Tajo Hydrographic Confederation

Confederación Hidrográfica del Tajo
Avenida de Portugal, 81
Tfno. 34 91-535.05.00
Fax. 34 91- 554 93 00


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The Tagus basin is the third largest in the Iberian Peninsula, occupying an area of ​​about 88,700 km2, of which about 55,800 km2 are located in Spain (69%) and about 24,900 km2 (31%) in Portugal. The Tagus is the longest river of the peninsula, with 827 km in Spain, 230 km in Portugal and 43 km border between the two countries, giving a total of 1,100 km

The Tagus basin is that they depend on a greater number of inhabitants for urban water supply, close to 11 million people of which 6 million are in the Spanish part of the basin (5 million just in the province of Madrid), more than 3 million are in Portugal and close to 2 million are supplied from the river in southeast Spain (Alicante and Murcia) and the Guadiana basin.

Note that the two national capitals of the peninsula depend on the basin as well as the main transfer in Europe. It also supplies water in the Spanish zone of the basin of 120,000 ha. public irrigation and 110,000 ha. private irrigation. In Spain, the basin includes territories of the Autonomous Communities of Castilla-La Mancha, Extremadura, Madrid, Castilla-Leon and Aragon.


A Hydrological Plan is a document that establishes a water use management in the area of ​​a basin for a specified period.

  • Define the guidelines for applications and uses of the water.
  • Sets broad guidelines and priorities for a comprehensive and balanced management of the resource.
  • Sets the sort of uses that is derived from the different sectoral planning (agriculture, livestock, urban supply, industrial, etc.). To which the Plan takes into account and provides service in search of a global module balance competing interests, introduce rationality in resource management and, ultimately, preserve natural systems.

The time horizon of the Plan is twofold: 10-20 years, with periodic reviews provided for terms not exceeding eight years, according to Rule 110 of the Public Water Supply.

A consensus approval

It has developed a technical front, global analysis and resource exploration in the basin, relative to other basins and to respect the experiences of other countries.

It also has unfolded in an administrative field of public information and participation. The process has required great efforts of dialogue and consultation between all parties involved mainly central government, representatives of the Autonomous Communities that are part of the basin and users (municipalities, irrigators, hydroelectric groups, environmental associations, etc).

The proposed Water Plan Tajo Basin obtained under the Water Board of the basin, a collegial body of the Confederation on 18 April 1997 with 60 votes for, 1 against and 2 absent. This proposal was forwarded to the Ministry of Environment, after which the report was submitted to the National Water Council, which also obtained their agreement in April 1998 and approved by Royal Decree 1664/1998 of 24 July 1998.

Plan Objetives

According to Article 38 of Law 29/1985 of 2 August Water are set as objectives of the Basin Hydrological Plan of the Tagus:


  1. Meeting the demands in quantity and quality, present and future, through the rational use of water resources, surface and groundwater, and the technical, human and economic.
  2. The balance and harmonize regional and sectorial development of the basin.
  3. The implementation of efficient management that takes advantage of technical innovations to achieve the increased availability of the resource through the rationalization of employment through the coordinated use of surface and groundwater resources and the realization of the related works for use .
  4. Resource protection in harmony with environmental needs and other natural resources.
  5. The guarantee of quality for each use and conservation of the environment. Specifically, that water intended for human use and consumption meet the sanitary conditions.
  6. The protection of population and territory of the hydrological extremes such as floods, droughts and floods.
  7. The protection, conservation and restoration of public water and management of recreational and cultural use of it.
  8. The conservation of water infrastructure and historical heritage of the watershed as hydraulic means to achieve the above objectives. There are other specific objectives that emanate from the implementation of commitments undertaken at the sector specific legislation in relation to the river Tagus, and in particular: The laws governing the pooling Tajo-Segura, the 21/71, 52/80 and the Royal Decree-Law 8/1.995 as well as those that have served the public interest to state regulation works, performances and changes in irrigation.

