Who Gets the Water?

Spain is usually described as a country that is drying out. The pictures are familiar: cracked reservoir beds, village church towers rising out of empty lakes, water lorries in Catalonia, a lagoon in Doñana that has turned into a dusty plain. Climate change is real, and the south and east of the peninsula will very likely become drier still. But the pictures hide a second story. Spain's water crisis is also a crisis of distribution: of who is allowed to take water, where it is taken from, and who carries the cost when there is not enough.

This essay asks a simple question: who gets the water? The argument: in Spain, scarcity is produced as much by decisions as by the weather. A model built on irrigated export agriculture has turned the driest basins into the most intensively used ones. Aquifers are being drawn down faster than they refill, wetlands and lagoons pay the bill, and the institutions that allocate water give the largest users a strong voice. None of this is a secret. What is missing is a political answer to the question of who should give way.

Chapter 1

A dry country, or a thirsty one?

Spain's rainfall is famously uneven. Galicia and the Cantabrian coast are green and wet; the south-east around Murcia and Almería is semi-arid. To bridge that gap, the twentieth century built one of the largest dam networks in the world. Today the reservoirs on the mainland can hold about 56,000 hm³; in February 2026 they were 83 per cent full (MITECO, 2026b). Yet even in wet years, some basins remain in permanent deficit.

The European Commission measures this with the Water Exploitation Index plus (WEI+), the share of renewable freshwater that is actually consumed. Above 20 per cent a region counts as water-scarce; above 40 per cent the scarcity is severe. Spain as a whole averaged just under 20 per cent in 2017–2021. But in the Guadalquivir basin the index stood at 48 per cent, in the Guadiana at 50, in the Júcar at 72 and in the Segura at 100 per cent: on average, everything that flows is used (European Commission, 2025).

Climate change will tighten this squeeze. For the Mediterranean, the IPCC expects less rainfall (medium confidence) and, with high confidence, a decline in annual runoff of between 5 and 70 per cent depending on the region and the warming scenario (Ali et al., 2022). For Spain, the public research centre CEDEX projects that average runoff could fall by 11 to 14 per cent by mid-century compared with 1961–2000, and by up to 24 per cent by 2100 under a high-emissions scenario, with the Segura and Júcar among the hardest hit at around 37 per cent (Barranco et al., 2018). The basins that are already over-used are the ones that will lose the most.

Chapter 2

The thirsty field

So who uses the water? The clearest answer comes from the national statistics office. In 2018, the latest year for which the agricultural water survey has been published, 15,495 hm³ of water were distributed to Spanish farms for irrigation (INE, 2020). In 2024, all the public networks that supply homes, businesses and city services together received 4,267 hm³ (INE, 2026). The years differ, but the order of magnitude is clear: irrigation takes roughly three and a half times as much water as all of Spain's towns and cities.

Irrigated land is the engine of Spanish agriculture. According to the agriculture ministry's crop survey, 3.71 million hectares were irrigated in 2023, about 23 per cent of cultivated land (MAPA, 2024). That land generates around two-thirds of the value of Spain's crop production (MAPA, 2022). Much of it is exported. In 2025, Spain exported fresh fruit and vegetables worth 18.7 billion euros; by volume, 84 per cent went to other EU countries, according to the growers' association FEPEX (as reported by Forbes España, 2026). A lettuce in a Munich supermarket or a punnet of strawberries in Amsterdam carries water from aquifers in Murcia or Huelva with it.

Researchers call this virtual water: the water embedded in traded goods. Through its grain trade, Spain is in fact a net importer of virtual water, with imports rising in dry years (Novo et al., 2009). The problem is not the national balance but the geography: the water that leaves in fruit and vegetables is taken from precisely the basins that are already overdrawn. Garrido et al. (2010) therefore argue that the useful question is not how much water a country trades, but how much economic value and how many jobs each cubic metre generates, and at what ecological cost.

