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Freshwater (Spain)

Why should we care about this issue

Published: 26 Nov 2010 Modified: 08 Apr 2011

Spain is a Mediterranean country with dry or very dry summers that can be exacerbated by long droughts. In the last 20 years, natural water resources have undergone great fluctuation, but have generally fallen by an average 5 % in the whole country with the exception of the Atlantic coastal areas, which are rainier.

This climatic characteristic of such irregular precipitation has led to the implementation of a major regulatory infrastructure capable of guaranteeing supply, and policies have been developed focused on reducing water usage and the sustainable use of this resource. Throughout its history, and in particular from the beginning of the 20th century, Spain has developed a hydraulic works policy resulting in a large number of dams (more than 1200) with an approximate capacity of 56 000 hm3, over 100 of which had already been built before 1915.

Spain has been a pioneer dealing with hydrological and hydraulic problems using a territorial focus based on drainage basins managed through policies in the second half of the 19th century and the first third of the 20th, in order to take advantage in a rational way of the scarce and irregular water resources available. Recently, Royal Decree 125/2007 of 2 February 2007 has established the scope of river basin districts and has introduced this new administrative figure to adapt our legislation to the Water Framework Directive.


River Basin



The state and impacts

Published: 26 Nov 2010 Modified: 08 Apr 2011

General features: the hydrographical network and precipitation regime

Spain is one of the most mountainous countries in Europe. The mountains map out the presence of three slopes (Cantabrian, Atlantic and Mediterranean) and define the extension of the eight major basins of its principal rivers.



Rivers in Spain


With the exception of the northern and northeastern parts of the country,  the climate has scarce precipitation and intense evapotranspiration, which are characteristic of the Mediterranean climate, leading to a small amount of water that runs across the surface. In general, the rivers on the peninsula have a small absolute flow except for two – the Duero and the Ebro - which have a significant flow.

The amount of rain that falls on a certain territory is of particular importance. The average annual precipitation in Spain from 1941 to 2008 was 663.3 mm, with a maximum of 969.3 mm in 1960 and a minimum of 469.0 mm in 2005.

Water reserves

Spain has a large number of big dams in order to create water reserves for water consumption and energy generation. Of the total capacity of reservoirs containing more than 5 hm3, (55,111 hm3 at the beginning of January 2010), 17 391 hm3 (32 %) were reservoirs used for hydroelectric generation and 37,720 hm3 (68 %) for water consumption, mainly for irrigation and drinking water supply.

The ‘’Peninsular hydraulic reserve’‘ graphs published periodically by MARM in the Hydrological Bulletins (also published in the MARM Status reports) show the situation of these reserves in the last two years and compare them with the average situation in the last five and ten years.

Water use

According to data facilitated by the National Institute of Statistics (INE)  (Survey on water supply and treatment), during 2008, 4 941 hm3 of water was fed into the urban supply public networks in Spain. Of this amount, 75 % (3 732 hm3) was registered as water distributed for use in homes, in the different economic sectors (industry, services and livestock farming) and for municipal use, which represents a 1.2 % reduction from the year 2007. It excludes water used in irrigated agriculture which was 15,313 hm3 in 2008. In the same year, mean water consumption in households was 154 litres per inhabitant and day, 1.9% less than the 157 litres/inhab/day registered in 2007.

There is a dissociation between the upward trend of the GDP in recent years (current prices), and the use of water distributed for public supply. The more efficient use of water can be clearly observed from 2004 until 2007.



General Quality Index

For recent data on water quality, the ‘’General quality index for water’‘ (ICG), taken from ‘’The Environment and Rural and Marine Affairs 2008’‘ can be used. It measures the quality of surface freshwaters without taking into consideration their potential for different uses. The indicator is obtained by combining 23 parameters and by weighing the value of each quality parameter in the indicator total using linear equations. According to this indicator, surface water quality has improved during the period from 1998 to 2008, as measured at control stations throughout all water basins.

The percentage of stations with an ICG value classified as unacceptable has undergone significant reduction from 11 % in 1998 to 0.20 % in 2008. In fact, there has been a rise in recent years in the percentages registered by stations in the categories of ‘intermediate’, ‘good’ and ‘excellent’.


ICGICG caption


For more information, data for nitrate pollution, salinisation of groundwater bodies, organic pollution of rivers (BOD5 and ammonia), processing of waste water and quality of bathing water are available on The Environmental Profile of Spain. An indicator-based report, 2009 and The Environment and Rural and Marine Affairs in Spain - 2009.

One of the negative impacts of precipitation regimes is excess rainfall in very short periods of time, which can lead to flooding, with serious economic consequences and truly dramatic social circumstances and even deaths. Of the 897 fatalities from natural disasters in Spain in the period 1995 to 2008, flooding was responsible for the largest number of victims (29.3 %). 297 persons died from flooding in Spain in the period 1990-2008.


