segunda-feira, 16 de novembro de 2015

Archaeological mitigation at the Alqueva Dam 

Há 15 anos, mais precisamente em Fevereiro de 2000, tive oportunidade de participar activamente num colóquio internacional organizado na Universidade da Flórida, por iniciativa do Prof. Steven Brandt em colaboração com Fekri Hassan (Instituto de Arqueologia do University College de Londres), dedicado ao tema "Cultural Heritage and Dams". Contando com a participação de arqueólogos trabalhando em contextos geográficos e situações muito diversas, consideraram os organizadores que seria importante a divulgação das comunicações então discutidas bem como as respectivas conclusões, através da sua publicação em livro: "Damming the past". Infelizmente, para além do Relatório submetido pelos organizadores à World Commission on Dams, e apesar de ter chegado a estar anunciado pela respectiva editora (Rowman & Litlefield Publishers), o livro em causa, tanto quanto seja do meu conhecimento, nunca chegou ás livrarias. Resta apenas disponível em PDF  e facilmente localizável na NET, o referido relatório. Não havendo muita informação disponível em inglês sobre o projecto arqueológico do Alqueva e uma vez que o texto que então preparei para o "Damming the past" acabou por nunca ser publicado (em contrapartida, publiquei um artigo na ALMADAN, nº11, 2002, "Património Cultural e Barragens", pp74-77, onde refiro a experiência e as conclusões do Colóquio da Flórida), aqui fica o texto original então enviado aos editores.

António Carlos Silva, fazendo a sua intervenção no colóquio de Fevereiro de 2000, na Universidade da Flórida

Archaeological mitigation at the Alqueva Dam (Alentejo-Portugal), the last "big one" of Western Europe

            The decisions, always problematic and sometimes painful, taken everyday by archaeologists all over the world in the exercise of his "metier", specially on salvage archaeology or impacts mitigation, are naturally conditioned by a complex set of factors. There is no big drama on that. It's part of real life. The important, however, is to be so awareness as possible of those factors that interfere at the moment on the options and to be able of assessment, at his own level of work and responsibility, about the different and possibly contradictory values in presence. At last, the archaeologist must be wise on the complex and collective process of making choices or taking decisions. Among some more visible conditions that influences the archaeological work, like the insufficient funding, different political priorities, interference with vital community needs or resources, private rights or interests, the framework of Archaeology as a scientific discipline and a cultural activity, at each moment, is also an important one. I mean by that, for instance, the methodological and scientific approach; the previous archaeological record of the territory, the legal framework of the country; the heritage agencies importance; the social development of the profession of "archaeologist"; the recognition and interest of the public on their own cultural heritage. In fact, it’s not possible to understand the conditions of a specific project, like the Alqueva Dam mitigation process, without a summary reference to the recent transformations and actual context of the Portuguese Archaeology. In other hand, is also important to have some information about the social, economical and political circumstances related to the origin of the multi-purpose water resource plan of Alqueva in order to understand some restrictions on the archaeological scope. Creating the biggest artificial lake in Europe (25 000 ha) and causing an enormous archaeological impact by flooding hundreds of Kilometers of the Guadiana banks on a SW Iberian territory full of History, these old project from the fifties, many times postponed, brought to the Portuguese archaeologists at the end of the XX Century, an extraordinary challenge. Meanwhile, the recent lessons learned at the Côa Valley, with the unique Paleolithic rock art discoveries during the construction of another big dam, had also relevant influence in the Alqueva archaeological project (ZILHÃO, 1998). For one time, the phenomenon of social recognition of the cultural heritage importance, even in the presence of the powerful hydroelectric lobbies, had open some doors allowing new logistical conditions of work for the Portuguese archaeologists. But the economic and social costs of the abandon of the Côa Dam construction at the same year of resuming the Alqueva project, by other hand also limited the capacity of archaeologists having a more important word on the final decision process. In fact, and despite the general consciousness of his large impacts over the archaeological record, the Alqueva Dam was an old demand of the Alentejo region -one of the most depressed of the European Community- and considered the last hope of development. It was, indeed, a social reality that the archaeology couldn't at all ignore.

1. Cultural Heritage Management and Salvage Archaeology in Portugal

            Until the 1970’s didn't exist in Portugal any practice to prevent archaeological impacts related to the large-scale works or vast territorial development plans. During several decades the law, dating from1932 and inspired by the old “antiquary archaeology”, only established some measures of safeguarding legally listed objects and classified sites such as “national monuments” or “of public interest” (Law 20 985, 7/03/1932). In the case of the occasional discovery of archaeological artifacts, "objects" which were deemed to have an artistic or historic value, the perspective that prevailed was the recovery for public collections without any concern for the depositional context. Similarly, within the Public Administration, no agency existed with the competence or the means to safeguard or manage the archaeological heritage. The framework of State concerning “cultural heritage”, a very limited concept at that time, was under control of a consultative “Commission” of notable figures, politically dependent on the National Ministry of Education. In the case of archaeological heritage the law gave to the National Museum of Archaeology (Lisbon) great responsibilities but the Museum had neither the structures nor the means for that task. In fact, archaeological activity, from research to conservation, depended almost exclusively on the work of a few university professors and on the interest of amateur archaeologists, from a great variety of professional backgrounds. Despite the individual merit of some archaeologists and the development of a couple of significant projects, particularly from the 1960’s onwards, the lack of interest of the Portuguese fascist state on archaeological heritage management explains the great weakness in archaeological research during almost all of the 20th century. On the contrary, scientific archaeology had an auspicious beginning in Portugal in the second half of the 19th century which culminated with the holding in Lisbon of one of the most important scientific meetings of the period (1880 - IX Session du Congrés Internacionale d´Anthropologie et d´Archéologie Préhistorique) with very important cultural resonance at the time (FABIÃO, 1999).