Integrated water management: surface and groundwater

The Water Law is consistent with the principle of unity of the hydrological cycle. Accordingly establishing an identity of nature and function between surface water and subterrráneas, which, together, must be subordinate to public interest and in the service of the nation.


Hydrological Plan Tajo Basin has been drafted taking into account the different characteristics of both respecting the relationship and interdependence between surface water and groundwater.

The Plan has taken the complementary hydrological and surface waters where it has become necessary and generally postulated coordinated management of those for which it has a number of measures, defines a perimeter of protection of the aquifer in the area of Madrid and enhances the knowledge of surface and ground water resources through control networks and studios to step hydrogeological research, rational use and protection against pollution and overexploitation of groundwater.

The protection of the aquatic environment and the environmental dimension

The plan, according to the Water Act aims, among other objectives, rationalize water use in harmony with the environment and other natural resources.

This incorporates a broad set of environmental standards.

The quality of the water: The control and the fight against water pollution is a major challenge for those responsible for environmental, health and water policy in the Tagus basin.

In this respect the Plan seeks to improve water quality in the basin, which is especially important downstream of the large crowd in Madrid. Achieving the stated goal of quality in the River Tagus at Toledo step has become one of the most representative indicators of this Plan.

Have set the quality requirements in terms of water courses, rivers and fields, determining the quality objectives for rivers, aquifers, bodies of water free, potable water intakes, etc.. considering the reference conditions to ensure that compliance will provide a suitable environment unfavorable hydrological conditions even.

He points out the guidelines and criteria for treatment and discharge proceedings, defines the planned reuse of effluent and the conditions according to their quality control practices and procedures and adopt rules of existing discharges, also indicates performances emergency and fly-tipping. Proposes new control stations, integrated into networks and SAICA COCA, and poses a quality control plan of water.

The demand environment: Hydrological Plan Tajo Basin planned resource allocations to ensure the needs of the environment associated with water quantity and quality.

Hydrological Plan Tajo Basin water considered necessary for the maintenance of river ecosystems is equivalent to a demand, and as environmental demands set the volumes needed in the allocation of resources. As a general rule has been considered that the required volume evaluated monthly contributions should not be less than 50% of the average contributions of the summer months. It sets as its goal the study  of each section of river from the hydraulic point of view, biological, etc. to clarify the environmental demand in each season, especially downstream of reservoirs in areas of concern fish farming, salmonid rivers and rivers with acceptable biological indices.

However the approval of the Plan implies the implementation of such demand at least in normal conditions and has clarified the volumes to be available even in reservoirs supply to address a situation as normal.

Perimeter protection and the conservation and recovery of the resource and its environment determines the criteria and priorities plan to delineate protection zones in the wetlands and lakes, and major gaps in the bird population or its biological richness, showing listings reservoirs, wetlands and unique spaces that should be protected

In the Tagus basin there are 95 wetlands covering over 0.5 ha. where action is planned in 2 phases. The first, general description of  ecological and hydrological processes and evaluation of their water needs and, second, recovery in those who are affected and implementation of environmental management plans.

Assume protected natural areas declared by the Autonomous Communities and is committed to promoting restoration. It includes the need to conduct the environmental assessment of critical infrastructure are planned.

Soil conservation and management plans, forest Action on the subject matter within the Hydrological Plan of the River Tagus is articulated within the National Forest Restoration Plan in its scope and Law December 19, 1951 on reforestation and management of agricultural crops of the land in the watershed integrated feeder reservoir regulation.

It also assumes the Central Land Plan in regard to the fight against erosion. It takes what they have planned the competent authorities, focusing specifically on the conditions that these plans may pose to the water environment and infrastructure. Hydrological Plan focuses its attention in the field of reforestation, protection of catchment areas and margins of the reservoirs to prevent soil erosion and siltation of these, as well as on the banks of rivers, to protect fundamental to floods. It also pays special attention to afforestation in areas dominated by the infrastructure of the Tajo-Segura. The Plan includes a reservoir protection program and a program of conditioning and straightening of rivers. Are also developed in coordination with the Autonomous Communities, a program of restoration and recovery of vegetation cover and fire protection program.

