drought refers to a prolonged and widespread shortage of naturally available water, resulting in excessively low groundwater levels and the drying up of natural streams, fens, and lakes. It includes changes in both natural and managed hydrological systems, placing multiple stresses on ecosystems. These stresses can lead to a wide range of impacts, including reduced plant productivity, dehydration of wildlife, shifts in species distributions, increased incidence of disease, declining water quality, and, in extreme cases, the extinction of vulnerable species.
Difference between drought, water stress, and water shortage
Drought is a natural phenomenon characterised by a prolonged period of below-average water availability and/or above-average evapotranspiration. In relation to drought, water stress refers to a condition where the demand for water exceeds the available supply of water with a good and sufficient quality, regardless of water availability levels. Water shortage refers to a temporary and acute condition that arises when water demand significantly exceeds the available supply due to a sudden reduction in water availability, typically triggered by a drought or other climatic extreme.
| Drought | Water stress | Water shortage |
|---|---|---|
| Short-term (weeks or months) | Long-term (structural) | Short-term (weeks or months) |
| Mainly natural (meteorological, hydrological), supply-driven | Anthropogenic, demand-driven | Combination of natural and anthropogenic factors |
| Low precipitation, high evapotranspiration, low river flows, low groundwater levels | Structural situation where water consumption is close to water availability | Imbalance between high water consumption and low availability, causing negative impacts |
Regional differences
Droughts and water stress vary locally in terms of intensity. The difference between low-lying and free draining, higher, areas is significant. In free draining regions, such as the areas with sandy soils in the central part, the east and the south of the Netherlands, water intake from rivers is either not possible or very limited. These areas rely primarily on precipitation and groundwater reserves for their water supply. Mainly during summer, low-lying areas are mostly dependent on water supply from surface water coming from our international rivers, the Rhine and the Meuse. Both rivers are bound to their catchment, concentrated at the south of the Netherlands, and reaching Lake IJssel via the IJssel River. Therefore, drought hotspots vary regionally from year to year. For a significant part of the year, water in low-lying areas is actually drained away by the major rivers.
Extensive water management systems in the low-lying part of the Netherlands are created which aim to distribute water to areas that have a water demand, including water to sustain sufficiently high groundwater levels. In most free draining areas this is not possible. As a result, these areas suffer more strongly from meteorological droughts, while in the low-lying areas it takes a combination of meteorological drought and low flows in Rhine and Meuse for problems to occur. The section Policies & regulations will further explain water management practices in the Netherlands.
Monitoring drought
To monitor drought, The Royal Netherlands Meteorological Institute (KNMI) calculates the potential net precipitation, also referred to as potential precipitation deficit, as the cumulative difference in measured rainfall and calculated evapotranspiration from April to September. In addition, KNMI calculates the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI). The SPI and SPEI provide more information on dry and wet conditions throughout the year, instead of only for summer half of the year. The KNMI also has a monitor that shows the spatial and temporal changes of the SPI. Other meteorological data, including potential net precipitation and SPEI, can be found on the KNMI climate dashboard.
Furthermore, Rijkswaterstaat and the water boards continuously monitor the current drought situation. Together, they developed the Droogtemonitor, an online information platform that provides year-round monitoring of water levels, enabling timely and informed action when needed.
Impacts from droughts
Droughts can have large impacts on water availability and water quality, and thus on a range of water dependent economic sectors and biodiversity. An overview of the impacts for the Netherlands is given in the policy summary De droogte van 2022 (PDF), and are described below.
Nature and biodiversity
Drought poses a significant threat to ecosystems that depend on surface water and/or groundwater. Lower water levels can lead to higher surface water temperatures, which negatively affect aquatic species, and increase the likelihood of harmful algal blooms. Increased evaporation leads to higher concentrations of nutrients in the water. Some plant and animal species are better adapted to withstand these changes, ultimately altering the dynamics of the local ecosystem. Reduced water availability may cause wetlands, streams, and ponds to dry up, disrupting habitats for rare and sensitive species. Amphibians may lose critical breeding grounds, and fish migration routes can be blocked. Prolonged drought can also weaken trees and reduce overall biodiversity. In lowland regions, drought may lead to salinisation and peat degradation, with lasting impacts on ecosystem health and resilience.
Wildfire risk
Drought significantly increases the risk of wildfires, particularly in dry, sandy, or forested areas. Prolonged dry periods reduce soil moisture and reduce vegetation moisture content, making it more flammable. Groundwater levels also drop, weakening the resilience of ecosystems. Human activity, such as recreation, can further increase ignition risks. Once a fire starts, dry and windy conditions can cause rapid spread, threatening nature reserves, infrastructure, and nearby communities. Wildfires also release large amounts of CO₂ and damage biodiversity. Effective wildfire management requires early warning systems, land-use planning, and coordinated emergency response strategies. For more information, visit the Wildfire page.
Agriculture
Agriculture is highly sensitive to drought, especially in regions with limited irrigation capacity and soils with low water-holding capacity. Crop yields will decline due to water shortages, particularly during critical growth stages. Farmers often respond by increasing irrigation, which raises costs and can strain groundwater resources thereby adversely impacting other water dependent sectors and/or biodiversity. While market prices may offset some losses, regional disparities remain. Long-term drought resilience depends on adaptive measures such as water-efficient practices and improved soil moisture retention.
Drinking water
Drought can impact drinking water supply by reducing surface water availability due to increasing salinity or contamination risks. Groundwater sources are generally more stable but may face overuse during prolonged dry periods. This can affect water availability for nature and agriculture. Higher temperatures often lead to increased water demand. To ensure supply security, water utilities may implement demand management, diversify sources, and invest in infrastructure such as storage basins and interlinked networks.
