Spanish National Hydrological Plan


  • Report on the Ebro Delta
    prepared by Professors
    John Day and Edward Maltby
The Ebro Delta and the Spanish National Hydrological Plan

A Commentary


John W. Day, Jr.
Louisiana State University


Edward Maltby
Royal Holloway, University of London

Prepared for The Foundation for a New Water Culture

September, 2002


Terms of reference and mandate

The Foundation for a New Water Culture requested that Professors John W. Day and Edward Maltby prepare an independent commentary of the Spanish National Hydrological Plan (NHP), especially related to the impacts of the Ebro water transfer, together with new dams, and irrigation projects on the lower Ebro river and its delta. The issues to be addressed in the report include the significance of the Ebro delta, the environmental impacts of the NHP on the lower Ebro, its delta and coastal waters, the responsibility under relevant international obligations concerning biodiversity, water and wetlands, and the future scenarios which may result from different actions.


In this brief commentary we attempt to draw attention to key aspects of the debate concerning the NHP which deserve more detailed consideration, especially by the European and wider International community. We are concerned in particular that an opportunity is not lost on the part of the responsible authorities to demonstrate awareness of the need for a new approach to integrated and sustainable water management, recognising the obligations under European legislation and other relevant international obligations in order to meet the legitimate economic requirements of people whilst maintaining environmental quality and conserving biodiversity.

Considerable debate has surrounded the possible impacts of the proposals within the NHP on the lower Ebro and particularly its delta. In this commentary we examine:

(1) The significance of the Ebro delta and the functional relationships with the hydrological regime of the basin.
(2) The likely impacts of the NHP on the delta with particular reference to the issues of biodiversity, sustainable use of natural resources, global climate change and subsidence in the delta, environmental quality and protection together with human welfare.
(3) Examples of relevant European legislation, obligations and recommendations under international conventions and other relevant experience and recommendations, to assist in better decision making and management of the Ebro basin and delta.
(4) Future states, options and scenarios that may result from different actions.

A number of recommendations are offered for consideration by relevant stakeholders.

The underlying rationale of our interest lies in:

(1) The growing concern worldwide on the use of freshwater and the conflicting demands on an increasingly scarce resource. Water was one of the top five priorities for the Johannesburg World Summit on Sustainable Development.
(2) Recognition that natural river flow is a vital element in the sustainability of geomorphic and ecological systems that deliver important goods and services for people, wildlife and environmental quality. The Ebro delta especially is an area of high ecological and economic value.
(3) The need for more informed debate and application of new approaches to the reconciliation of issues of competing water use.
(4) Raising awareness of the artificiallity and inappropiateness of division between ecological/environmental and socio-economic considerations in decision-making. Ecological and environmental benefits generally translate also into strong gains in social and economic welfare.
(5) The need to use ever more challenging cases to demonstrate key lessons for the future in developing strategies and the practice of sustainable water use.

Our assessment provides a considered overview rather than a new empirical study of the likely consequences of implementation of the current specifications in the NHP and identifies other sources of advice and guidance that we consider may have been insufficiently taken into account in its preparation.

1. Executive Summary

The Ebro Delta covers 330 km2, 20% of which is natural areas and the remaining area is agriculture and urban. Rice fields cover about 21000 ha. Natural areas include sandy beaches, lagoons, fresh water, brackish and salt marshes and reedbeds. The delta has a high biodiversity and productivity, supports important fisheries, provides habitat for wildlife, and cleanses water. Important economic activities include agriculture, fisheries, aquaculture and tourism with a total annual economic value of about 100 million Euros. About 8,000 ha of the delta are Natural Park and Ramsar sites, as well as part of the Natura 2000 network of the European Union. The delta is the second most important bird area of Spain.

The Ebro delta developed over the past several thousand years, and the river has successively occupied three delta lobes during the last two thousand years. The delta was relatively natural until the mid 19th century. Rice agriculture during the second half of the 19th century and the first half of the 20th century resulted in the conversion of large areas of wetlands and lagoons to rice fields. Until 1960, deposition of suspended sediments in irrigation water in the rice field resulted in an accretion rate (sediment deposition) of about 0.5 cm per year. Since 1960, large dams have trapped almost all river sediments and there is now a net sediment loss from the delta plain.

There are a number of current issues relating to the Ebro delta that are fundamental to an understanding of the potential impacts of the NHP. These issues demonstrate that the Ebro delta is already under considerable pressure that impairs management for sustainable use.