Resources uses

The Plan has devoted significant attention to the study of the use of available resources and analyze the efficiency of current exploitation.

The Plan has reviewed the existing demands, objectified endowments, set the minimum efficiency levels and reveals the imbalances of balance demands / supplies showing the excessive demands and potential surplus.

It has also made some predictions for the future and set goals to achieve for the different uses of water depending on destination, including volumes and minimum ecological conditions.

The Plan has started from the principle that one way to make a rational use of water is achieved by efficient use by a stringent provisions and in line with this, it proposes on the one hand, a proactive and voluntary in order to dominate consumption of water in rivers and they perform better water management in all uses and demands and, secondly, is committed to conducting a priority review of concessions to conform with the determinations of the Plan.

Fixing the maximum amounts for these uses and establishes criteria for assurance of supply to reduce vulnerability and increase security against hydrological irregularity or incident of any kind.

The Plan clearly establishes maximum amounts of irrigation for different target irrigated areas of the basin, one by one, systems in accordance with its agricultural and modernization programs are also planned, all without prejudice to the rights established and operating freedom.

Special mention should be urban and industrial supply, representing about 30% of total demand, with the Madrid area that demands as much of the resource (80% of the total urban demand). We should also mention the important environmental demand (around 765 hm3/year) and cooling for the three nuclear power plants and a thermal (about 800 hm3/year).

Managing risk: Avenues, floods and droughts

Protection against floods

The plan pays more attention to flooding from runoff or overflow channels Avenue. The flood protection is based on 2 types of actions:

  • Structural measures, such as preparation and protection of safeguards channels in reservoirs, soil conservation and forest hydrological corrections, etc..
  • Management and administrative actions such as zoning margins and flood-prone areas, changing the area of police, establishing warning systems, coordinated action programs Civil Protection and other agencies involved, and so on.

Within the first horizon of the Plan will analyze the actual capacity of the river reaches, floodplains and artificial obstacles, the feasibility of abolishing them. In order to prediction, monitoring and flood control is in the final stages of construction and commissioning the Automatic Hydrological Information System (AHIS).

Fighting Drought

The plan faces hydrological drought situations by defining a set of standards for emergency situations, primarily in terms of resources available for each type of demand and demand.

It outlines the rules for setting alarm levels in the reservoirs according to the water reservoir, the level of groundwater, snow reserves, and so on. and there are a number of considerations regarding the order and preference of the demands to reduce.

In particular, the supply system which manages the Canal de Isabel II is the minimum normal operating supply, below which is considered to begin hydrological drought and in the case of irrigation adopted criteria for allocate water based on available resources in relation to the demands.

Resource allocation and reservation

The reservation of resources, according to Article 77 of RAPAPH is defined as the corresponding appropriations established in anticipation of meeting the demands corresponding to the specific hydraulic works whose conduct is within the jurisdiction of the Public Administration, the State or Autonomous Communities, or public purposes. Consequently, reserves are established for the horizon to 10 years including the volumes of existing concessions, including:

Tarancón supplies and area of influence, Aranjuez, the Algodor, Almoguera-Mondéjar, Madrid, La Sagra Alta, Baja de la Sagra, Toledo and area of influence, Torrijos, Talavera de la Reina, palms of the Commonwealth Sorbe, Caceres and surrounding areas.

Almoguera irrigated land, Barajas de Melo, Tajuña, La Sagra-Torrijos, Alcolea and other potentially irrigable areas, predominantly local irrigation, such as some header dependent Tajo in the basin or Tiétar Henares, distributed in the provinces of Avila, Caceres, Cuenca, Guadalajara and Toledo.