An example of impact in a water environment: breakage of the dam in the Aznalcóllar pond

On 25 April 1998 the dam wall broke in a tailings pond for a pyrite mine in Aznalcóllar (Seville). As a result there was major spillage of acid water and very toxic sludge containing high levels of heavy metals. The spillage amounted to some 4.5 hm3 (3.6 of water and 0.9 of sludge), flooding over the riverbanks of the Rivers Agrio and Guadiamar along some 40 km in the case of the sludge and 10 km more for the waters, with an average width of about 400 m. The toxic spillage from Aznalcóllar destroyed crops, fauna, flora and soil, causing significant economic damages and severely affecting river life (initially, 30 tonnes of dead fish and crabs were removed, asphyxiated by the large number of suspended particles in the water and as a result of extreme acidity).

After several years of restoration work, the polluted zone is relatively clean. A Green Corridor has been created to provide natural protection of the damaged zone and surrounding expropriated land, in order to unite Sierra Morena and Doñana. Fishing, hunting, grazing and harvesting are prohibited in this corridor; reforestation and conservation activities continue, several bird hides have been built as well as different zones for leisure and recreation. In November 2004 the company Boliden-Apirsa was sentenced to pay some EUR45 million in compensation for the damages caused, which is a considerably lower sum than the economic losses suffered and the investments made by the Public Administrations.




The key drivers and pressures

Published: 26 Nov 2010 Modified: 23 Nov 2010

Most of the hydrographical network is affected by pressures derived from human activities. About one-third of water bodies reflect some type of impact, and in 24.74 % this impact is probable and in 9.15 % it has been demonstrated. In a considerable number of cases there are no data available (37.68 %) and in 28.43 % of water bodies no type of impact has been registered. The data used in the above analysis are prior to 2005 and were published by the Directorate General for Water, of the Ministry of the Environment and Rural and Marine Affairs in ‘Hydrological Planning: a summary of general studies on River Basin Districts in Spain’, [s.a.: 2007]. Below is a list of the key drivers/pressures that act on water resources.

The Spanish economy has undergone strong growth in the last decade. Spain's entry into the EU made it necessary to adapt the productive system, leading to a strong development of the services sector and industry. The services sector is principally made up of tourism services, in which the hotel and catering sector is particularly noteworthy.

Amongst the pressures that economic development in Spain has had on water resources, the following are of note: population growth, increased irrigation in agriculture, the use of water in industry and — as a consequence of these uses — wastewater discharge.

  • The functioning of the economy, its expansion and individual and collective well-being of the persons, who make up the economy, need to have a major set of demands for water services met. Amongst these demands, drinking water services for human use under safe health conditions must be considered first and foremost as the essential demand. The tendency appears to indicate that there is an increasingly responsible use of water and a reduction of loss from public networks.
  • Spain is the second country in the EU in terms of Utilised Agricultural Area (UAA) (24.9 million hectares in 2007) and the third country in terms of number of holdings (939.5). Irrigation is used in 13.2 % of the UAA. The use of water on agriculture stood at 15,316 hm3 in 2008, representing a 5.5 % lower than 2007. The distribution of water used in farming (2008), according to the irrigation system used, was as follows: gravity and others (41.9 %), drip irrigation (33.6 %) and sprinklers (24.5 %), showing an evolution towards more sustainable methods in comparison with the previous years.
  •  59.2 million foreign tourists chose Spain as their holiday destination in 2007. This is a record figure that was the culmination of almost constant growth for the last 40 years, although it fell to 57.3 million tourists in 2008 and 52.2 million in 2009, as a consequence of the deceleration of the world economy.
  • According to the National Institute of Statistics, in 2008 22.3 % of water supplied to the urban supply networks was destined to the economic sectors, including industry. This figure was 2.3 % lower than the previous year.


The 2020 outlook

Published: 26 Nov 2010 Modified: 23 Nov 2010

Urban use is influenced by a significant population increase, which has been particularly notable since the turn of the century. However, there have been encouraging signs in the most recent data on urban supply, especially with regard to water use in homes. Water losses in public networks are also being reduced, for example from 16.7 % of all water supplied in 2006, to 15.9 % in 2007.

With regard to reservoirs, Spain has a large number of dams, which, except in extreme drought situations, have guaranteed water reserves of about 50 % of total capacity in recent years.

In relation with water quality, the ‘National Plan for Water Quality: Water Treatment and Processing 2007-2015’ has laid the grounds for compliance with the obligations derived from the WFD. This Plan is being implemented through agreements with Regional Governments, and particular importance is being given to sensitive areas.

There are 2,381 agglomerations with more than 2,000 population equivalent, in Spain. At 31 December 2008, the distribution according to the load in equivalent inhabitants was: 77 % conformant, 14 % under construction and 9 % non-conformant. These figures give an idea of the major management effort that water treatment and processing implies for public administrations overall.

Existing and planned responses

Published: 26 Nov 2010 Modified: 23 Nov 2010

The Water Framework Directive 2000/60/EC enforces Member States to draw up timely reports on the pressures that have an impact on water bodies with the aim of achieving the proposed quality objectives by 2015.

In 2007 National Plan for Water Quality 2007-2015 was approved, and this plan is contributing to the achievement of the objectives for the quality ecological status that the Water Framework Directive requires by 2015.

Thus, a series of plans and specific programmes are being implemented to deal with the main challenges in water supply in a sustainable way. The following are of particular note:




The country assessments are the sole responsibility of the EEA member and cooperating countries supported by the EEA through guidance, translation and editing.

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