· Decreased river discharge and almost complete elimination of sediment discharge leading to coastal retreat
· A deterioration of water quality in the river, estuary, lagoons and bays
· Loss of wetlands and other natural habitats
· Salt water intrusion
· Sinking of the delta plain and lack of accretion that is leading to lowering of the delta plain below sea level.
· Predictions of accelerated sea level rise of 40-60 cm within this century.
· Declining fisheries

A number of trends related to global climatic change will make sustainable management of the Ebro delta more difficult and the impacts of the NHP more severe.

The NHP envisages much stronger river regulation by the construction of more dams in the Ebro basin, as well as the diversion of large amounts of water to other basins and new irrigation areas in the basin. The plan does not take full account of the needs of sediment and water management for maintaining the Ebro delta. If fully implemented, the NHP would make it virtually impossible to carry out sustainable management of the Ebro delta in a relative sea level rise scenario. The inevitable result of the NHP will be the deterioration of the lower river and the delta.

We present as examples, two possible scenarios with relative sea level rise (RSLR) as a given condition. One is a sustainable delta scenario based on an integrated, comprehensive plan and the other which is a business as usual scenario is a continuation of recent trends of lower river discharge, decreasing sediment input, sediment export from rice fields, and continued lowering of the surface of the delta plain.

Overall Conclusion and Recommendations

The overall conclusion we have reached is that it would be unsound to proceed with the plan in its present form for the following reasons:

1. Implementation will threaten survival of important habitats and species protected under existing European legislation.
2. The proposed reduction in water flow and consequential further loss of sediment supply puts at risk the sustainability of the entire delta, its ecosystems and human communities. This is particularly so given the ongoing subsidence of the delta and the probability of accelerating sea level rise and climate change.
3. Insufficient attention seems to have been paid to the wide range of guidance currently available from other experiences and arising from obligations under EC directives and International Conventions such as Ramsar and the Convention on Biological Diversity.
4. There is immense public opposition to the plan across a wide range of stakeholders in the affected area of the Ebro Basin and particularly in the delta.

We make the following recommendations. A revised river basin management plan should be prepared for the Ebro and subjected to rigorous public consultation such that the Ebro can be used as a pathfinder for the implementation of the EU Water Framework Directive.

Hydrological management of the Ebro and the other basins should take full account of obligations under the Ramsar Convention, especially in relation to ensuring wise use of wetlands and preventing (adverse) change in ecological character.

More account should be taken of the conclusions and recommendations of the World Commission on Dams (WCD)that provide guidance for management of drainage basins where modifications are proposed.

2. Background and Introduction

2.1 River basins and deltas are intimately connected through the hydrological cycle and must be managed as an integrated functioning unit.

In general, the scientific community considers that management of river basins should take into consideration the functioning of the whole basin; in other words there should be an overall functional approach.

There are several scientific conceptual frameworks concerning the functioning of river basins and deltas. In particular we draw attention to the concepts of the river continuum, the flood pulse hypothesis, and the pulsing hypothesis of deltas. These concepts describe how upstream-downstream interactions in rivers, interactions between rivers and their flood plains, and the diverse interactions among river, delta and sea serve to structure and regulate the functioning including productivity and biodiversity of river basin ecosystems.

In the upper parts of the basin, interactions are strongly from the land to the stream and in a downstream direction. In the lower river basin, bi-directional flows of energy, organisms and material between the river and flood plain become much more important in the ecological functioning of the river. In the delta, strong and continuous interactions among river, wetlands and shallow water bodies and the sea are essential to maintenance of hydrology, biogeochemical cycling, productivity, and biodiversity. The life histories of many species are keyed to active movement among different habitats in the delta. Examples of these species are estuarine fishes like the Fartet (Aphanius iberus) which is endemic to the western Mediterranean coast, or coastal birds like Audouin's Gull (Larus audouinii). Both of these are globally threatened species having their largest world population in the Ebro delta. Sustainable management must be based on this complex ecosystem functioning. Human use of these ecosystems for agriculture, tourism, fisheries, aquaculture and wildlife protection is dependent on but must also recognize and maintain the complex functioning of these ecosystems.

3. The Ebro river and delta

3.1 Its significance for people, wildlife and environmental quality.

The Ebro delta is one of the most important wetland areas in the western Mediterranean. It is valuable both economically and ecologically. It is one of the most important bird habitats in the Mediterranean, and the second most important Special Protection Area for Birds (SPA) in Spain. Part of the delta (about 8,000 ha) was designated a Natural Park in 1986.

The international importance of the natural values of the Ebro delta has been widely recognized. In 1984 it was declared as an area of special interest for the conservation of halophytic vegetation by the Council of Europe. It has been also recognized as an area of European importance for the conservation of aquatic vegetation. More recently (1993), it was included in the list of Ramsar areas and is part of the Natura 2000 network. Wetland area has been steadily reduced from approximately 250 km2 in 1900 to 80 km2 in 1990 due to the conversion to agriculture and other uses.