It also establishes reserves for environmental emergencies in the reservoir of El Pardo in order to ensure the water quality of the river Manzanares in the urban section of the state capital and the demand environment in the Tagus River in Toledo hm3/mes 25.90, city ​​emblematic of this plan because it was considered as an indicator of river quality.

Standards and exploitation


Hydrological Plan Tajo Basin takes into account sectoral planning and seeks to satisfy the various plaintiffs and water compatibility. This formalizes a wide range of rules intended to ensure better utilization of the resource in the major uses and uses. So develop basic standards for improvements and changes in irrigation on energy use and recharge and aquifer protection. At the same time defines the guidelines for grants and review. With regard to irrigation and agricultural uses, the Plan has attempted to meet all potential claims included in the National Irrigation Plan or promoted by the competent bodies of the CCAA, reserving enough water and providing the infrastructure and necessary actions at the same time has conditioned the granting of concessions necessary to comply with requirements of rational water use, economic-financial holdings and environmental impact.

This has identified the requirements for feasibility studies of new irrigation systems, set the selection criteria of change, specific information systems should incorporate irrigation and drainage networks and specifies the need for improvements or changes and The infrastructure to provide an environmental assessment, also specifies the areas likely to change in irrigation within the horizons of the Plan.

The Plan aims to throughout this regulation more efficient water use, the adequacy of provisions and supplies to the improved management of irrigation systems.

With regard to energy use, the plan promotes the implementation of hydropower infrastructure leveraging existing state by building contraembalses and establishes criteria for evaluating energy use and impose the constraints of running essentially directed to respect the rules natural and environmental protection. Emphasis is placed on coordinating efforts with the Energy Administration, in collaboration with users hydroelectric and the need for guidelines for new uses and existing plants comply with the minimum ecological flow.

The Plan considers the development of the White Paper Groundwater, which will be taken into account in relation to the Tagus basin, for incorporation into the Water Plan. It sets standards for the operation and the definition of overfished perimeter protection, an issue that extends to the supplies and catchments for areas of special ecological, scenic, cultural or economic. Determines that each concession adequately justified the water needs, the required annual flow and its modulation during the year, in addition to the economic viability of harvesting. Points to the terms and conditions necessary for granting concessions in hydropower plants, in irrigation and groundwater.


  • The ninth one provision of the current Law 52/80 mandates the administration to take appropriate measures so that, through appropriate regulation, water transfers that are, at any time, surplus in the Tagus basin, and instructs the Hydrological plan of the River Tagus, the determination of such surpluses. In fulfilling this mandate, and for the determination of such volumes of surplus water has been taken into account under the ninth additional provision of Law 52/1980 two, the basic criterion of providing maximum security to the supply flow technique with target users of the Tagus, assuring his attention, without restriction, temporary and guaranteed 100% volume, and the adoption of appropriate safety criteria.
  • With these principles, the rule of exploitation that formula is to meet the demands of the Tagus permanently, without limitation, to determine at any time the surplus of available water by subtracting the 240 hm3 Entrepeñas and Buendia stock at the time. Consequently, no transfers may be made in any case, when stocks in these reservoirs does not exceed 240 hm3, even in the hydrological conditions planned in the next step. Such excess water can be run, proving that in no case exceed the combined annual total for the Guadiana and Segura basins of 650 hm 3, and proposed schedule to the risk of the transferred water user.
  • As for the exceptional hydrological conditions provided for in Royal Decree 2530/1985 for lifting by the Central Commission for Exploitation of the Tajo-Segura to the Cabinet decisions of transfer is considered to be in such conditions when, being fully guaranteed the Tagus consumption without any restriction, can not be guaranteed the minimum amount required to supply relief and irrigation in the Segura basin and referral for supply to the basin of the Guadiana. Technically, this situation will be identified when, earlier this month, the stock dam on the whole sum of Entrepeñas and Buendia reservoirs (measured in cubic hectometres) are below the value indicated in the table below for that month.
  • Notwithstanding the foregoing, the Central Commission for Exploitation of the Tajo-Segura, pursuant to the authority conferred by Royal Decrees 2530/1985 and 1972/1988, establish rules of operation of the reservoirs in order to ensure that no hydrological reach exceptional circumstances mentioned above.
  • The volume of stocks listed in paragraphs 2 and 3 above must be revised upwards, as provided in Art. 110 of R.D. 927/1988, if we observe the emergence of circumstances so warrant. Explicitly, should be reviewed immediately when the changing demands of the Tagus and Guadiana so require, primarily in relation to supply works of the plain of La Mancha, Ciudad Real and Puertollano, subject in all cases considered for this purpose both the harvesting potential referred to in articles 3, 4 and 5 of Law 21/1971, such as those arising by virtue of the provisions of the additional provision of Law 52/1980 ninth, and resulting from the granting of concessions for charged to reserves for future exploitation, resource-dependent regulated in header are included in this Water Plan.
Volume limit on the macroembalse Entrepeñas-Buendía, below which the transfer decisions are the Council of Ministers