Chapter 3

The efficiency paradox

For two decades, Spain's official answer to scarcity has been technology. Between 2002 and 2015, modernisation programmes planned for more than 2.3 million hectares, with a budget of around 7.6 billion euros, upgraded 1.79 million hectares, mostly by replacing open channels and flooding with pressurised pipes and drip lines; public subsidies covered about 60 per cent of the capital costs (Berbel et al., 2019). Today, 58 per cent of Spain's irrigated land uses localised, mostly drip, irrigation and 81 per cent uses one of the systems the ministry classifies as efficient (MAPA, 2024). For 2021–2027, more than 2.1 billion euros of public and private investment is planned for further modernisation, about 700 million of it through the EU recovery plan (MAPA, 2022).

At the level of the field, this works: studies reviewed by Berbel et al. (2019) found that modernised schemes apply on average about a third less water. At the level of the river basin, the picture is different. Water that used to flow back from leaky channels into rivers and aquifers was already being reused downstream. When farmers save water at the field, they often use it to irrigate more land or to switch to thirstier, more profitable crops. The water that actually evaporates from the basin can stay the same or even rise. Grafton et al. (2018) call this the paradox of irrigation efficiency, and economists speak of a rebound effect (Berbel et al., 2015).

A review of the international evidence concludes that efficient irrigation technology "should not be viewed as a tool for achieving water conservation"; if conservation is the goal, policies that reallocate water between uses, for example from irrigation to the environment, are needed (Pérez-Blanco et al., 2020). Spanish researchers warned early that the gains were getting lost in translation between the farm and the basin (Lopez-Gunn et al., 2012). There is also an energy cost: pumping water through pressurised networks uses many times more electricity than gravity irrigation (Berbel et al., 2019). Modernisation made Spanish irrigation more productive. It did not, by itself, give any water back to rivers, wetlands or aquifers.

Chapter 4

Doñana: when a wetland pays

Nowhere is the cost of over-pumping more visible than in Doñana, the great wetland at the mouth of the Guadalquivir and a UNESCO World Heritage Site. The marshes and lagoons are fed by the Almonte-Marismas aquifer, which also supplies the strawberry and berry farms of Huelva and the beach resort of Matalascañas. Scientists have documented the consequences for decades. A recent synthesis by more than twenty researchers finds that groundwater levels in the deep aquifer have fallen by up to 20 metres, that the water table has dropped by half a metre to two metres in some areas, and that the flow of the Rocina stream has fallen by 62 per cent (Green et al., 2024). Landsat images of 316 ponds from 1985 to 2018 show that about 59 per cent of them have not flooded since at least 2013 (de Felipe et al., 2023).

In 2021 the Court of Justice of the European Union ruled that Spain had failed to protect Doñana: the river basin plan did not account for illegal abstraction or for the water drawn for the resort, and since 2006 Spain had failed to take appropriate measures to prevent significant disturbance of the protected habitats (CJEU, 2021). Two years later the decline became impossible to ignore. Santa Olalla, the largest lagoon and the last considered permanent, was completely dry in late August 2023, for the second year in a row, something that had never happened in two consecutive summers before (EBD-CSIC, 2024).

The politics followed the hydrology, but in the opposite direction. In April 2023 the governing Partido Popular and Vox began processing in the Andalusian parliament a bill that would have regularised irrigation on land around Doñana that had been farmed without water rights. After protests from scientists, the European Commission and the national government, the bill was suspended. In November 2023 the regional and national governments signed an agreement worth more than 1.4 billion euros. Its core is a buy-out: farmers in the northern crown of Doñana who stop cultivating and renaturalise or reforest their land receive 100,000 euros per hectare, paid over five years (Ayuntamiento de Almonte, 2023). The deal shows two things at once: that taking water back from agriculture is possible, and how expensive it becomes once a farming economy has been built on water that was never legally there.

Chapter 5

Water that travels

If one aquifer is empty, bring water from somewhere else. That idea runs through Spanish water policy like a river. The geographer Erik Swyngedouw (2015) has described how, from the late nineteenth century onwards, engineers and politicians promised to "correct" Spain's uneven nature with dams and canals, a project of hydraulic modernisation that was continued under the Franco dictatorship and gave irrigators a central place in the nation's self-image. Its most famous product is the Tagus–Segura transfer, which since 1979 has carried water nearly 300 kilometres from the reservoirs of the upper Tagus to the south-east.