A total of 330 species of birds have been observed in the delta, of which 81 species breed regularly and another 28 do so occasionally. A total of 55 species are included in Annex I of the Birds Directive of the European Union. Among breeding species, 50 are aquatic, with 40,000 nesting pairs and a mean population of 180,000 birds in winter. The Ebro delta has international importance for breeding of at least 24 species and for migration and wintering of 13 species, and occasionally for 14 more. The fish fauna is also very rich, with 55 species of fishes observed in the delta plain, not including marine species. It is remarkable that there are six endemic species of the western Mediterranean coast of the Iberian Peninsula. It is also remarkable, that there is, in the lower Ebro river, a globally threatened freshwater mussel (Margaritifera auicularia), containing the last viable world population. There are a total of 18 habitats included in the 92/43/EEC Directive for the Conservation of Natural Habitats and Wild Flora and Fauna, from which two of them are of priority conservation and eight are locally endangered.

Agriculture, fisheries, aquaculture and tourism are economic activities that are dependent on the delta, with a total annual economic value of about 100 million Euros. Rice agriculture is the main human activity of the delta (60% of its surface) and rice fields play a crucial role in its economy and ecology. The total production of rice is about 120,000 Metric Tones per year, the third most important of the European Union. An extensive irrigation system delivers fresh water from the Ebro river to the rice fields. In addition to the grain harvest, rice fields play significant ecological roles in terms of over-wintering of migratory birds, preventing saline intrusion, and in biogeochemical cycling such as denitrification. Fish landings at ports influenced by Ebro river runoff are among the largest of the western Mediterranean, with an average of about 6,000 Metric Tonnes per year. Aquaculture is an increasing economic activity, with a high production of mussels and oysters in Fangar and Alfacs bays of about 3,000 Metric Tonnes per year. Tourism has increased substantially since the creation of the Natural Park, and currently the number of visitors is estimated to be more than half a million people per year.

3.2 The Ebro delta is already under considerable pressure impairing the opportunity for sustainable use.

The ecological functioning of the Ebro delta at present is largely dependent on and affected by human activities, especially rice production, as a result of modification of the natural hydrological regime. These activities have already made sustainable management difficult. Under natural conditions much of the water that flowed from the river into the delta plain flowed through wetlands. Much of the water flow in irrigation canals at present (about 45 m3/s from April to September) is through rice fields and bypasses wetlands. High nutrient levels lead to eutrophication and there are pesticide problems. Over several decades, these conditions have led to decreased biological diversity, reduced submerged macrophyte production, and lowered fish and waterfowl populations. Total river discharge of water and sediments is a fundamental driver of the ecological system and essential to the maintenance of structure and function of different habitats in the delta. For example, it has been shown that coastal fisheries catch in the region is related to river discharge.

3.3 Delta Developmental history is inextricably linked to river flow and sediment flux.

The delta that exists today developed over the past few thousand years. Up until the 18th century, the delta increased in area as the river occupied successive channels. There have been three major delta lobes during the last two thousand years. The development of the present delta plain started as a consequence of the last relative sea level stabilization, approximately 5-7000 years ago.

The development of the southern lobe was maximum at the end of the first millenium. By 1500 AD the lobe had already undergone a considerable regression, after the abandonment of the old river arm (Riet Vell). The northern lobe was active by 1580 and reached maximum development by about 1700 (Riet de Zaida). By 1750, the present river channel was active and the delta lobe reached maximum development by the mid 20th century.

After the construction of large dams on the lower river, the river mouth began retreating due to greatly reduced input of coarse sediment (mainly sand). The delta fringe is now wave dominated, tending to smooth the coastline by processes of coastal erosion, transport and redistribution. The existence of spits at both extremes of the outer coast results in a retention of most sand within the system and the total area of beaches and dunes has remained nearly constant.

Already, a significant portion of the delta plain is near or below mean high sea level. Over the next few decades, the most serious geomorphic problem will be the loss of land elevation in the delta plain due to the lack of sediment deposition combined with subsidence (surface land sinking) and sea level rise.

3.4 Need for public debate

The need for more fully informed public debate is central to the emerging new philosophy on sustainable land and water management. It is at the core of the new EU Water Framework Directive as well as in the implementation of the objectives of key International Conventions such as the Convention on Biological Diversity and the Ramsar Convention on Wetlands.

