What does ‘restoring’ rivers mean? 'eco-centric' vs 'human-centric' restoration
For centuries we have been adapting our waterways to use the fertile land of the major river beds for agriculture, to facilitate navigation and promote trade, to produce energy using watermills and dams, and, more recently, for leisure activities. At the same time, to protect against flooding, dykes were built to the extent that Europe's rivers have lost 90% of their flood plains. And, of course, rivers have too often served as an outlet for our waste!
The concept of 'ecological restoration' seeks to correct these impacts and suggests that an ecosystem can be restored to its 'original' or 'balanced' state. One can understand that restoring a castle consists of taking it back to its original state because there is a reference point, from the date of its creation. But when we are dealing with an ecological system that has evolved and changed over thousands of years, the question is more complex: there is no date of creation and we don't know where to place the marker on the timeline! Another approach is to assimilate ecosystems with organisms and to seek a 'healthy state', a rather fuzzy notion akin to that of restoring a functional status before the 'stress'. In both cases 'natural ecosystems' are construed as non-artificialised/humanized. But for socio-ecosystems which have co-evolved for centuries, this reference is not very meaningful as many species have since either disappeared or adapted to the new conditions. When the goal is to remove undesirable aesthetical, ecological, health or economic states, we talk of rehabilitation or reassignment. But then, the 'reference' does not exist and must be defined: what are the criteria to be used and what natures do we want to achieve?
Human actions are most often described by environmentalists as 'degradations', and human use of a system as 'pressure'. Indeed, according to the dominant paradigm of some conservationists, nature is perfect when it is free of human artefacts. Hence, they seek to 'remove' the infrastructures that have been built on watercourses so as to reveal 'wild' or 'natural' rivers... But this calls into question many other issues, such as the safety of local residents, the aquatic ecosystems that have grown over the centuries, and the future of the built heritage. Thus, some ecologists (not environmentalists) differentiate between levels of adapted systems, many of which are functional and should be studied as such rather than systematically considered as 'degraded'. What some have called 'new ecosystems'[i], as opposed to non-humanised systems, contribute to our living environment and also constitute an ecological heritage. This is not to say, of course, that all modified ecosystems are the same, or equally legitimate; indeed, case-by-case evaluations are required. The priority in terms of restoration then becomes clear: limiting pollution and maintaining high environmental heterogeneity, while accounting for an expected reduction in water flows due to climate change.
The large dams that were constructed to produce hydroelectricity and/or store water to protect against flooding, or to supply irrigation networks, together with massive withdrawals, have significantly affected the functioning of rivers: disrupting upstream-downstream continuity, particularly with regard to sediment transport, and greatly shrinking alluvial plains and 'fluvial annexes'. While in the popular imagination a river consists of flowing water, for ecologists a river system is foremost a heterogeneous set of more or less flowing or stagnant sub-systems. A hydro-system is the river together with its floodplain and fluvial annexes, such as backwaters, residual ponds, connected wetlands, etc.
Reclaiming these now largely urbanised areas in order to reintegrate them into the functioning of the river tends to be impossible for reasons of land use and safety. Infrastructures have a role in the current context and, as a rule, there are no plans to remove them in the near future. Neither is there talk of removing navigational facilities or the dykes that protect cities, such as the reservoirs on the Seine River shielding Paris. Lastly, these debates should not allow us to forget the issue of water quality, and, despite great efforts to clean up our waterways, the battle against pollution must remain the priority.
Therefore, the infrastructure discussed above have all been in place for a long time and, with few exceptions, the rediscovery of 'pristine' watercourses is possible only in our imaginations. Thus, particularly in France, attention has been turned to small weirs and their annexes, whether idle/abandoned or still in use, which are said to hinder 'ecological continuity' (i.e. the movement of fish and sediment). One of the objectives is the return of migratory fish (somewhat hastily considered to epitomize aquatic biodiversity) and the movement of trout, despite their being able to cross most weirs (naturally or using fish passes). However, not all aquatic species live in flowing water. Amphibians, for example, prefer stagnant environments and do not mix well with fish. This is also true of many invertebrates that would disappear with the removal of the weirs and associated wetlands, which are known to be rich in species, including those at risk. The removal of these last refuges is in any case only a meagre compensation for the fluvial annexes of the alluvial plain that we have erased, and it condemns part of the aquatic biodiversity that does not live in running water. Despite no assessment having been made of what stands to be gained or lost in terms of aquatic species and ecological functions, the French government has introduced a centralised policy of weir removal.