Basic Infrastructure Plan

As a result of the demands for all concepts, practices and current and future harvests, has to address the basin's hydraulic system, allocated and reserved in the Plan defines a series of basic infrastructure necessary to serve and serving objectives manifold. According to the different objectives of the plan are classified into the following chapters:

Basic infrastructure of the plan:

  • Chapter 1. Meeting the demands in quality and quantity, present and future.
  • Chapter 2. Drainage and water treatment.
  • Chapter 3. Flood protection and other infrastructure improvements and protect the resource and its environment.
  • Chapter 4. Correction hydrological-forestry and soil conservation.
  • Chapter 5. Improvement and modernization of irrigation.
  • Chapter 6. New changes in irrigation.
  • Chapter 7. Hydroelectric infrastructure in the state.

The actual development of the works will be conditioned, if appropriate, to the relevant sectoral planning and favorable environmental impact statement.

Nothing is held not to be sued by the industry itself and respecting the legitimate rights of the parties involved and society as a whole.

In addition to basic infrastructure, the Plan includes programs that involve a number of key actions set, taken to be the following:

     Monitoring Program of the variation of water resources, natural and available.
     Program tracking the evolution of competing needs.
     Irrigation improvement program and new transformations.
     Use development program hydroelectric trich.
     Monitoring program of water quality and the implementation of sanitation and treatment infrastructure.
     Agenda for Protection, conservation and recovery of the resource and environment affected.
     Correction Program hydrological-forestry and soil conservation.
     Groundwater Program.
     Programme extreme water events.
     Basic water infrastructure program.
     Other programs and studies.

The computerized management of water

The Automatic Hydrological Information System (AHIS) currently being implemented in the basin responds to the need to rationalize and streamline resource management, improving the processes operating on three fundamental objectives:

Objectives SAIH

Inform, automatically providing real time data on climatic, hydrologic and hydraulic infrastructure status of the basin and creating a bank of hydrological data to serve for future planning and exploitation.

Prevent short-term changes in levels and flows in rivers and reservoirs, encouraging automatically in case of flood risk.

The integrated management of the exploitation of reservoirs and pipelines and canals of the basin through the instant knowledge of the availability of water resources.

To meet these objectives has had a network of telemetry and remote control that transmits and processes all captured variables.

It complements all Network Automatic Alert Water Pollution Network (SAICA). This network, composed of automatic stations located strategically appropriate river points, provides continuous monitoring of the water.

The automatic stations have their own characteristics based on measurement and data transmission in real time in normally disadvantaged.

They performed continuous measurement of different parameters, provided the effect of analyzers, facilities, auxiliary equipment and systems for remote data acquisition and advanced technology.