            When, in 1974, the dictatorial regime of 1926 to 1974 was toppled, the timid political and economic opening-up attempted by the regime following the death of Salazar (1970) had already had some effect on the development of new archaeological projects. Some of them resulted from international co-operation (such as the “Fouilles Luso-Françaises de Conimbriga” or the excavations by the Deutschen Archaologischen Insituts at the Copper Age settlement of Zambujal) and contributed greatly to the updating of methods and practice for the new generations of archaeologists. The first interventions in “salvage archaeology” also occurs, a new field of the archaeological work developing in Europe at the time, particularly in France. It is the case of the survey project of the Rock Art of the Tejo Valley (Fratel Dam) or the Archaeological Project of Sines (Alentejo). This one, an intensive field survey on the context of a great industrial development project promoted by the State in a rural region close to the Southern coast of the country, represented in Portugal, the first salvage Archaeology project executed under a professional standard (SILVA & SOARES, 1981)

            Despite the political and institutional disruption brought about by the Revolution of 25 April of 1974, it was only in 1980, within the framework of the creation of a new cultural heritage agency that the first public services were instituted with any capacity on "salvage archaeology" approach: the Regional Archaeological Services, with headquarters situated in the North, the Center and the South of the country. These small institutions, inspired by the French model of “Circonscriptions archéologiques”, allowed the professional engagement of several archaeologists, having been responsible for the progressive expansion of the concept and practice of "salvage archaeology" throughout the 1980’s. This phase in the recent evolution of Portuguese archaeology, trying to keep pace with the dramatic economic and social transformation related with the integration into the European Community in 1986, raised the need for new legal instruments. In 1985 a new "National Cultural Heritage Law" (Law 13/85, 6/7/1985) recognized the specific characteristics pertaining to archaeological vestiges, and enshrined, for the first time, the need for the realization of preventive archaeological work in the case of projects which have a significant impact on topography or on the landscape (“In the case of large-scale projects, public or private, it is obligatory to provide budgeted means necessary for the realization of archaeological surveys and eventual rescue excavations through a series of plans, specifically approved by the competent services of the Ministry of Culture, that are judged to be necessary.” Law 13/85, Artº 41, nº2). Although this standard has never been the object of regulation, the obligation to undertake studies of “Environmental Impact Assessment” in the case of planned works, was introduced in the same year of 1985, through an European Community Law (85/337/EC). This environmental legal obligation progressively led to the need for planned assessment of archaeological impacts in relation to a large number of works or projects. Sadly, the Regional Archaeological Services, torn between bureaucratic management problems and the demands for scientific treatment of results from tens of excavations, showed themselves incapable of responding to the ever-increasing needs for fieldwork. The absence of tradition on “contract archaeology” and the professional weakness in this sector, virtually non-existent outside the universities or a few state agencies, explains the situation of crisis. Despite new legal frameworks, and even increasing interest of the public, now we recognized that the archaeological involvement in that period of great economic development that the country experienced in the first decade of EC membership (1986-1995) was very limited causing important losses in the national archaeological heritage. An important dossier concerning Archaeology and Environmental Impact Assessment published in 1995 by a non-governmental organization, denounced the gravity of the situation (RAPOSO, 1995). Based on the analysis of more than two hundred EIA’s reports, the dossier shows that the great majority of those environmental studies had never taken into account the archaeological perspective, very few included archaeologists in their technical teams, rarely the conclusions were based on fieldwork and, even in cases which archaeological impact situations were detected, the recommendations for mitigation were normally ignored. In spite of those limitations, the environmental assessment practice generated new job opportunities for the increasing number of archaeologists graduating from the universities, contributing to the development of salvage archaeology in general (ARNAUD, 1994). At the beginning of the 90’s was founded the first professional association (APA - Associação Profissional de Arqueólogos), and there appeared in the market the first enterprises seeking to respond to the needs of “contract archaeology”. Nevertheless, several problems seriously limited the efficacy of archaeological impact studies in relation to mitigation. We can highlight the disengagement of the environmental and cultural heritage State agencies or the lack of methodological standards regulating this new activity. It is within this context of growing demands of salvage archaeology, faced with the weakness of State agencies, that it is possible to understand the successive grave errors and omissions that surrounded the whole process of archaeology survey in the Côa Dam Project (1990-95), after the amazing Paleolithic Rock Art discoveries. Reacting to the exceptional curiosity of the media, the Archaeological Heritage Management theme encroached on the political debate itself with an intensity not seen before, even at an international level. Thus, the immediate suspension of work on the Côa Dam, was the first major decision of the new government which emerged from the elections of October 1995 (ZILHÃO, 1995). Furthermore, significant alterations in the archaeological structures within the Ministry of Culture were proposed. A new agency was created in 1996 (IPA – Instituto Português de Arqueologia) to supervise archaeology in Portugal with the special purpose of maintaining and updating the archaeological inventory and of participating in the environmental assessment politic including the archaeological impacts mitigation. Although submitting to a different philosophy, the new Institute recaptured the experience of decentralization of the former Regional Archaeological Services, setting up small teams of archaeologists in different locations throughout the country. In spite of certain problems of institutional articulation and the fact that there remain important legislative omissions, the qualitative leap in efficacy in the control of and participation in salvage or contract archaeology is evident today in Portugal, contributing to an expansion within the sector.