Supporters of ecological continuity also seem to fail to appreciate the ongoing processes of climate change, which, forecasts suggest, will lead to both more severe flooding and longer dry spells. From this perspective, is it preferable to have a 'natural' dry river or one in which there are still some small water bodies, which, despite their drawbacks, can serve as a refuge during a drought? My experience with other intermittent river systems has taught me the importance of such refuges for the recolonisation of the stream through drift, when the water rises again.
In conclusion, the entire debate revolves around two opposing ecological visions. One can be considered eco-centric, where 'true nature' is non-humanised to the extent that any development is seen as damaging the integrity of the system. The paradigm of nature without humans is the ideal within conservationist circles and is communicated by the concept of 'wild rivers'. Restoration then means erasing every human imprint. This long-dominant vision has been brought into question by those who believe that humans are actors in their environment and that river systems are co-constructed through natural processes and human actions.
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Excellent! I've enjoined very much reading this post - it's very rational and promising for the undeveloped parts of the world, even in Europe. "Eco-centric" approach is frequently against "Human-centric", in fact sustainable human development, imported from the developed world. Much more discussion and work is needed to help undeveloped not to destroy something almost pristine in and around their rivers. In the future, restoration should be very difficult. But, undeveloped world have to design and implement really human, smart development within their environment.
While the basic issues are pretty well explained in the text, it is my opinion that the title and the ending oversimplify the issue.
Here are a few points that reflect my opinion:
1. River systems are like people. They have distinct personalities that reflect many natural characteristics and human ones as well. It’s OK to generalize as long as one recognizes the individuality of river systems.
2. River systems are the ultimate integrators, mainly of hydrology and hydraulics and the pollution factors - point and non-point sources. From the human activity perspective, these are important components of watershed management which should include water resource management. In other words, proper institutes are a prerequisite in order to alter the human induced influences, which are all negative from the river’s point of view.
3. Considering ecosystem services, which are human-centric, the result should strongly suggest an advantage to the “eco-centric” concepts. But…unfortunately the world is not governed by such principles and until that will change, and it probably won’t, we will continue to have river systems that strongly favor “human-centric” concepts with little regard for ecological and environmental issues.
4. As long as major topics such as the carrying capacity of the planet and human values and priorities are not properly addressed, and implemented, the end results will be “human-centric” river systems. That is not to say that all river systems will be homogeneous rather it will depend on many factors, all are probably recognized by the readers. However, that will impose pressure on us humans because we should be trying to imitate nature and with all of the conflicts, we already know that is next to impossible.
5. The overlying issues with respect to the posed question, in both concepts, should focus on the ways to implement policy decisions. In most cases it’s easy to say “we must do…” but who will “do it”, “how” and with “what means" and the answer to that will determine the actions. If dealing with climate change is any indication, my forecast is not optimistic.
How far can we run with this?
In the headwaters of the Tsang-Po, Himalayan glaciers are melting rapidly. Their function, inter alia, is to store precipitation in wet periods (seasons, decades) and release it in drier ones. Would the construction of a large hydropower dam with over-year storage in the eastern part of the catchment be viewed as restoring and preserving the annual flow regime of the Brahmaputra, an important source of water in the dry season for lower riparians, and contributing to sustainable energy resources in Tibet and China?
That's a good question. Let's ask it this way. Rivers fed by melting snow or ice may become intermittent in the context of climate change. Some may even dry up. Hence the dilemma: are we letting nature take its course? In terms of biodiversity protection this is tantamount to accepting losses, including of endemic species? A position that conservationist movements will deplore... Or do we make sure that we maintain a sufficient flow to sustain aquatic life... but then we will have to artificialize the system...
This leads us to revisit our concepts of natural/artificial. And to question the ideology according to which a beautiful river is a river without artefacts.
There is no simple answer to this dilemma. But it must be debated because there will be decisions to be made. They are societal choices that may be different depending on the situations and policies of countries.