4. Current issues already compromise the future survival and sustainable management of the Ebro delta, and this will be aggravated by the implementation of the NHP

The salient current issues relating to the Ebro delta and implementation of the NHP are as follows:

· Decreased river discharge and virtual elimination of sediment discharge
· A deterioration of water quality in the river, estuary, lagoons and bays
· Loss of wetlands, other natural habitats, and constituent species
· Salt water intrusion
· Sinking of the delta plain and lack of sediment deposition
· Predictions of accelerated sea level rise of 40-60 cm within this century.
· Declining fisheries
· Maintenance of socioeconomic welfare of local communities

4.1 Manifestation of these issues

The main human transformations of the Ebro delta occured in the 20th century. From 1900-1970 most wetlands and some lagoons were recalimed for rice fields, and an intensive drainage system was built to deliver fresh river water to them.

The construction of dams, especially the Ribarroja-Mequinença system, has resulted in great changes in the hydrology and sediment budget of the river. Until the construction of these two large dams in the lower river, there were still large floods and high concentrations of suspended sediments. Sediment inputs to the delta have been reduced as much as 99% and freshwater input has also been reduced dramatically.

Because of the lack of sediment input, considerable areas on the edges of the delta are now below sea level and large scale pumping is now in place. This further results in drainage water being pumped directly to the bays thus further worsening eutrophication and leading to salinity intrusion in the lagoons. In addition, water draining from the rice field contains nutrients and pesticides. Much of this drainage also by-passes existing wetlands and flows directly to lagoons and bays contributing to water quality deterioration. There has been a reduction in fisheries linked to reduced river flow, habitat destruction, and poor water quality. The combined results of these problems threaten the future sustainability of rice farming and fisheries and the maintenance of local communities.

During the pre-dam period, the rice irrigation system led to the enhancement of sedimentation in the deltaic plain with about 50 cm deposited between 1860 and 1960. After the construction of the large dams, sediment inputs to the deltaic plain decreased drastically. The dams decreased large floods and 99% of riverine sediments are trapped behind the dams. Now there is a net export of sediments from the rice fields.

In summary, the history of the present Ebro delta can be divided in three periods reflecting human impacts and management practices in the river and delta. Until 1860, when the first irrigation canal was built, there was a natural delta, with large river floods which spread water with high suspended sediment levels over the wetlands resulting in high sedimentation rates and a large wetland surface area with low eutrophication. From 1860 to 1960, when traditional rice agriculture was developed and there were no big dams in the lower river, moderate and high floods were still frequent, with high sedimentation rates in the rice fields and wetlands due primarily to the irrigation system. The wetland surface was drastically reduced (mostly from 1900 to 1950), but eutrophication was still low because runoff from the rice fields mostly filtered through the wetlands. Since 1960, with the big dams and the development of modern agriculture, the large river floods disappeared and accretion rates decreased drastically. Eutrophication and pesticide pollution increased markedly because of increased use of fertilizers and pesticides and flow bypassing wetlands.

4.2 Recognition of global change is fundamental to sustainable management of the Ebro delta.

One of the key environmental issues that is central to considerations of the sustainability of the Ebro delta and the impacts of the NHP is global climatic change (global warming and changes in precipitation) and acceleration of sea level rise. The international scientific consensus as summarized by the Intergovernmental Panel on Climate Change (IPCC) is that climate is warming and that there will be changes in rainfall patterns. Rainfall has decreased over much of the Ebro basin by about 4% during the past 50 years and will likely decrease further. These further decreases in rainfall imply that the water needs projected by the NHP (water transfer, irrigation and other uses) cannot be met.

Another extremely important result of global change is acceleration of sea level rise that will likely be about 40-60 cm. The Ebro delta, like most deltas, is particularly sensitive to sea level rise because it is subsiding or sinking. Subsidence results naturally from compaction, consolidation and dewatering of sediments and is often enhanced due to human activities such as subsurface fluid withdrawals and oxidation of drained organic sediments. Thus to survive rising sea level, the delta plain must grow upward not only at the rate the sea is rising but also at the rate the delta plain is sinking. The combination of eustatic sea level rise plus subsidence is called relative sea level rise (RSLR). For example, while the current rate of eustatic rise is between 1-2 mm/yr, estimated rates of subsidence in the delta are 2-5 mm/yr, resulting in a RSLR between 3-7 mm/yr. If the surface of the delta does not grow vertically at a rate equal to RSLR, then the surface of the delta will sink below sea level. This means that pumping will become more widespread and continuous, wetlands will become more stressed due factors such as salt water intrusion, and the delta will become progressively isolated from the sea. RSLR is leading to wetland loss, coastal erosion, and salt water intrusion in a number of coastal areas around the world.