2 Cultural Heritage Management and Dams in Portugal

            Considering the lack of others energetic resources, the construction of large dams for hydroelectric power was one of the great political “banners” for the economic development of Portugal in the 20th Century.  But, until the 1980s the assessment of environmental or archaeological impact in public works, was not even provided for. Furthermore, the same thing happened in relation to the direct impacts on people, on their houses and on their land, problems which was easily "resolved" under a politically dictatorial regime (1926-1974). Among others which sadly became well known was the case of the of Vilarinho da Furna, a village with old traditions on communitarian life subject of an important ethnographic study by 1940 (DIAS, 1983) and three decades later submerged under a reservoir. Citing the Portuguese geographer, Orlando Ribeiro, in the preface of a recent edition of that study, “Vilarinho da Furna no longer exists; it did not decline because it was abandoned by its inhabitants but because a dam sank it under the water which drowned smallholdings and houses and even the cemetery situated at the highest part of the village. Not even the dead escaped, and of the living, nobody cared; the derisory compensation payments paid, each one grabbing what he could …”

            In spite of the large number of dams constructed throughout the country, especially in the North where the rivers network is denser, the first case where measures for archaeological mitigation were taken dates only from the beginning of the 1970s, and results from fortuitous circumstances. During the construction of a dam at Fratel on the Tejo river, very close to the frontier with Spain, a group of History and Archaeology students from the University of Lisbon discovered, almost by accident, numerous rock engravings, on banks of schist which the fluvial erosion had revealed, practically at river level. The operation to survey and register them (exact location, photography and molding in latex) that followed between 1971 and 1973, despite the scientific importance of the discovery had an exclusively voluntary character with minimal official involvement. In 1976 there was a first attempt for a planned archaeological survey in the area of a Dam under construction (Alvito-Alentejo). This project involving a small team of archaeologists was designed to serve as a test for future actions, particularly for the already foreseen Alqueva Dam. But the Alvito project was soon abandoned without visible results, due the lack of institutional framework. Maybe, because that failure, in the same year the first construction works was started on the Alqueva Dam without any kind of planned measures on salvage archaeology. But this case will be discussed later.

            Although legislation for environmental impact assessment was only introduced into Portugal in 1985, the establishment of the Regional Archaeology Services, at the beginning of the 80ths, created the conditions for the realization of the first archaeology studies in relation to the construction of dams. In 1982, the Archaeological Service of the North, in collaboration with the University of Minho, started an archaeological survey in the area to be flooded by the Pocinho Dam, on the River Douro. During this survey were discovered and recorded several rock engravings dating from the Bronze and the Iron Age in a site near the area were a decade later would be discovered the Paleolithic Rock Art of the River Côa, a tributary of the Douro (BAPTISTA, 1983). At the same time, a multidisciplinary team completed the work of surveying the area to be flooded by the Torrão Dam, under construction on the River Tâmega, another tributary of the Douro (ABRANTES, 1988). These two examples correspond to a phase in which, despite the absence of specific legislation, the state heritage agencies, normally in co-operation with the state-owned power company, were able to put into practice, minimal plans for impact mitigation. With the publication of the first legislation on "environmental impact assessment" in 1985 (85/337/EC) the responsibility for preventive studies on archaeological impacts began to be progressively transferred to the construction promoters. Thanks to the new legal framework and despite a considerable lack of previous experiences and methodological standards, the demand of those kind of preventive surveys began common. However, the situation was not very clear concerning the financial responsibility for the mitigation phase when it involved the need of large archaeological excavations. That aspect was particularly relevant in the case of large-scale development plans, like the dams construction.

By 1990s, a case was going to assume great relevance to this question contributing to dramatic changes. As a result of a preliminary archaeological survey of the Côa Dam area, a study conducted under contract by the University of Minho, the archaeological importance of the Vale do Rio Côa was registered- without the Paleolithic rock engravings having been identified at this phase- and a deepening of the archaeological study of the valley was recommended. The Cultural Heritage Institute, through the Regional Archaeological Service of the North, assumed direct responsibility for the “Côa Archaeological Project” (1990), establishing an agreement for the research financing with the Dam promoter company (EDP). An archaeological team was formed to carry out the mitigation process, but the fieldwork, including new surveys, was conducted without any external control. The first engravings in Paleolithic style appear to have already been observed in 1992, the year in which the construction of the Dam was decided, but the news of their discovery only came to the scientific community and to the public, like a bombshell, in November 1994. This fact, aggravated by the bitter argument surrounding the attribution of a chronology to the engravings, gave rise to great public controversy greatly intensified by the media. After new discoveries and international appeals, the Socialist Party government, elected on October 1995, decided abandon the Dam project when almost US$150 million had already been invested. The Côa case, whether for the extraordinary way that the media took it over, in particular on television, where it frequently received headline news coverage, or for the high financial and political costs which it occasioned, could not have failed to have important consequences in the realm of the management of archaeological heritage in Portugal. Although the legal framework has not been so far altered, we have observed on the side of the project promoters, public or private, a special attention to questions concerning archaeological heritage. However, given the recognized insufficiency of legislation in this realm, there are worries that the safeguarding of archaeological heritage could be reduced to a situation of only secondary concern. In fact, despite the legal obligation to include the archaeological impacts surveys on the environmental assessment studies, the process control as the final decision, including the determination of the mitigation measures, depends exclusively on the Ministry of the Environment, which, in Portugal, has neither the competence nor the material resources for the cultural heritage management (RAPOSO, 1985).