We are living in the anthropcene - so not much is 'natural' especially where humans have colonised the planet. So, to consider returning to the 'pristine; is just fantasy. Having said that there is a midway - in which the proper ecological functions of the stream systems can be rejuvenated. In many cases this will be a new balance from what might have the conditions 10 000 years ago.
Currently, as Trustee of a very small area of a large catchment of the river Thame (Oxfordshire, UK) we are trying to do this. In the last few km's before the confluence with the river Thames, we are installing some 'backwaters', some off channel ponds, diverting some of the run of river water through dry channels (man made constructions and considering s fishpass... all 'small beer' in relation to the full length of the river and its catchment - but trying to balance the eco requirements with human needs. Oh, and not forgetting that the local community that lives in the vicinity use these small area of the trust as essential for their daily walks and relaxations - essential in these COVID days!
Excellent subject for debate and worth pursuing this further - practically rather than in theory!
This posting and some of the interesting comments reminds me of the small tank cascades in the Dry Zone of Sri Lanka, where I worked for many years. Beginning before the present era, Sri Lankans created entirely new landscapes based on cascades of small reservoirs constructed on rivers of all sizes to irrigate rice. Some 20,000 such "tanks" were created over the centuries, though they did not all necessarily operate simultaneously. There are detailed formal rules for sharing the water in the tanks, and the paddy fields irrigated by the tank (but no such rules governing the entire watershed or cascade of tanks). They remain a major feature of rural Sri Lankan life today. Similarly, in the "wet zone", Sri Lankans developed systems that capture water from the hills and direct it to paddy fields in the lowlands. In both cases the uplands are also cultivated, and usually have a lot of trees of different varieties. These landscapes are highly diverse and highly productive. In addition, they are aesthetically pleasing; and they provide a habitat for a huge number of birds and other species (a bird watcher's heaven if you will). This man-made landscape is now also the "natural" landscape, though the pre-human ecosystem must have been quite different. Even if Sri Lankans in the future move to towns and cities, abandoning cultivation of these assets, I would guess the Sri Lankan government would do what rich countries have also done: create incentives to preserve this unique agro-ecosystem. They would definitely not try to recreate some mythical pre-human intervention system.
I think this applies to major rivers as well: it is senseless to think we can restore them to some pre-intervention condition. But we can intervene in ways that increase the value of the multiple services they provide to humans.
Thank you for this very positive point of view which shows that the developments are not systematically degrading ecological systems. This raises the fundamental question: is there a reference system and what criteria are used in our value judgements on what a "beautiful ecosystem" should be? I think that there is a strong influence of cultural parameters and the mystical thinking of "paradise lost",
It is the way in which man inhabits the earth that has made it pleasant to live on, says a friend of mine.
Thanks Christian - I agree fully that this is an important discussion, and as mentioned by some respondents, that some so-called "middle ground" or "middle way" is likely the way forward. But what does it mean? And who gets to determine that? And what occurs in one place may not be what occurs somewhere else. The discussion and the way we have the discussion is important in my view - participatory, informed, and respectful, and accepting that it will likely take a lot of time. And importantly, who should be in the discussions? And how do we respond to the 'losers' in any decision?
Does it mean we try to restore highly engineered river systems to something that better supports our riverine biodiversity and provides ecosystem services (benefits from nature) to people? In some cases I'd expect we can and will do that. The biodiversity data is available and in many places it shows what has been destroyed. I also fully expect that in many (most?) cases we cannot go back to some pre-industrial or pre-colonial view of a river, even if we really knew what that was. But it also does not mean that we need to inexorably change every stream that has hitherto not been subject to engineering works, or polluted, or otherwise changed.
In some cases we will and can restore connectivity along streams, even in the big rivers. Progress with fishways to support or reinstate migration paths for fish has occurred, including retrofitting fishways to dams that were built without them, or where they did not work. And dam removal has been occurring - how much or at what cost would be interesting to know, along with why it is occurring. Have a look at the Klamath dam in the USA . And locally in SE Australia we have the much smaller but locally important example of the Winton wetlands restoration following the removal of a dam.