Nearly 50% of the delta is presently below mean high water and part of the southern margin of the delta is at mean sea level in an area protected by dikes. Given projections for accelerated sea level rise, about 75% of the delta will be below mean high water in less than a century. As mentioned above, RSLR in the delta is 3-7 mm/yr. Present sedimentation rates in the delta range from 4 mm/yr in the wetlands at the river mouth to less than 0.1 mm/yr in impounded salt marshes and rice fields. The annual sediment deficit in the deltaic plain to offset RSLR is close to 1 million m3/yr. Sedimentation rates in the rice fields prior to the construction of large dams in the Ebre watershed were higher than RSLR rates, ranging between 3 and 15 mm/yr. Presently, more than 99 % of the riverine sediments are retained in the reservoirs and rice fields are losing about 0.2 mm/yr. Thus, under current conditions, the delta will continue to sink below sea level. It is likely that the NHP will further aggravate this trend.

4.3 Realizing that sustainability in the Ebro delta is linked to continued supply of water and sediments

The above considerations clearly show that the Ebro delta is not physically or geomorphologically sustainable at present. The reduction of almost all riverine sediment input has resulted in the cessation of most sediment input to both the delta fringe and the delta plain. There is now retreat of the active mouth of the river and a general reshaping of the delta is taking place. The most crucial problem is the lack of sedimentation in the delta plain. There has been a reversal from a net elevation gain prior to 1960 to a net loss of elevation. Because most of the delta surface will be below mean high water within a century, the delta will become essentially isolated from the adjacent bays and sea.

In essence, the ecosystem will have switched from a system with two-way connections to the sea to one where there is one-way flow of water pumped from the delta plain. At that time a functioning deltaic ecosystem will no longer exist and the system will be strongly non-sustainable. There is also the potential that these forces will likely lead to rice farming to become economically infeasible and the decline of local communities. Examples of the future of the Ebro can be seen in the present status of the Colorado, Nile and Po deltas.

4.4 Benefits of the Ebro river and delta for people

The Ebro river provides water, sediments and nutrients to the delta and coastal marine ecosystems. These fluxes of material and energy are the sustaining base of the main economic activities, landscape, and cultural features of the lower Ebro. As mentioned, rice cultivation, fisheries, aquaculture and tourism, all of which are based on the local natural resources, are the base of the economy of the delta. Moreover, rice cultivation, fishing and hunting have a profound significance in the social and cultural features of the lower Ebro (way of life, literature, gastronomy, etc.), where water is part of the identity of people.

Rice cultivation has an important environmental and economic value in wetland areas, in the sense that it is the best agricultural option. Any other non-flooded cultivation would imply stronger impacts, as dessication, salt stress, more rapid subsidence, and higher water pollution of surrounding wetlands. Moreover, because the rice field is an artificial wetland, it is a suitable habitat for feeding and reproduction of many aquatic birds and fishes. These natural values are the base of an increasing tourism activity, since the delta and the lower Ebro river are visited by more than a half million people every year. Ecotourism and tourist river navigation are two economic activities which are increasing.

5. The Spanish National Hydrological Plan

We do not analyze the needs and purposes of the diversions as indicated in the NHP but we are concerned about the process of decision making and the limited attention to the downstream consequences in the basin of the actions proposed. The NHP envisages much stronger river regulation by the construction of more dams in the Ebro basin, as well as the diversion of large amounts of water to other basins and new irrigation areas in the basin. The plan does not take full account of the needs of sediment and water management for maintaining the Ebro delta. Rivers must be managed to maintain not only a minimum water discharge but also a minimum solid discharge. If fully implemented, the NHP would make it virtually impossible to carry out sustainable management of the Ebro delta in a relative sea level rise scenario. The inevitable result of the NHP will be the accelerated deterioration of the lower river and the delta.

The main goal of the NHP is the implementation of a water transfer of a maximum of 1000 Hm3 per year from the lower Ebro river to the north and south Mediterranean coast. TheNHP law was approved in July 2001, and establishes the following maximum annual values to be transferred to the different basins: 190 Hm3 to the area of Barcelona, 315 Hm3 to the area of Valencia, 450 Hm3 to the area of Murcia and 95 Hm3 to the area of Almeria. The law also establishes a minimum environmental flow for the Ebro river of 100 m3/s (3153 Hm3 /yr), and that the water cannot be transferred from June to September. The law also considers the elaboration of an Integral Plan for the Protection of the Ebro delta, aiming to ensure the special ecological conditions of this area through the mitigation of the negative impacts of the implementation of the NHP.

The NHP also includes an additional list of public works to be implemented during the period 2001-2008, that was previously established in the Basin Plans. This annex includes about 100 new dams and the infrastructure for new irrigation areas (about 400,000 ha), as well as water treatment plants, river canalizations, etc.

