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3.2        Water abstraction

3.2.1        Background

Hydrological regimes are key in maintaining healthy aquatic habitats and the quality of aquatic ecosystems, and their role in supporting the achievement of environmental objectives is fully recognised in the WFD. Agriculture can have widespread impacts on the hydrological regime of river basins and aquifers, by changing land use and altering natural hydrological flows across the landscape, and by increasing abstraction in surface water and groundwater bodies. In addition, irrigation infrastructure often involves the building of water storage (reservoirs) and water transfers.

This chapter focuses on agricultural abstraction pressures, which can play a significant role in exacerbating minimum flows needed for health stream ecology. Unsustainable levels of abstraction can reduce river flow to levels that are critical for water-borne flora and fauna. Reduced flows result in a host of other impacts, from lower dilution of pollutants, to the disruption of sediment and nutrient transport, and alterations to natural habitats conditions, including wetland and transitional waters (Chapter 3.6).

Abstraction in groundwater poses several threats too. Groundwater is a crucial source of water for nature, especially wetlands and coastal ecosystems, and for water supply, especially for drinking water. Abstraction in groundwater can deplete aquifers and increasing the risk of pollution and saline intrusion. Abstraction in groundwater bodies may not have an immediate impact on surface water bodies, but it may reduce river base flows in the medium term by reducing return flows into surface water bodies.

3.2.2        Current level of agricultural water abstraction

In the 2^nd RBMP under the WFD , water abstraction for agriculture is reported as a significant pressure on the water environment in 64% of EU-28 countries (18 out of 28) and 44% of RBDs (85 out of 194). The countries with the highest proportion of surface water bodies significantly impacted by agricultural abstraction are Cyprus, Spain, France, the Netherlands, Bulgaria, Greece, Hungary and Italy. For groundwater bodies, Cyprus, Hungary, Greece, Spain, Malta, Italy and France are the most affected countries.

Agriculture abstracted on average 50 km³ of water between 2008-2017 in the EU-28, which is about 24% of total water abstraction (EEA, 2020a). In the EEA-32, total agricultural abstraction was on average 92 km³ during that period, with Turkey abstracting on average 40 km³ of water every year. Most of the water abstracted by agriculture is consumed by the plant or lost as evapotranspiration, and therefore does not return to the environment (Box 3.4). As a result, agriculture is the largest net water user in Europe, accounting for 59% of net water use in the EU-28 (EEA, 2020a).

Box 3.3  Accounting for water used in irrigation.   

Water abstraction refers to the withdrawal of water from a water source e.g. pumping water from groundwater, harvesting water from a spring, extracting water from a river, lake or reservoir. In contrast, water use refers to net water consumption, which is not returned to the environment in the form of return flows or losses due to evapotranspiration.

In agriculture, unintended losses can occur at all parts of the distribution system. For instance, leakage may occur in the canals and pipes bringing water from the abstraction point to the field. In the field, the efficiency of the irrigation methods and technologies or the meteorological conditions at the time of application will influence losses due to infiltration and seepage to groundwater, and evapotranspiration rates. Irrigation management aims to reduce these losses.

In addition, different crops will have different water consumption intensities. For example, cotton crops water need vary between 7000 and 13000 m³/ha while beans water needs are around 3000-5000 m³/ha. Water consumed by the crop will not return to the local environment.

In agriculture, a large share of abstracted water is not returned to the environment as it is consumed by the plant or evaporates into the atmosphere. This contrasts significantly with other large water uses in Europe, such as public water supplies, which return most of the abstracted water as wastewater discharges.

Sources: ESTAT, 2020i; Brouwer and Heibloem, 1986

It is estimated that about 50% of water abstracted for agriculture in the EU-28 between 2008 and 2017 is from groundwater bodies (EEA, 2020a). The other half is divided between reservoirs (27%) and rivers (23%). The share of abstraction between surface water and groundwater differs between countries. Groundwater abstraction for irrigation exceeds 50% of total water abstraction for irrigation in Malta, Lithuania, Denmark, Cyprus, the Netherlands, Germany and Portugal. Some of these countries, such as Cyprus and Malta, have more than 50% of their groundwater body area in bad status.