As we face further change in the Anthropocene my expectation is that these discussions will become more complex. As we face the reality of the loss of our riverine and wetland ecosystems, those connected to the rivers through surface and ground water flows, the expectations may change - its not just the biodiversity we lose and mourn, but the benefits. If we continue to degrade these ecosystems we could also lose the carbon storage function of many wetlands and contribute more carbon emissions to the atmosphere, and exacerbate the very problem(s) we want to avoid.
In various discussing these issues I've recently been involved in two exercises that to some may appear as contradictory but which I see as valuable as they raise the contradictions we face when managing our landscapes, and riverine landscapes in particular. One is to question whether the Ramsar Convention on Wetlands (which includes rivers in it's coverage) concept of "ecological character" should be reframed as "social-ecological character" given the role of people in wetlands (and rivers), and the value of wetlands (and rivers) to people, including the built heritage. The other is to support the social-ecological case for the Rights of Wetlands, including the right to exist. The latter being an example of how various people may view and value their river systems. (Both are published in the journal Marine and Freshwater Research with the latter being open access.)
I expect the dialogue on these topics will continue. Best wishes
I understand your point of view but there are very contrasting situations.
For example, the fauna of Lake Victoria is an endemic fauna that is indeed very threatened by pollution. Generally speaking, the endemic species are the most threatened and I am not discussing this. Europe, on the other hand, has experienced several phases of glaciations which have eliminated, in the north at least, all endemic species l The current fauna is a melting pot of species that survived the glaciations, species that reconquered the rivers during warming, and introduced species (1/3 of fish species in France). The network of canals for navigation has created a large exchange area and the opening of the Danube canal to the Rhine some thirty years ago allowed many Danube species to invade the European network. What is the original fauna that has been lost as a result of the developments? Can we speak of degradation in this context of an almost continuous enrichment of species?
There are no examples in France of fish species that have disappeared due to the introduction of foreign species. Nor do I have any examples of species that have disappeared because of small dams. On the other hand, it is a fact that large dams have undoubtedly interrupted the migrations of some amphihaline species, but they have not eliminated the rest of the fauna for all that.
The history of watercourses in Europe has always been a history of change, the disappearance of species and then the resettlement of species. It is the history of life that has never been in balance .
Thank you Max for your comments. I am pleased to see that you are still very active.
I will take a closer look at the work you are reporting. While waiting for a few remarks.
I completely agree that there is no need to « inexorably change every stream that has hitherto not been subject to engineering works, or polluted, or otherwise changed ». However we must recognise that there are different situations depending on climate history but also on anthropisation
Yes, we must be part of this process of interaction between societies and their environment. But then we must change our discourse and no longer talk only about the services provided by nature, which is a totally ideological position. For human societies have also always fought against the harmful effects of nature. By protecting themselves from natural calamities in managing watercourses (storing water against droughts, dams to contain floods, etc.), they have been able to protect themselves from natural disasters. Also by fighting against disease vectors or crop pests. Incidentally, the NGOs have said little about the devastation caused by locusts at the beginning of the year in East Africa... As for diseases linked to wetlands, in Europe they have led to the drying up of a certain number of them in order to eradicate the disease to the great benefit of mankind. The systematic bias to talk only about the benefits of nature shocks me deeply because it is not my experience, nor that of the vast majority of people living in rural areas ? We need to take a more realistic approach to our relationship with nature and not always look at benefits.
From my point of view, nature has no rights ... It is one thing to respect it for ethical or economic reasons, it is quite another to have rights. I refuse to submit to the laws of nature, which could lead us to justify unethical situations.
Thus, having lived and worked in tropical wetlands, and having made a bit of history of wetlands in Europe, I do not share the bucolic vision of Wetlands proposed by the Ramsar Convention... if there are services, there are also dys-services. Wetlands are major producers of parasitic diseases and GHGs, and living conditions in Wetland areas were unhealthy. In this respect, it is necessary to reread the edifying texts of the 19th century in Europe. Malaria was still widespread until the beginning of the 20th century, but mosquitoes are still present and make life hell at some times.