Under the NHP, an average of 45 m3/s will be diverted during eight months of the year. This will lead to very little water left in the river in many years. For example, during 2002, the flow of the river has been about 100 m3/s for most of the year, which is the minimum environmental flow established in the NHP law. Moreover, this environmental flow was determined with no scientific basis, without consideration of the needs of water and sediment flows to maintain the delta functioning. The future levels of fresh water input to the sea would almost certainly result in a great reduction of fisheries.

There are a number of assumptions of the NHP that we believe are not valid. These assumptions are that water transfer, dams and new irrigation:
- will not adversely affect downstream ecosystems, their functioning and value to human communities
- will maintain the sustainable use of future desired management options for the lower Ebro, its delta and coastal waters
- represents the widest use of the water resources transferred
- has the general support of society
- takes full account of existing scientific, technical and socio-economic knowledge.

6. Future states, options and scenarios

We consider essential that there is a full analysis of possible and desired future states for the Ebro delta based on a range of options for management of the basin as a whole. This should include the effects of various water transfer options as well as the possibility of enhancing current flows and sediment delivery to the delta. Below we present as examples, two possible scenarios with relative sea level rise (RSLR) as a given condition. We consider it essential that a commonly agreed vision be developed for the desired future condition of the lower Ebro River and its delta and that river basin management should be directed towards that goal.

Future sustainable management of the Ebro delta must take into account sediments trapped in reservoirs, the problem of RSLR and include comprehensive management of freshwater and sediment from the river. The NHP seriously compromises the ability to achieve sustainable management.

A sustainable delta scenario.

This is based on an integrated, comprehensive plan. The comprehensive, active management plan uses river diversions, such as via the irrigation network, to stimulate accretion in the delta plain and using wetlands to improve water quality and provide habitat. A sustainable management plan will include wetland restoration in some low-lying areas, in which gravity drainage for agriculture is no longer possible. These wetlands would provide fish and wildlife habitat and improve water quality. This approach is absolutely dependent on sufficient sediment and water from the river, and should include, where possible, remobilization of sediments trapped behind dams and their transport to the delta. This implies periodic high flows. Currently river diversions are successfully being used for wetland restoration in the Mississippi delta.

The Business as usual scenario.

The business as usual (BAU) scenario is a continuation of recent trends of lower river discharge, decreasing sediment input, sediment export from rice fields, and continued lowering of the surface of the delta plain and will, we believe, result in non-sustainable management of the delta. Given the predictions of climate change, accelerated sea level rise, and the further reductions of river discharge due to the NHP, most of the delta surface will be below mean high water within half a century and will be drained by pumps. There will be salt water intrusion, further deterioration of water quality, and reduced fisheries, due to loss of habitat, poor water quality, and reduced river discharge. In essence, this would mean the loss of the Ebro as a natural functioning deltaic ecosystem. The continued existence of rice agriculture is questionable under this scenario. The Colorado, Po and Nile deltas serve as examples of the future of Ebro dominated by coastal retreat, salt water intrusion, sinking of much of the delta plain below sea level, and isolation of the delta from the sea.

For sustainable management of the Ebro delta, it is crucial to maintain periods with high discharges that have enough river energy to transport as much sediment as possible. The NHP would make it virtually impossible to carry out sustainable management of the Ebre delta, especially in a RSLR scenario.

In summary, sustainable management of the delta requires a continued supply of freshwater to the delta, remobilization of sediments trapped in reservoirs and transport to the delta, movement of sediment and water to both the delta fringe and the delta plain, use of mineral sediments and organic soil formation to increase the rate of accretion, and a balance between agricultural and natural wetland areas to ensure good water quality and maintenance of habitat for wildlife and fisheries. In this sense, the rice irrigation network and the rice fields become integral parts of a sustainable delta. But some rice fields will have to be converted to wetland areas to achieve this balance and the drainage network will have to be changed to ensure that water from the rice fields flows through wetlands before reaching coastal bays. In our opinion, the NHP is incompatible with a sustainable Ebro delta.

7. Conclusions and Recommendations

Resolution of the inherent limitations in the NHP can provide others with valuable guidance on new approaches to water management essential to meet the increasing pressures of people and need to comply with national, supranational and international obligations.


A revised river basin management plan should be prepared for the Ebro and subjected to rigorous public consultation such that the Ebro can be used as a pathfinder for the implementation of the EU Water Framework Directive

The Spanish government has an unparalleled opportunity to develop new thinking on water resource management through compliance with the new Water Framework Directive (WFD). The WFD establishes a new integrated approach for the protection, improvement and sustainable use of Europe's fresh and coastal waters. It came into force in December 2000 and requires member states to transpose the directive into domestic law by 22nd December 2003.