Water Plan Management

The Water Act determines that management plans are public and binding, subject to periodic updating and revision justified.

Hydrological Plan is conceived in the Tagus basin as a dynamic and flexible, open to constant reformulation process and reasonable, according to studies, analysis and contributions arising from day to day, within an economic context, social cultural and undergone profound changes.

The Water Act determines that management plans are public and binding, subject to periodic updating and revision justified.

Hydrological Plan is conceived in the Tagus basin as a dynamic and flexible, open to constant reformulation process and reasonable, according to studies, analysis and contributions arising from day to day, within an economic context, social cultural and undergone profound changes.

The Water Board may agree to review when deviations are observed in the data, assumptions or results of the plan so warrant. The Ministry of Environment may order an action reviewer.

In any case, the Act provides that conducted a comprehensive review of the plan and periodically every eight years after its approval.

The ater Basin Council will be responsible for raising the Ministry reviews the plan, counting with technical support from the Office of Hydrologic body Bakery.

Corresponds to the Tagus River Basin Plan track, having to report on its development, with intervals not exceeding one year, the board of the Government, the Water Board and the Ministry of Environment.

Will be subject to special monitoring aspects of the Plan concerning the variation of available water resources, changes in consumption, the characteristics of water quality and remediation programs.

The Water Council is a collegial body of the Confederacy. It is chaired by the president of the body and includes representatives from the Central Administration of the State, the autonomous communities of users and technical services of the Agency.

The Plan encourages and stimulates the process of planning an active presence there of all the agents involved in the River Basin management system of participation in such horn Assembly Members, Private Boards, the Board of Works and desembalsando Commission.

The Confederation of subsidiarity expresses its vocation by invoking the private sector and other public officials to be involved in implementing projects and actions proposed in the Plan.

This, indeed, seeks to enhance sustainable development and spatial planning in the basin, but also among all citizens to promote greater awareness and environmental assessment, landscape and recreational resource and about their environment.

The great achievements of the Plan

It is anticipated that the Hydrological Plan of the river Tagus, when executed step by step, with the necessary consensus in society as expressed through the Water Board, provide:


Catering to all populations of the basin with water quality, with the necessary assurance to allow social and economic development.

Better management of water, increasing efficiencies and improving their use to the River Basin in operational and administrative side.

A decisive impulse to the productive activities, wealth creation and generation of stable employment in the whole area of ​​the basin, and supply control interventions tailored to the principles of the new water culture, with a strong emphasis on rebalancing territorial.

The preservation and restoration of aquatic ecosystems.

A significant strengthening of environmental aspects in all the statements and actions of the body (establishment of environmental flows in rivers, pollution of water, maintenance and protection of riparian areas, etc.)..

A political consensus regarding the problem created called water war between different regions to define the surplus water.

The minimization of conditions caused by the dams, with plans to land restitution.

A configuration more flexible and decentralized organization, committed to the principle of subsidiarity.

And that all government is seen as a document made from the Tagus to the Tagus, although feeding the most important work of regional solidarity.

With an eye toward the future

Water is a natural element essential to life. is one of the assets that make it unique to our planet. Its greatest treasure.

Life emerged from the water. Life goes on depending.

Substantial part of the living. Is essential for metabolism and fundamental component of human diet.

Water is necessary for most productive activities. For agricultural crops, livestock, industry and power generation. For personal health, sanitation and beautification of our cities.

Courses and water bodies, rivers and lakes, are creators of landscapes, ecosystems support a cause for human settlements, unifying territories.

It is a symbol of prosperity, manifestation of beauty and expression of quality of life.

Water is also a guarantee for freedom and the autonomy of individuals and peoples. Expression of history and traditions. Generating cultural identity. Key to our future.

Water is public domain.

A rich heritage of all we need to protect and defend. By efficient use and solidarity that respects the common good, which is in harmony with nature that makes possible a future of hope for men and women in the territories of the basin. The best legacy for future generations.