3. Archaeological management at the Alqueva Dam

3.1. The antecedents

            The idea of constructing a large dam on the Guadiana River, with the aim to exploiting the important though very irregular hydro-power potential of this Southwest frontier river between Portugal and Spain, already has a troubled history of many decades. The plan for this work is to make use of the geomorphic characteristics of the basin of the Central Guadiana and install here a gigantic reservoir (4,150 hm3) as an answer to the serious traditional insufficiency of water in the Alentejo region. This fact, however, implies the drowning of a vast area, approximately 250km2 (25,000 ha, including 3,000 ha in Spanish territory), giving rise to one of the largest man-made lakes in Europe and bringing with it major impacts on the natural, cultural and social environment. The engineering construction presents no special technical characteristics. Its vastness resides in its exceptional future reservoir which, when it is completely full, have an effect as far as the ruins of the 15th century Ajuda Bridge, about 100 km to the NE of the dam wall. For several reasons Alqueva Dam is currently far from reaching a consensus by the Portuguese public. Nevertheless it represents a long-standing social aspiration of the Alentejo, one of the poorest regions in Europe, in the grip of serious problems of depopulation and economic depression. It is particularly stressed by the project opponents, in the face of the chronic problems of the agricultural surpluses of the EU, the inadequacy of the irrigation development plan, formulated fifty years ago, and based on a forecast for the intensive exploitation of fertile, well-watered land. The main argument on the part of its defenders, however, is the strategic importance that large reserves of water will assume in the 21th century, in particular in the southern regions of Europe.

The Dam project, when formulated in the 60ths, had planned no previous archaeological studies despite the gigantic size of the flooded area and the aware warnings of some archaeologists. In1976 the Dam construction began without any kind of archaeological mitigation activity. Only in 1979, after a temporary suspension of the project -that lasts during fifteen years- the University of Evora made a first attempt of archaeological assessment. Supported only by bibliographic data, this preliminary study proved the archaeological relevance of the territory menaced by the Alqueva Dam and the need of an appropriated mitigation plan. Despite that study limitations it led to important changes in the official planing of the Dam. In 1980, reflecting the renewal of the policy for the management of cultural heritage, the Council of Ministers, in the absence of any legal framework for the situation, decided, through a specific Resolution (Nº 395/80, 21/11/1980) that the archaeological studies considered necessary at the Alqueva territory should be undertaken, and that the respective costs should be provided by the Dam budget. However, this ministerial "resolution" had no immediate consequences because the Alqueva Dam project was facing new delays caused by financial difficulties. In 1985, on the eve of Portugal’s entry into the European Community, and in the expectation of financial support, the Alqueva Project was submitted to a first Environmental Impact Assessment study, in accordance with the European Directive 85/337/EC. The archaeological component of the study, a preliminary field survey of the 250 km2 project area, permitted to record about two hundred sites of archaeological or ethnographic interest in the area to be flooded. It also proposed, as mitigation process, the deepening of the surveys and the execution of a large number of archaeological excavations (MASCARENHAS, 1986). Nevertheless the political indecision relative to the Alqueva Project, was not favorable to the fulfillment of the archaeological recommendations of the EIA. Only in 1989 and 1990, was possible to undertake new field surveys directly promoted by the Regional Archaeological Service. Seeking to cover some of the most evident gaps in the archaeological record it was then possible to enlarge around 50% the available database. But, for lack of funding, the fieldwork was once again cancelled without the objective of an integral survey of the zone having been reached (SILVA,  1999).

            Responding to the Portuguese request of European financing for the Alqueva Dam, the EU Commission imposed to the Portuguese authorities new environmental studies, including the territory to be reclaimed by the Irrigation Plan and the Spanish lands menaced by flooding. The new studies were contracted between 1993 and 1994 and for the first time the archaeological impacts assessment included the areas situated downstream from the Alqueva dam. Although those studies were mainly based on bibliographical data, the conclusions also pointed to a high level of negative impacts, stressing again the need for the deepening of the archaeological work. At last, in 1995 the Portuguese Government decided formally to restart the construction of the Alqueva Dam, establishing, for this purpose, a public company, EDIA (Empresa de Desenvolvimento e Infraestruturas de Alqueva). At the time the Government, in an election year, was under strong criticism from the archaeologists, ecologists and the public in general about the Côa Dam controversy. In that political context, the importance of the archaeological heritage of the Alqueva area could not be ignored, and in May 1996 an archaeological department was created within the new company. The priority of the new service was to improve the archaeological database concerning the area to be flooded. With that purpose, the field walk was restarted immediately. At the end of 1996, the surveying phase was considered concluded and the organization of all of the records and information accumulated since 1985 having been completed, including the archaeological material collected during diverse phases of the survey. The archaeological data were completely published at this time and disseminated at an archaeological conference (November 1996), organized in order to discuss the mitigation strategy and to prepare the archaeological management plan (SILVA, 1999).