Italy, Spain, Greece and Portugal accounted for 91% of water abstracted for agriculture in the EU-28 between 2008 and 2017 (EEA, 2020a). This is also reflected in an analysis of the spatial distribution of the most intensely irrigated areas (Map 3.3). In those countries irrigation water abstraction levels ranged between 4500-9500 m³/ha in 2015. Other Mediterranean countries, such as Cyprus and Malta, present similar high intensities. Bulgaria has the highest irrigation water abstraction intensity (9000 m³/ha), while high rates are also found in France, Denmark, Lithuania and Romania (2000-3000 m3/ha).

3.2.3        Trends in water abstraction

Long term statistics on agricultural water use are difficult to recreate given the lack of adequate reporting on irrigation water use before the 1990s. Most studies indicate that water abstraction for agriculture has steadily grown in the second half of the 20^th century with the expansion of irrigated agriculture (Molden et al., 2007a).

Since 1990, total abstraction from agriculture has reduced in the EU-28, from 80 km³ in 1990 to 53 km³ in 2017 (EEA, 2020a). The largest change in the EU-28 occurred in 1990 with the change of political system in Eastern Europe, where agricultural water abstraction has decreased from from 8 km³ in 1990 to 1 billion km³ in 2017 in Romania and Bulgaria alone. 

In total, a fall can also be observed in 16 countries of the EU-28 (EEA, 2020a). Reasons for this evolution are complex and locally specific. In some countries, such as France, it can be associated with the shifts in prices, e.g. favouring less water demanding cereals at the expense of more water demanding maize, as well as stricter abstraction controls imposed by WFD to protect ecosystems during droughts, changes in agricultural policy priorities, or loss of agricultural land to urban area (Martin, 2013).

Some countries have increased agricultural water abstraction such as Belgium, Lithuania and Cyprus. In the EEA-32 countries, Turkey has seen a significant rise in its agricultural abstraction, from 27 billion km³ in 1990 to nearly 46 km³ in (EEA, 2020a).

3.2.4        Unsustainable water abstraction and areas under water stress

The degree of impact of agricultural abstraction on the aquatic ecosystems depends on the volume of water abstracted, the type of resource exploited, the location of the abstraction point, and the timing of the abstraction, in particular with regards to surface water and groundwater levels and climate conditions. The multiplication of agricultural abstraction points can cumulatively lead to a significant impact on the overall water balance of a catchment or an aquifer, and contribute to water scarcity. It can be particularly impactful on the water environment because abstraction occurs during the dry season when crop water demand is at its highest, while river flows are at their lowest.

Water scarcity is a measure of water availability in relation to human demands. It occurs when the demand for water by different economic sectors exceeds water availability. It is not only related to water demands by agriculture, but to the demand of all sectors that rely on water: households, industry, cooling water and agriculture. These activities are unevenly distributed across Europe, and some have more constant demands whereas especially agriculture has very strong seasonal demands.

Water stress can be used to assess the degree of water scarcity, and is calculated as the imbalance between renewable water resources and water demand. It is expressed by the water exploitation index (WEI+) as the percentage of total water use from surface and groundwater systems over the renewable freshwater resources for a specific area and time. A WEI+ above 20 % implies that a water resource is under stress, and more than 40 % indicates severe stress and clearly unsustainable use of the resource. 

The seasonal variation of WEI+ has been calculated for Europe (Figure 1.4).  Water scarcity associated with agricultural activities have a strong seasonal variation especially evident in southern European countries such as Spain, Italy and Greece. Agricultural water use also contributes to water stress in other regions, where irrigation is developed.

Supporting sustainable abstraction in agriculture and restoring hydrological regimes in rivers and groundwater levels are essential to supporting healthy ecology, enhancing natural resilience to drought, and ensuring that rivers continue to support wellbeing and recreation.