In Africa, living near a wetland means constantly fighting against nuisances and diseases. In simple terms, protecting the wetlands means simultaneously protecting these nuisances. Who is thinking of the local residents who are exposed to these diseases? In fact, Ramsar does not talk about them much and acts as if they do not exist. One logical approach would be to set up public health programmes at the same time. But I remember at our Millennium meetings that a Ramsar official told me that this would be too expensive. A response that shows contempt for local populations... to the right of Wetlands must be opposed to the right to health, that is to say to the "human well-being" that the Millennium talks about. Otherwise we are no longer in a socio-ecosystemic approach, but in a typically ecocentric approach. The supposed rights of the Wetlands must be opposed to the rights to live in a healthy environment. So we are really talking about the socio-ecosystem approach.
Of course, I don't want to say that all wetlands should be eliminated...but to put some logic and transparency back into what are obviously very ideologically oriented discourses.
All the best
Almost all human adaptations of aquatic ecosystems result in a change in biodiversity leading to ubiquitous and hardy species. These hardy species have become more and more common around the world while the unique locally adapted biodiversity dies out. So, from a purely biodiversity point of view, we have to acknowledge that most developments will lower our own resilience as we lose the biodiversity that our futures may depend on.
So for example, a dam may support a new human-made ecosystem that is productive to people and it may even provide new habitat for a few local species. But the bigger picture is that it wipes out most of the local species that were not adapted to living in a reservoir or may not be able to tolerate the very artificial river that develops downstream of the dam – and ultimately they may become extinct as more and more dams are built.
So this is the conundrum. Agreed we cannot hope to return to natural reference conditions, but we need to do everything we can to ensure that developments do not change the local biodiversity and ecological structure as this would ultimately threaten our own resilience. This is the concept of being eco-centric – to try to live within the ability of the ecosystem to support us, rather than development that simply tries to minimise the damage.
The article written by Dr. Christian Leveque is thought-provoking and raises some very basic points both in the context of Developed and Developing countries. Activities related to river restoration vary widely. While in Europe and the USA a large number of rivers are grossly altered. The situation is not so in many of the developing countries. Nevertheless, the water quality of the rivers, particularly in and around urban centres has considerably deteriorated. Improving river water quality as part of the restoration programme is a top priority as opined in this article. It is now prudent to accept that rivers for that matter many of the ecosystems are co-evolved. The role of humans as modifiers of the natural ecosystem must be recognised and accorded appropriate importance. A conservationist's approach to restoring the rivers to their 'Wild self' may not be feasible in today's context to sustain the world population. We can not go back to the pristine condition and what is really the baseline? Sustainable development is anthropocentric and therefore warrants wise intervention not to jeopardise the ecosystem services. The process of development is an experiment. The lessons that we learnt through all these years and the knowledge that we gained must be applied to reorient our actions. The law of nature may provide guidance. Withdrawing from action may not be the solution. Our work in the State of Kerala, India in the matter of river restoration is primarily to detect and limit physical encroachment, bring back biological productivity, identify sources of pollution and combat them at the source including household level sources, wastewater management, and improve flow character. We are trying to create awareness among people about the peril of river degradation and how it will retard the development process. We do not consider the uninstallation of the dams and barrages which are essential infrastructures for the development of our State.
We must accept the co-evolutionary character and hybridity of the river systems and intervene to restore river functions as far as possible.
I would like to speak about the French policy of “ecological continuity rivers”, which is the French variant of a European policy introduced as part of the Water Framework Directive (WFD) in 2000. Under the WFD, the concept of “river continuity” is one criterion among others (notably water quality and ecological health) for improving the quality of water bodies. Since its adoption into French law in 2006, the ecological continuity of rivers has been one of the most significant policy developments affecting rivers in the country. This law describes the ecological continuity of rivers as “the free movement of living organisms and their access to areas, which are essential to their reproduction, growth, food or shelter, the efficient transfer of natural sediment and the correct operation of biological reservoirs (connections especially lateral, and favourable hydrological conditions)”. To put the concept into practice, the removal or adjustment of hydraulic works that obstruct river continuity is privileged. In inventory done in 2018 listed some 95 000 hydraulic works in Metropolitan France. A vast majority of these are small-scale works including weirs, milldams and ford–crossings. Applying the policy of ecological continuity, however, has generated much conflict (opposition by mill-owners to the destruction of their property; unwillingness of residents to alter the waterscapes that they have become familiar with) and scientific controversy (over the scientific validity of the concept itself to the effectiveness of removing hydraulic structures). conflict between different uses and users of rivers is a classic problem in France. This produces three types of problem : struggles between direct uses (e.g. hydroelectricity, cooling of nuclear power plants, irrigation, etc) and indirect uses (e.g. water based activities such as river kayaking, fishing, swimming, aesthetic views) of rivers; inter-use struggles (between hydroelectricity, irrigation and fishing with regard to water quantity or between fishers and hydroelectricity concerning the quality of fish habitat); and, intra-use struggles (between fishers themselves, for example between lentic and lotic water).