In summary the aims of the Directive are to:

-1. Protect and enhance aquatic ecosystems and their water needs and dependent terrestrial and wetland ecosystems.
-2. Promote sustainable water use.
-3. Reduce emissions of pollutants.
-4. Protect groundwaters.
-5. Mitigate the effects of floods and droughts.

The introduction of broad ecological objectives designed to protect and, where necessary, restore the structure and function of aquatic ecosystems themselves, thereby ensuring the sustainable use of water resources, represents a major shift in emphasis in water policy throughout Europe. It requires controls on the diverse pressures that can adversely affect aquatic ecosystems. The Directive introduces a river basin management planning regime as the key mechanism for ensuring the integrated management of water bodies including groundwater, rivers, canals, lakes, reservoirs and estuaries. Spain has the lead responsibility for the working group on developing Best Practice in River Basin Planning. It is of paramount importance, therefore, that the Ebro be seen as a pathfinder for future implementation of the WFD applying the highest technical standards available. The annexes of the Directive deal with the key technical tasks involved in river basin planning. They indicate the analyses, assessments and monitoring required to underpin the setting of environmental objectives and the design of proportionate and cost effective measures.

We do not feel that the NHP has been adequately subjected to this rigorous but essential interrogation in regard to development of best practices under the terms of the WFD.

The underlying philosophy of the Directive as articulated in Recital (1) is "water is not a commercial product like any other but, rather, a heritage which must be protected, defended and treated as such".

Protection and management of this complexly interlinked biological-cultural 'heritage' requires an understanding of the underlying science especially the functional relationships between the hydrological cycle, land and water ecosystems and human communities.

These interrelationships form the conceptual heart of the Ecosystem Approach to the sustainable management of the world's natural capital and underpins implementation of the key global conventions on biodiversity and wetlands.

We do not consider that the NHP pays sufficient attention to international obligations and recommendations especially in relation to the Convention on Biological Diversity (CBD) and the Convention on Wetlands of International Importance (RAMSAR).


More account should be taken of the CBD and RAMSAR

The responsible authorities should follow decision COP V/6 of the CBD in adopting the ecosystem approach as the tool to deliver broad objectives of the Convention on Biological Diversity (biodiversity conservation, sustainable development and equitable benefit sharing).

The ecosystem approach is the integrated management of land, water and living resources to ensure conservation in a sustainable and equitable way. "It is a method for sustaining or restoring natural systems and their functions and values. It is goal driven and is based on a collaboratively based division of desired future conditions that integrates ecological, economic and social factors. It is applied within a geographic framework defined primarily by ecological boundaries". (Report of the Interagency Ecosystem Management Task Force, 1995)

The ecosystem approach is based on the application of appropriate scientific methodologies focused on levels of biological organisation that encompasses the essential processes and interactions among organisms and their environment. The ecosystem approach recognizes that humans are an integral component of ecosystems (UNEP/CBD/COP4/INF.9, 1998). Implementation of the ecosystem approach is based on twelve principles (See Appendix). We consider that the NHP does not take full or adequate account of these principles.


Hydrological management of the Ebro and the other basins should take full account of obligations under the Ramsar Convention, especially in relation to ensuring wise use of wetlands and preventing (adverse) change in ecological character.

In particular the recommendations of the Ramsar Advisory Mission (August 2001) should be implemented and guidelines followed such as The River Basin Initiative of the Convention on Biological Diversity and the Ramsar Convention (, and the Ramsar Convention guidelines on "integrating wetland conservation and wise use into river basin management" (


More account should be taken of the conclusions and recommendations of the World Commission on Dams (WCD)that provide guidance for management of the lower Ebro River and delta.

Full account should be taken of the global debate on sustainable water use, large dams and the adverse consequences of water transfers. In particular we draw attention to the conclusions and recommendations of the World Commission on Dams (WCD):

The key decisions are not about dams as such, but about options for water (and energy) development. They relate directly to one of the greatest challenges facing the world in this new century - the need to rethink the management of freshwater resources". The dramatic impact of human-induced water withdrawals from the world's lakes, rivers and aquifers is well documented. Total annual freshwater withdrawals have accelerated and in 2000 were estimated at 3800 km3, twice as much as in 1950. The Commission has emphasized the increasing concern about access, equity and the response to growing needs for water. This influences interalia relations between:
- rural and urban populations
- upstream and downstream interests
- agricultural, industrial and domestic sections
- human needs and the requirements of a healthy environment

The challenge is to resolve competing interests collectively and recognizing that "equitable and sustainable solutions will be to the ultimate benefit of all".