Industry
Industrial sectors rely heavily on water for processes such as cooling, cleaning, and manufacturing. In the Netherlands, actual water scarcity, the lack of freshwater resources to meet the standard water demand, is rarely the issue. Instead, drought-related impacts on industry are mainly linked to restrictions on cooling water discharge due to elevated surface water temperatures, and limited availability of high-quality intake water caused by salinisation. These constraints can disrupt operations and increase operational costs. Another significant impact is on inland waterway transport. Low river water levels during droughts can lead to delays or even halts in the transport of goods to and from industrial sites. This can affect supply chains and, in some cases, halt production. For instance, during the 2018 drought, Akzo Nobel in Twente experienced production challenges due to such transport disruptions. While many industrial processes are adaptable, ensuring long-term resilience requires investments in water efficiency, reuse technologies, and careful site selection that accounts for water quality and transport accessibility under drought conditions.
Flood defence
Drought can weaken flood defences by causing soil shrinkage, cracking, and vegetation die-off on dikes. Animal burrowing may also increase. Although many dikes recover after rainfall, repeated or prolonged droughts may compromise their integrity. Monitoring and maintenance are crucial, as is research into effective mitigation measures such as irrigation, grazing management, and structural reinforcement.
Subsidence and CO₂-emissions
In peatland areas, drought accelerates peat oxidation due to lower groundwater levels, leading to land subsidence and increased CO₂-emissions. These processes contribute to climate change and damage infrastructure. The extent of impact depends on drainage depth, land use, and soil composition. Monitoring and adaptive water management are key to mitigating these effects and preserving peat soils. For more information, visit the Subsidence page.
Built-up areas
Urban environments are vulnerable to drought through subsidence resulting in foundation and infrastructure damage, and stress on green infrastructure. Falling groundwater levels can damage buildings, roads, and trees. Older structures and areas with clay or peat soils are particularly at risk. Stress on green infrastructure can lead to increased heat stress and reduced recreation opportunities on the short term, whereas in the long term it could lead to additional cost of replanting or replacing green areas. As droughts become more frequent, cities must invest in monitoring, adaptive design, and integrated water management to reduce long-term damage and costs.
Infrastructure & shipping
Drought has a major impact on infrastructure and inland shipping routes. Lower river discharges and water levels reduce navigability, forcing vessels to carry less cargo and make more trips, which in turn increases transport costs, emissions, and delays. Lock operations may be limited to conserve water, further disrupting logistics. Prolonged low water levels can also weaken the structural integrity of canals, bridges, and quay walls.
In delta scenario Steam2050, the annual drought-related damage to inland navigation is estimated at €102 million, rising to €309 million in scenario Steam2100. In a T20 drought year, losses could reach €765 million. These figures reflect not only transport inefficiencies but also additional economic costs from storage needs, modal shifts, and increased emissions. Building resilient transport infrastructure therefore requires integrated water and logistics planning, including adaptive water level management and viable alternative transport options.
Economic impacts
Drought has significant economic consequences across multiple sectors in the Netherlands. This report published in May 2025 by Deltares (PDF) gives an indication of the economic impacts of drought. It quantifies the societal effects of drought for four key sectors: agriculture, shipping, CO₂-emissions from peat oxidation, and foundation damage. The analysis considers both average years and extreme drought years with a return period of once every 20 years (T20).
The impacts are assessed based on the future scenarios Steam2050 and Steam2100, from the 2024 Delta Scenarios. Further details can be found in the Delta Scenarios 2024 Brochure published by the Delta Programme (PDF), and on the Dutch climate scenarios page.
Agriculture
The agricultural sector suffers direct losses due to reduced crop yields and increased irrigation costs. In the Steam2050 scenario, the annual welfare loss due to drought is estimated at €126 million, rising to €315 million in Steam2100. In a T20 drought year, this could reach €779 million. Interestingly, higher temperatures and CO₂-concentrations, in combination with irrigation, can have a positive effect on crop growth, partially offsetting drought-related losses. Temperatures can also become too high for plant growth and then have negative effects. However, the reduction in agricultural land area results in a structural decline in welfare.
CO₂-emissions from peat oxidation
In peatland areas, drought lowers groundwater levels, accelerating peat oxidation and increasing CO₂-emissions. The total annual welfare loss from these emissions is estimated at €910 million in Steam2050, of which only €18 million is directly attributable to drought. The majority is due to rising temperatures and anticipated increases in CO₂- prices. In a T20 drought year, the damage could exceed €1 billion.
Foundation damage
Prolonged low groundwater levels can degrade timber pile foundations and cause subsidence in shallow foundations. Total repair costs for foundation damage are projected to rise from €23 billion in the reference scenario to €29.5 billion in Steam2050. Of this increase, approximately €906 million is directly linked to climate change. The greatest damage occurs in urban areas with older buildings, particularly in regions such as North Holland and Western Netherlands.
Total economic impact
The total annual economic damage from drought in Steam2050 is estimated at €246 million, excluding foundation damage. In an extreme drought year, this could exceed €1.7 billion. The largest structural loss stems from CO₂-emissions due to peat oxidation, followed by agriculture and shipping. Foundation damage represents a substantial long-term burden, especially in urban areas. These figures underscore the importance of resilient water management and targeted measures to mitigate the societal costs of drought. The total economic impact is expected to be larger, as the impact on many water users is not included, such as nature, recreation, industry, infrastructure damage due to low groundwater levels and damage due to salinisation in agriculture.