The ecological continuity of rivers – and the way it is implemented – in France produces a new type of conflict associated with a new category of the ecological moment; namely non-uses, or non-use values of the river, such as the provision of ecological services, habitat maintenance, etc. Prior to the current cycle, non-use values did not exist as such. This new category of conflict – between uses of the river and non-use values – revolves around the question of the future of existing hydraulic works such as dams, mills, fords, bridge pillars, weirs…
As mentionned in my PhD, the environmental ethics (anthropocentric, eco-centrism and bio-centrism with different variations) could be use as a type of explanation of the 'conflictuality' because they reflect various ways of knowing, grasping and representing rivers. There are multiple perspectives and multiple expectations linked to different ways of accounting for and valuing river amenities. This multiplicity gives rise to difficulties, as shown by the conflict between those who value the cultural heritage of millponds and those who value the natural heritage of free-flowing rivers.
Furthermore, I have an intuition that knowledge about rivers and values are linked. It will be interesting to study this relationship in actors of river management. I noticed this link between environmental ethics and understanding of aquatic environments. It's a possibility that a difference exists between the discourses/paradigm of academics (eco-systemism/socio-eco-systemism) and the reality of managers (wit a action based of mecanicist logic or organicist) = difference of discourses and practice.
Of course everything is up for discussion : this is just some observations during my Phd.
The issue of ecological restoration through the removal of dams is often more associated with large dams (and the 'salmon issue', e.g. in the American Northwest). The heated debate, in France, about small weirs removal (their number is estimated at 80,000) is quite fascinating. Christian mentioned it in his post. Different ecosystems have been created by these (often very old) impoundments but the idea of nature as a free-flowing river, without manmade obstacles, militates for their removal. These aquatic environments and also the historical heritage dimension of these infrastructures are often valued by local populations. Scientific uncertainties about the exact impact of most of these small weirs contribute to fulling opposition. I would be interested to know if a similar debate is observed in other countries.
In most places restoration takes place balancing environmental objectives, economics, and livelihoods. Examples at hand include an ongoing interstate case in the US (Florida Vs. Georgia), and the detailed procedures and limits of Spanish legislation. However, in a recent case in Argentina (Atuel River) the Supreme Court went ahead with an order for restoration without taking into account impacts on irrigation systems to be foregone, employment, income, and social security. The judicial process was not open to render evidence. Cost and benefits for people and economy were not assessed, and a superior overarching environmental priority was stated. People and the economy were of no consideration, and the impacts of climate change on the disappearance of glaciers supplying and regulating water runoffs were not considered. Previous adjudications protecting existing irrigation systems and water rights were ignored. This extreme approach to restoration is ideological, rather than balanced, and is bound to elicit political and social resistance in the future. Irrigation is the basis of economic activity and employment in the area where water rights are to be foregone without compensation.
The Rodman Dam was constructed by the US Army Corps of Engineers on the Oklawaha River, a tributary to the St. Johns River, as part of the Cross Florida Canal Project. It was completed in 1968. The Canal was never completed: President Nixon ordered it stopped under pressure from environmentalists in 1971. But the dam remained as it is. It created the Rodman or Oklawaha Reservoir, covering an area of 5,300 ha, and drowning a large flood plain forest while also engulfing 20 freshwater springs.
Since that time, there have been numerous attempts to remove the dam, with multiple court cases, petitions, etc. In Northern Florida you can easily stir up heated debates by just mentioning this dam. The Oklawaha River is listed as 9th on a list of America’s most endangered rivers by American Rivers, a conservation group.
The defenders of the dam like the recreational opportunities it has created: boating and fishing. They argue destroying the dam would displace many species that now count the reservoir as home and would affect local businesses who provide services to tourists and fishers. The reservoir is considered one of the top bass fishing lakes in the USA.