3.2. The Mitigation Plan

            By the end of 1996 the cultural heritage database of the Alqueva area had reached 1,300 records, including archaeological sites (from Pre and Protohistoric, Roman and Medieval times), ethnographic structures (including about one hundred water mills) or relevant artifacts finds. But by some criteria, such as the nature of the remains, their cultural or scientific potential, or their topographic position in relation to the future reservoir or others facilities and infrastructures, only about one third of those sites were selected for some kind of mitigation trough the principle of "data recovery". Even so, a gigantic task had to be faced, considering the short time, about five years, before the beginning of the inundation process. Besides those obvious difficulties, "many sites versus short time", others problems also demanded an adequate strategy. I emphasize, for instance, the recent tradition and weakness of contract archaeology in Portugal and the high probability of new and important archaeological discoveries during the mitigation process, demanding capacity of organizational adaptability.

Organization and strategy:
i. Centralized co-ordination of the mitigation process through a light but experienced archaeological staff, a division within the Environmental and Cultural Heritage Department of the public company responsible for the Alqueva Project (EDIA); this division has the scientific support of an independent scientific commission;
ii. Co-operation and direct communication between the EDIA archaeological division and the archaeological agency within Ministry of Culture (IPA) based on a special agreement, lessening the weight of the archaeological bureaucracy and making easier not only the permission and validation processes but also the eventual planning changes;
iii. High capacity to manage great quantities of geo-referenced data, including the archaeological and topographical features, supporting the planing and decision making process;
iv. Resort almost exclusively to "contract archaeology", in different ways and forms, (including private firms or public institutions) to develop research projects previously identified by thematic or geographic criteria, or to execute specific tasks, like geophysical surveys or other scientific works;

The Plan
We have considered three different levels of intervention, also corresponding to different mitigation approaches:

i. Projects directly related with the construction work, within the "reservoir" area or along others infrastructures or facilities, like the new roads, irrigation canals, or even a new village construction; others projects interacting with specific sites demanding a special approach like the legal classified monuments;

ii. Pluri-annual archaeological research projects, based on chronological and territorial criteria, focusing in a certain share of the archaeological database, designed and executed by autonomous teams contracted on a public application basis; in a first three years round – at several situations prolonged to four or even five years- the teams have given priority to the field work according the vulnerability and relevance of the sites (surveying, recording, sampling and excavating); meanwhile the contracts also foresee the costs for future material analysis and publication;

iii. Protection or adaptation of relevant sites or structures for the flooding effects and according the local communities interests, design of cultural heritage projects for selected sites or monuments along the future reservoir banks; at last, museums facilities planning, compensating the loss of significant cultural resources;

3.3. The field work:

            The "Mitigation Plan" was approved by the Ministry of Culture in June 1997 and guaranteed the financing by EDIA it was thus possible to begin the first mitigation actions, namely the intensive archaeological survey in the areas affected by the construction works. Curiously, the validation by systematic sounding of surface vestiges at the chosen emplacement of the village projected for resettlement of an old village located within the future reservoir, led to the discovery and excavation of a roman rural house (III-IV century AD). Still in 1997, systematic data recovering by excavations or other methodological means, begun on more relevant sites, like the pre-historic "Megalithic enclosure of Xerez", the Calcolithic fortified settlement of "Porto das Carretas" or the roman site of "Castelo da Lousa".

Several bureaucratic problems delayed until the beginning of 1998 the start of the majority of the projects that involved a call for public application At last, on March 1998, sixteen archaeological contracts were signed with independent teams. With these contracts, together totaling about 4 million US$, the Dam company committed itself to financing, over a 3 year period, a high number of archaeological excavations on a large number of sites, previously identified in the Mitigation Plan. However the projects evolution would have to depend on the field observation, archaeological testing or on research design, in order to take the best scientific profit of an exceptional situation. This contract malleability permitted successive goals and financial adaptations and one third of the projects were prolonged to 4 years, and two projects even to 5 years.   Naturally, the financial value of the contracts varied somewhat, between about 50,000 US$ and 500,000 US$. But the strong and exceptional investment of public funds demands an increase in knowledge about the past of the territory to be “lost”. For that purpose, and besides all these field activities, the study of the materials and the publication of the final reports, with the financing also guaranteed by EDIA, are already on way with the signature of several new contracts. Only with the cultural and scientific data dissemination, the mitigation process is really finished. 

3.4. Mitigation over the Spanish border

Contrasting with the Roman and Islamic times, the Guadiana river became, partially, a border between the new Christians kingdoms of Portugal and Castilla in the XIII century AD.  Besides evident reflexes on the archaeological record of the Alqueva territory resulting from dramatic changes on the settlement strategy, before and after the frontier dawn, this geopolitics feature has also consequences on the project management. In fact, about 12% of the planed reservoir is today Spanish territory and, according to the EC laws and the Portuguese-Spanish treaty on the commons water share, Portugal is responsible for the whole Alqueva impacts mitigation costs. Nevertheless and despite the awareness of the cultural impact dimension on the Portuguese side, only in 2000, after 3 years of conversations it was possible to promote a general archaeological survey of the Spanish territory menaced by the flooding and an area, for geographical reasons, up to that date forgotten by the archaeologists. The strange delay could be justified above all by diplomatic handicaps. As long as relationships between the two countries depends on international affairs, the cultural resources management on the Spanish side is under the jurisdiction of the Extremadura Regional Government. Meanwhile the 2000-year survey conclusions permitted to discuss and prepare a specific two years mitigation plan (2001-2002) that started with the systematic record of an important Pre-historic rock art site (Molino de Manzanez) conducted by a Badajoz Museum team. But several others archaeological sites were selected for sounding or excavation, like a new Calcolithic settlement (San Blas), a large roman site (El Pico) and an Islamic village (Castillo de Cuncos). The watermills of the Spanish border, similar to them of the Portuguese side were also object of record. 
Table 1- Mitigation projects in the “reservoir” area (1997-2002)
                    (Portugal & Spain)
Cultural theme
 sites a
2     (1) b
37 (15%)
Recent Prehistory /settlements
6     (1)
45 (19%)
Recent Prehistory/megaliths
17 (7%)
Prehistory / Rock Art
2     (1)
            4 (2%) c
24 (10%)
6     (1)
45 (19%)
4     (1)
53 (22%)
Old Military structures
9 (4%)
Sheperd shelters
6 (2%)
Water mills
2     (1)
                        -           d