The Commission's two objectives were:
a) To review the development effectiveness of large dams and assess alternatives for water resources and energy development.
b) To develop internationally acceptable criteria, guidelines and standards, where appropriate, for the planning, design, appraisal, construction, operation, monitoring and decommissioning of dams.

The WCD Global Review concluded :
- Large dams designed to deliver irrigation services typically have fallen short of physical targets, did not recover their costs and have been less profitable in economic terms than expected.
- Large dams generally have a range of extensive impacts on rivers, watersheds and aquatic ecosystems - these impacts are more negative than positive and in many cases have led to irreversible loss of species and ecosystems.
- Efforts to date to counter the ecosystem impacts of large dams have met with limited success owing to lack of attention to anticipating and avoiding impacts, the poor quality and uncertainty of predictions, the difficulty of coping with all impacts, and the only partial implementation and success of mitigation measures.
- Since the environmental and social costs of large dams have been poorly accounted for in economic terms, the true profitability of these schemes remains elusive.

Applying a balance-sheet approach to assess the costs and benefits, where large inequities exist in the distribution of the costs and benefits, is unacceptable given existing commitments to human rights and sustainable development. The WCD found that alternative options for supply and demand - management were insufficiently explored in most projects.

The Commission grouped the core values that should inform future decisions as :
- equity
- efficiency
- participatory decision-making
- sustainability
- accountability

The WCD has developed seven strategic priorities and related policy principles to guide key decision points in the planning and project cycle:
1. Gaining public acceptance.
2. Comprehensive options assessment.
3. Addressing existing dams.
4. Sustaining rivers and livelihoods.
5. Recognizing entitlements and sharing benefits.
6. Ensuring compliance.
7. Sharing rivers for peace, development and security.

Summary of priority recommended actions

Government should consider how to:

Implement the recommendations of the Ramsar Advisory Mission carried out in the Ebro delta (August 2001).

Apply the principles of the Ecosystem Approach in realizing a common vision for the future management of the Ebro basin including its delta.

Assess the requirements of the Water Framework Directive to achieve sustainability and "good status" of the Ebro waters through integrated river basin planning and management.

Examine the experience and recommendations from the wide range of other available initiatives and processes such as produced by the World Comission on Dams, Ramsar Convention on Wetlands, Convention on Biological Diversity, and World Water Commission.

Eventually use the experience and lessons learned through implementation of these recommendations to formulate guidelines on good practice, appropriate methodologies and indicators of performance that can assist other countries in dealing with similar issues.

Evaluate the appropriateness of the principles of the Ecosystem Approach and report findings to the CBD-COP7 in early 2004.

The Scientific and technical community should examine how best to:

Carry out the necessary further empirical studies to more fully understand the functioning of river and deltaic ecosystems and the effects of the NHP.

Apply appropriate techniques to more fully evaluate the economic and social benefits of a healthy delta complex.

Investigate the existing and potential wider benefits of semi-arid ecosystems unimpacted by irrigation.

Assess alternative solutions to meet increasing water deficits (e.g. reduced demand, desalinization, etc.).

Non governmental organizations should consider the ways in which they can :

Assist in the establishment of dialogue among stakeholders on the ground.

Develop and publish easy to understand technical leaflets, information boards, and briefing notes.

Provide demonstrations and field visits to improve awareness among decision-makers and the general public.

Further encourage water conservation and sustainable land and water management practices.


The 12 Principles underpinning the Ecosystem Approach of the Convention on Biological Diversity

1. The objectives of management of land, water and living resources are a matter of societal choice.

2. Management should be decentralized to the lowest appropriate level.

3. Ecosystem managers should consider the effects (actual or potential) of their activities on adjacent and other ecosystems.

4. Recognizing potential gains from management, there is usually a need to understand and manage the ecosystem in an economic context. Any such ecosystem-management program should: a) reduce those market distortions that adversely affect biological diversity, b) Align incentives to promote biodiversity conservation and sustainable use, c) Internalise costs and benefits in the given ecosystem to the extent feasible.

5. Conservation of ecosystem structure and functioning, in order to maintain ecosystem services, should be a priority target of the ecosystem approach.

6. Ecosystems must be managed within the limits of their functioning.

7. The ecosystem approach should be undertaken at the appropriate spatial and temporal scales.

8. Recognizing the varying temporal scales and lag-effects that characterize ecosystem processes, objectives for ecosystem management should be set for the long term.

9. Management must recognize that change is inevitable.

10. The ecosystem approach should seek the appropriate balance between, and integration of, conservation and use of biological diversity.

11. The ecosystem approach should consider all forms of relevant information, including scientific and indigenous and local knowledge, innovations and practice.

12. The ecosystem approach should involve all relevant sectors of society and scientific disciplines.

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