Ecologists and environmentalists do not buy these claims and want to restore the native fish populations and the natural forest. They argue that there would still be substantial opportunities for fishing – striped bass for example. The water is stained brown, sea lettuce clogs the waterways below the dam, and crushed plant matter floats to the surface and smells.
The two sides are at an impasse. Whose “nature” should prevail? Compromise solutions involving less destruction of infrastructure have been proposed, but the political will and funding are not there. The potential impact of removing the dam is uncertain – it seems unlikely the pre-dam ecology will re-emerge in pristine form. But the current man-made ecosystem also leaves much to be desired.
This very interesting debate on “anthropogenic versus ecological river restoration” is a typical example of a discourse that can be viewed as a dialectical relationship. First introduced by Socrates, the father of Greek philosophy and reported by Plato, a dialectical process means a creative confrontation between two contradictory concepts that may have different logical explanations. In dialectic, a unified approach between contradictory issues may lead to more resilient and even sustainable solutions. This is not a multi-disciplinary view but rather a holistic approach in which benefits and harm to nature induce also benefits and negative effects on man and society. Man and nature although being interdependent and complementary are traditionally analyzed and studied separately. In the University, social and natural sciences are different disciplines and from the anthropogenic view, man is considered separately from the natural world mostly as an opponent rather than as a complement of nature.
In our discussion, benefits result from training rivers and also losses occur in doing so. This apparent dialectical contradiction between benefits and losses from the same action has of course a simple logical explanation: benefits derive from facilitating river transportation or flood protection and negative impacts are due to possible loss of fisheries and ecosystem degradation. We could multiply similar dialectical examples as human interventions to nature, like building dams for energy production or over-drafting groundwater for agriculture may damage transitional river ecosystems and deplete aquifers.
To move from philosophy to applications, the holistic dialectical approach means not just a compromise solution between different technical alternatives, but a resilient solution based on natural laws. To support this statement I will briefly cite two examples from my personal experience: the first relates to the fact that in the northern hemisphere, when tidal forces are negligible, like in the Mediterranean, earth rotation induces Coriolis forces that turn river beds near the shore dextrally. We have respected this bed morphology in the Giofyros River delta, during the flood protection works of Heraklion, the capital city of Creta. See:
and recent floods have confirmed the effectiveness of the measure.
The second example refers to the “magical” hydrological cycle as natural law at the origin of rainfall, the flow of rivers and the recharge of aquifers. In the recent IWRA’s online International Conference on “Groundwater Resilience under Climate Change” that was followed by thousands of participants
the GRACE satellite observations indicated that non-respect by humans of the hydrological cycle law has led to catastrophic aquifer depletion in many areas.
As a conclusion, we can briefly state that nature-based solutions could be a resilient dialectic response to the “man and/or nature” dilemma. See:
I find that the approach to Eco Vs. Human should be tailored to specific cases. The answer cannot be the same in arid and humid areas. When irrigation is developed in arid areas, over years and centuries, any decision should take into account the economic basis and losses of irrigated areas, population affected, investments to be foregone and, of course, the costs (economic, social, environmental) of compromising the sustainability of man made oasis. If they go away cities, infrastructure, and livelihoods (including ability to pay the taxes that sustain public services and utilities) go with them. Planning ex post is much more demanding than planning ex ante. One size fits all does not easily apply here. The magnitude of social damage that may take place is staggering. High planning and assessing capabilities are called for. Simplistic legal and judicial decisions are not up to the task.
Congratulations for this important discussion. I was the Director of Chile for twelve years. As you know the Chilean economy is heavily dependent on water for irrigation, mining, industry, hydro, and urban water supplies. I wish to submit that the decisions related to restoration cannot, and should not, be taken without the consultation, participation, concert and eventual compensation of affected parties. Since water is essential to many social arrangements, and to the economy, affected parties include a wide range of interests, from farmers to urban dwellers, and industrial users. Technocrats and judges may be far removed from such parties, who then have to cope with the consequences of the decisions that technocrats and judges take. This is why the legal systems of arid areas, such as Spain, impose participation of, and concert with, the parties affected by water related decisions. Planning decisions are required to consider the relevance of water for the economy of planning areas.