ª     - sites tested or partially excavated;
b      -  projects on Spanish territory;
c   -   systematic survey and record
d -      systematic survey without excavations (about 100 ethnographic structures recorded)

Table II -Evolution of the archaeological record of the Alqueva reservoir

4. The Alqueva Dam lessons

            The flooding process started, on a slowly way, in February 2002 but it is very early to make an evaluation of the results of the process, since it is still underway. Some projects, namely in Spain, are finishing the archaeological excavations (Summer 2002),  while the others are already preparing the final reports publication. But we can make a short list of ours present impressions about the scientific developments, the cultural resources management new practices, and, at last, the social losses or profits.

The scientific developments

It is obvious that, despite the inevitable loss of a significant part of the potential archaeological register of the area, which will be flooded, under normal conditions and for exclusively scientific motives, it would never have been be possible to realize, in this interior zone, an investment in archaeological research of this kind and dimension. And the surveys and excavations discoveries, even before the additional laboratory research, can be considered extraordinary. We can now objectively speak about Middle and Upper Paleolithic settlement at the Guadiana basin. Besides several sites presenting lithics remains it’s confirmed the Upper Paleolithic classification of some engravings among the large Rock Art Complex recorded at the Guadiana edges. But the most significant discovery on Ancient Prehistory is dated from the Epipaleolithic period. An unique site, Barca do Xerez, conserving habitat structures and fauna remains in a rare state of preservation was found on the Guadiana edge, bringing new data for the understanding of the economic and social changes that had open the way to the Neolithic process along this interior territory (ALMEIDA, 1999). The Alentejo Megalithic phenomenon was well known after many years but on the contrary the settlements of the dolmens builders were almost a mystery (GOMES, 2000; OLIVEIRA, 2000). With the systematic surveys of the Alqueva territory, the numerous excavations of Neolithic and Calcolithic habitats, (GONÇALVES, 1999; VALERA, 2000; 2001) and at last, the discovery and record of a large Rock Art Complex, on his most impressive part cultural and chronological related with Megalithism, that situation has changed dramatically allowing new explanation models for the Recent Pre-historic settlement strategy. Alongside the Guadiana river, at the top of the hills, several fortified sites dating from the last Millennium bC were recorded but no one was been object of archaeological research before. The excavations made by two different teams, brought new and relevant data about the Bronze and Iron Ages at the SW of Iberia (ALBERGARIA, 2000). The Alqueva territory is not far way from the old town of Emerita Augusta, the capital of the roman province of Lusitania, established by the first Emperor near the Guadiana river. But only one site, "Castelo da Lousa", was recorded and partially studied (WHAL, 1985). The systematic surveys and the numerous excavations conducted at the project area by four different teams revealed us an unexpected and dense network of roman farm houses (GOMES, 1999; LOPES, 2001). The archaeological record shows that this settlement density had last during the medieval times, contrasting with the actual poor demographic situation, a consequence, among others reasons, of the XVII and XVIII century frontier wars.

“Cultural Heritage Management” practice

For the first time in Portugal, it was possible to integrate amid the Dam Company organization (EDIA) an archaeological staff reporting to the Administration board. That innovation brought evident advantages, namely direct access to planning activity and other vital information. Although a very light structure, the archaeological division had the adequate skills to identify the mitigation priorities, the capacity to choose the convenient solutions and the financial means to contract well trained archaeological teams. However, it is now evident that a distribution for a longer period of a so big investment on money and field work would have had great scientific and magement advantages. The time handicap, resulting from the political and economical hesitations surrounding the Dam project, reflected negatively in the mitigation process, reducing the field research phase to a short period of 3 years, at last prolonged in some situations to 4 or 5 years. Today it seems to us that it would have been very advantageous to have proceeded the current archaeological phase through at least two years of intense survey, supported by tests, soundings or geophysical methods (CZAPLICKI 1989). Any way, considering the urgency of developing a plan for rescue excavations, which was also essential to inform financial negotiations, and conscious about the limitations of our archaeological knowledge of a so gigantic territory, our main concern was improve and organize the field walk database. In consequence, we implemented an open information system, able to be permanently updating with new data, and a management strategy adaptable to eventual changes on the working plans. The integration of the spatially referenced archaeological data in a Geographic Information System, with access to different layers of digital information, including accurate aerial photography survey of the project territory, allowed us to control permanently the sites information, after his position in space (SILVA, 2001). Crossing the archaeological information with the project development digital plans and other spatially referenced environmental data such as elevation, vegetation, hydrology and land use, we can have a first but very rigorous assessment of eventual impacts. Today the GIS are essential tools as decision support systems in cultural resource management and rescue archaeology (ALLEN, 1990). But this is especially true in territorial multipurpose development plans leading with large amounts of archaeological information, as the case of Dams. Even not using in the Alqueva case predictive modeling for site location studies, the use of GIS, integrating all the information disposable at the moment, is revealing to be very useful for locate areas sensitive to the presence of archaeological sites in advance of development, avoiding those areas or planing the archaeological mitigation.