By law, up to 600 hm³ a year can be sent to the Segura basin, 400 of them for irrigation and 110 for drinking water (MITECO, 2026a). In practice, far less arrives: on average about 336 hm³ a year, and the legal maximum was reached only once, in 2000/01 (Morote & Rico, 2018). In the drought year 2022/23, only about 116 hm³ were transferred for irrigation (MITECO, 2026a). Meanwhile, the Tagus itself suffered. Downstream of the dams, at Aranjuez, minimum flows were long criticised as too low for a living river. The revised basin plan approved in 2023 therefore raises the ecological flow at Aranjuez step by step, from about 6 to 8.65 cubic metres per second by 2027, which reduces what can be sent south in dry years (Real Decreto 35/2023).

The transfer has thus become a zero-sum conflict between regions. Castilla-La Mancha, where the water comes from, sees it as an export of its future; Murcia and Alicante, where it is used, see any cut as a threat to their farms and jobs. The Segura basin authority puts total demand at 1,805 hm³ a year, 1,526 of them agricultural, against resources that include 340 hm³ of desalinated water and 312 hm³ brought in from other basins (CHS, 2022). Whichever figure one uses for the gap, it is filled in part by over-pumping, which is why the Segura stands out on the map.

The Mar Menor shows the end of that chain. The coastal lagoon south of Murcia receives nitrate-rich water from the intensively irrigated Campo de Cartagena, both on the surface and through the aquifer. After decades of rising nutrient loads, the lagoon flipped in 2016 into a turbid state, known locally as the sopa verde or green soup, in which the seagrass meadows below about two metres depth died (Pérez-Ruzafa et al., 2019); in 2019 and 2021 oxygen collapses killed tonnes of fish (MITECO, n.d.). Measured nitrate inflows reach up to around a tonne of nitrogen a day on the surface and up to almost four tonnes underground (Álvarez-Rogel et al., 2020). In 2022, after a popular legislative initiative, the Spanish parliament made the Mar Menor the first ecosystem in Europe with legal personhood (Ley 19/2022), a status the Constitutional Court upheld in 2024.

Chapter 6

Who decides

Water in Spain is public property, managed by river basin authorities, the confederaciones hidrográficas. Spain invented the model in 1926 and it is often praised for organising water by catchment rather than by administrative borders. But who sits at the table matters. Under the Water Law, water users must hold at least one third of the seats on the governing board of each basin authority and at least one third on its water council, and they make up the majority of the operating boards that coordinate how the water of each system is used (Real Decreto Legislativo 1/2001). In most basins, the largest users are the irrigators' associations, the comunidades de regantes. Environmental groups, scientists and citizens are represented, but as minorities.

The same imbalance shows up in prices. The Water Framework Directive requires member states to recover the cost of water services, including environmental costs (Directive 2000/60/EC, Article 9). According to the Commission, Spain recovers about 70 per cent overall: 73 per cent from households, 80 per cent from industry and 67 per cent from agriculture, with tariffs giving weak incentives to save (European Commission, 2025). The average unit cost of urban water, including sewerage and treatment, was 2.02 euros per cubic metre in 2024, and households used 128 litres per person per day (INE, 2026). Markets for water rights exist, but they are small: in 2007 trades amounted to less than one per cent of national use, although they reached around 4 to 5 per cent in the Júcar and Segura (Palomo-Hierro et al., 2015), and there are no official figures on many informal deals (De Stefano & Hernández-Mora, 2016).

When drought hits, the hierarchy becomes visible. In early 2024, with the Ter–Llobregat reservoirs at about 16 per cent, Catalonia declared a drought emergency for some six million people in the Barcelona area, with a cap of 200 litres per person per day on municipal use and cuts of up to 80 per cent for irrigation (El Independiente, 2024). Coastal cities increasingly turn to desalination; Spain operates around 765 plants producing some 5 million cubic metres a day (Europa Press, 2024). Desalinated water is reliable but costly and energy-intensive, at around 3 to 4 kWh per cubic metre (Europa Press, 2024; MITECO, 2022). Who pays for this new water, farmers, tourists, households or the taxpayer, is one of the most important and least discussed questions of Spanish water policy. Tourism adds to local peaks, too, even though its share of total use is small (Gössling et al., 2012; Hof & Blázquez-Salom, 2015).