At the Alqueva Project we also tried to go far beyond the traditional concept of “archaeological salvation by the scientific record”. Anticipating the flooding effects we have prepared and executed a plan for damage minimization. Considering the cultural relevance of the archaeological structures, their localization on the dam reservoir, or their nature, we have designed different approaches. Simple reburial of the excavated sites, trying to reproduce the former topography of the soil; reconstruction of the original “tumulus” that in Pre-history covered and protected the “dolmens” (Figure 6); or in a very special case - maybe an world premiere- an experimental project, conserving for an uncertain future the architectural remains of a republican roman site, “Castelo da Lousa”, under a gigantic “sand sarcophagus”.(Figures 4 e 7). At last, some archaeological features and, in one exceptional case, an entire monument, the “Xerez Cromelech”, were removed for future museum care (Figure 3).

Social losses and profits

            Despite the dimension of the Alqueva archaeological scientific damages, we didn’t feel no special concern about it from the local population. With very few exceptions, like the monumental roman "Castelo da Lousa" or the "Megalithic Enclosure of Xerez", both publicized for tourism purposes, the rich archaeological resources of the area were practically unknown until the Alqueva surveys. By other hand, on the last 50 years, especially after the economic ruin and abandon of the numerous water mills of the Guadiana, the local inhabitants begun loosing all the traditional connections with the river, on the economic as well on the cultural field. Today the last millers are dying, and with them the memory of a complex system of life is vanishing forever, even before the coming flood.  The few fisherman with small and ancient but well adapted boats that insist on his traditional work, are also very old and upset with the water pollution or the EU rules. In conclusion, on the people opinion, the biggest social impact of the Alqueva Dam results mainly from one village inundation obliging the resettlement of about 400 persons. For that reason a new village is under construction, trying to reproduce the original urban structure but improving the quality of life of the inhabitants. A museum constructed between the relocated cemetery and the reconstructed sixteen-century village church will try to keep the memories of the submerged village. But, in spite of the careful and expensive resettlement program, nobody at the Luz (Light) village seems to be happy with the perspective of the forced house move that had begun in the 2002 Summer.

            Although the large majority of the local population is not aware about the material vestiges of their own cultural heritage, or by, other words, about their own archaeological resources, we think that is the archaeologists responsibility to explain his job and to justify the large funds, supported by the taxpayers, spent on Archaeology. So, every phase of our project has been object of some kind of information dissemination among the public in general, sometimes with the support of the mass media: we can refer the organization of two archaeological expositions, the edition of thematic brochures and posters free delivered on the schools, and even the production of two television programs in co-operation with the national TV network. For a most specialized public we have organized three archaeological conferences (1996, 1999 and 2001) always with a large and interested attendance, especially from archaeology students. We have also edited the two first volumes of a new scientific collection (Memórias d'Odiana, according to the Latin and Islamic names of the Guadiana River), created exclusively for the Alqueva final reports dissemination. 

Last lesson

            In spite of the so far recognized success of the Alqueva Archaeological project, there is something that we have learned and nobody can ignore. On this kind of big public works, with a so large territorial impact, however the money and work spent on archaeological survey, more we can, at last, be aware about the real dimension of the scientific data losses and cultural heritage damages. Even the exceptional dimension of the research investment, at many field archaeological actions we feel only have opened thin windows to the sites knowledge, indeed. Rarely we have had the opportunity to cross new scientific doors... In conclusion, in spite of the job opportunities created for tens of archaeologists and technicians far away from the big cities; in spite the many lessons learned on the archaeological management practice; and in spite the effective improvement of the Alqueva territory past knowledge, we can't, in conscience, recommend our experience elsewhere. Maybe the best way to avoid the huge cultural heritage losses due to big dams is to avoid big dams, if socially acceptable.

Post Scriptum

Subsequently to the redaction of the first draft of this paper, several open-air locations with prehistoric rock art (most of them presenting Neolithic engravings, recording anthropomorphic, zoomorphic and abstract motifs) were identified in the territory to be flooded by the Alqueva Dam, first in the Spanish sector of the reservoir (October 2000), after also on the Portuguese sector (April 2001). This event, used by anti-dam environmentalist groups, encouraged by the media curiosity about a so-called “second Côa affair”, had brought some national and international controversy namely among the archaeological community. Of course, the situation deserves here a short explanation. As it’s common on this kind of archaeological projects acting in large territories, it was expected the possibility of new and significant finds during the mitigation phase. So, different contracts signed with the archaeological teams included a component of further survey that occasionally made possible new discoveries of major sites for some cultural periods (see graphic bellow) and later object of some kind of mitigation work, increasing the archaeological mitigation budget by 30%. But, showing other obscure purposes besides the archaeological heritage interest, the promoters of the “Guadiana rock art safeguard” campaign, at any other former situation had demonstrated public concern. Even after the calm down of the minds, we must stress the following facts:

a) In absence of significant evidences after different survey projects, the Mitigation Plan publicly discussed and approved by an independent scientific comity in 1997, didn’t foresaw new specific work on this matter.
b) The rupestrian art finds, both on the Spanish or the Portuguese sector, are constituted by isolated rock panels, sometimes forming large sets, lying in the river bed and regularly under water in the winter. The great part of the finds is located on the tail of the reservoir, a section of the Guadiana with some recognized gaps on the archaeological assessment phase. In fact, a new field-walking project on the Spanish territory (10% of the Alqueva reservoir) was just beginning (after years of “diplomatic” talks) when the first discoveries of rock art were made. By other hand, the North sector of the Portuguese part was surveyed in the 80ths and, by different reasons, namely the shortage of time, was out of the large field revisions made by our own survey team in 1995/96 (see Table II).
c) In both situations, a good interaction between the heritage administration (IPA- Portuguese Archaeological Institute and the Direccion General de Patrimonio de Extremadura, Spain) and the archaeological coordination of the Alqueva Project favored an open and quickly public circulation of all relevant information but also an immediately field research reaction. Two big teams of experimented archaeologists, directed in the Spanish sector by a specialist of the Badajoz Museum and in the Portuguese sector by the Director of the CNART (Centro Nacional de Arte Rupestre), had made new specific and systematic surveys on the Guadiana River and his tributaries and achieved the archaeological record of all the engravings panels in the meantime recognized. The fieldwork was conducted during several months in 2001 and both teams had finished their work some months before the flooding process start (February 2002). Now, like the others archaeological teams involved on the Alqueva project, they prepare the final reports for proper publication.


ABRANTES, J.R. (1988) – Património etnográfico afectado pela Barragem do Torrão, IPPC, Lisboa

ALBERGARIA, J.; MELRO, S.; RAMOS, A. (2000)- Escavações arqueológicas no Castelo das Juntas (Moura) ERA Arqueologia 1, p.38-51, Lisboa

ALLEN, K.; GREEN S.; ZUBROW, E. (1990)- Interpreting Space: GIS and archaeology. Taylor & Francis, London

ALMEIDA, F.; MAURÍCIO, J.; SOUTO, P.; VALENTE, M.J. (1999)- Novas perspectivas para o estudo do Epipaleolítico no interior alentejano: notícia preliminar sobre a descoberta do sítio arqueológico da Barca do Xerez de Baixo, Revista Portuguesa de Arqueologia, V.2, nº1, p. 25-38, IPA, Lisboa

ARNAUD, J. (1994)-.A componente arqueológica no processo de AIA em Portugal, in Avaliação do Impacte Ambiental. CEPGA, Lisboa

BAPTISTA, A. M.(1983)- O complexo de gravuras rupestres do Vale da Casa (Vila Nova de Foz Côa) Arqueologia, 8, p.57-69, GEAP, Porto

CZAPLICKI, J. (1989)- "A contractor's perspective of two approaches to cultural resource management in Arizona" in Archaeological Heritage Management in the Modern World.  edited by H.Cleere. UNWIN HYMAN, London

DIAS, J.(1983) - Vilarinho da Furna, Uma aldeia comunitária, IMPRENSA NACIONAL, Lisboa

FABIÃO, C. (1999) – Um Século de Arqueologia em Portugal-1, Almadan, IIª Série, 8, p.104-126, CAA, Almada

GOMES, M.V.( 2000)- Cromeleque do Xarez, a ordenação do caos, Memórias d’Odiana, 2, EDIA, Beja

GOMES, S.; BRAZUNA, S.( 1999)- Ocupações romanas da margem direita do Guadiana, Almadan, IIª S., 8, p. 207-209, CAA, Almada

GONÇALVES, V. (1999) - Reguengos de Monsaraz, territórios megalíticos, MNA, Lisboa

LOPES, C. (2001)- Mundo rural em Pax Julia, estrutura e funcionamento, ERA Arqueologia, 3, p. 132-149, Lisboa

MASCARENHAS, J.; SOARES, J.; SILVA, C.T. (1986). O património Histórico-cultural e os Estudos de Impacte Ambiental: proposta de metodologia para a avaliação do impacte de barragens. Trabalhos de Arqueologia do Sul 1, p. 7-16, Évora

OLIVEIRA, J.( 2000)- A Anta da Fábrica da Celulose, Memórias d’Odiana, 2, EDIA, Beja

RAPOSO, J. (1995) Avaliação de impacte ambiental e património cultural. Almadan, IIª S. nº4, p. 60-86, CAA, Almada

SILVA, A. C. (1999)  - Salvamento Arqueológico no Guadiana. Memórias d´Odiana 1, EDIA, Beja

SILVA, A. C.(2000) - Inventário arqueológico-actualização,  Memórias d’Odiana 2 , EDIA, Beja

SILVA, A.; PERDIGÃO, J.(2000) – Aplicação dos Sistemas de Informação Geográfica à minimização dos impactes arqueológicos, Actas do 3º Congresso Peninsular de Arqueologia, Vol. X, ADECAP, Porto

SILVA, C. e  SOARES, J. (1981) – Pré história da Área de Sines, Gabinete da Área de Sines, Lisboa

VALERA, A. (2000)- Moinho de Valadares e transição Neolítico Final/ Calcolítico na margem esquerda do Guadiana: uma análise preliminar. ERA Arqueologia, 1, p. 24-37, Lisboa

VALERA, A. (2001)- A ocupação pré-histórica do sítio do Mercador (Mourão). ERA Arqueologia, 3, p. 42-57,  Lisboa

WHAL, J. (1985) – Castelo da Lousa, ein whergehoft Caesarish-Augusteischer zeit, Madrider Mitteilungen, 26, p.149-176, DAI, Madrid

ZILHÃO, J. (1998) The rock art of the Côa valley, Portugal. Significance, conservation and management. Conservation and Management of Archaeological Sites, V.2, nº4, p. 193-206, James & James, London

Sem comentários:

Enviar um comentário