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L’eau en partage

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Philippe Cecchi

Summary

Testo integrale

1Long marked by their inhospitality because of dreadful parasitoses (mainly sleeping sickness and 'river blindness'), the valleys of the Sudan-Sahel savannah in West Africa have significant, recognised agricultural potential. Related to the upper drainage basins of most if not all the rivers flowing through the region, these inland valleys have often generous soils now re-opened to the population after campaigns to control the major endemic diseases. The WHO Onchocerciasis Control programme, to which an entire generation of Orstom scientists and technicians devoted a large proportion of its energy and work, has thus for some years been in what it referred to as its devolution phase. Priority is therefore awarded today to the cultivation and intensification of exploitation of these valleys. Large and small dams are at the heart of this dynamics.

2From a completely different point of view, lastingly worsening climatic features together with vigorous population dynamics require the implementation of effective strategies for ensuring secure water resources while demand – especially urban – for food products is growing continuously. The region has grids of complex trading networks that are all based on constantly changing production and trading sites. Here again, dams large and small and the farmland that they serve are resources and also clearly identified issues first and foremost by and for the local people who use them.

3Cote d'Ivoire does not escape this general pattern and several hundred reservoirs have been established in successive waves since the 1970s. Although the creation of numerous storage basins has been a pragmatic response to the series of severe droughts that have affected the whole of the sub-continent, the development of savannah areas in Cote d'Ivoire was also aimed at creating attractive production areas to stimulate development in a region remote from the 'Cote d'Ivoire miracle'. This political ambition was seen in particular with the droughts of the 1980s and the building of several hundred dams for pastoral purposes in the north of the country. The exceptional measures then implemented by Cote d'Ivoire had the explicit aim of contributing to create favourable conditions for the sustainable settling of Fulani herdsmen from neighbouring Sahel countries (Burkina Faso and Mali) that were then hit hard by climatic problems. By fostering the subsequent incorporation of the migrant herdsmen in farming systems in northern Cote d'Ivoire, public action attempted to highlight the complementarity of local farming activities and the grazing practices contributed by the Fulanis. At the national scale, this would reduce beef imports by settling these foreign herds and also mitigate local social tension between graziers and crop farmers. Success of the first point depended fundamentally on the second.

4Small but numerous and scattered, the agropastoral dams constructed in the north of the country thus form an infrastructure network whose positive and negative potential are perceived by both neighbouring communities and the management facilities set up by the state. Explicit encouragement was thus provided for artisanal fisheries for both benefiting from the potential fishery resources associated with the impoundments and for generating operating rent for fishermen in neighbouring villages to provide compensation for the land that had been submerged. At the same time, the emergence of especially urban markets with strong demand for hitherto imported market garden produce such as onions led to another form of use of the reservoirs by the forming of a sector centred on irrigated farming. Finally, wherever dams were built, the local communities soon incorporated these new areas into their domestic and artisanal spheres. They adopted behaviour and practices in which the water-bodies themselves, their periphery and the ground water that they help to stabilise have become integral parts of farming systems.

5However, reservations are substantial and take many forms. Firstly, the peremptory affirmations of donors who hold that such developments are not viable because of chronic lack of maintenance are echoed by uncertainties – especially hydrological – with regard to the conditions of sustainability of the reservoirs themselves and hence of the goods and services that they contribute to generating. In the same spirit, although exploitation sustainability is based first and foremost on the interannual reproduction of the resources that they contribute to generating (e.g. fishery stocks), the juxtaposition in both space and time of varied, often complementary and sometimes conflicting activities raises questions as to the evolution of the metabolism of the water bodies (eutrophication, pollution) and the ecological conditions for maintaining their productivity and, more immediately, their quality.

6Secondly, the true benefits drawn from the operation of small dams are accompanied by potential nuisances associated for example with risk behaviour in the context of the proliferation of vectors of water-dependent diseases (especially malaria and schistosomiasis) that may do considerable damage to the value of the use of the facilities. Finally, although dams generate wealth and various opportunities, they also bear or reveal inequalities in the sharing of these benefits and risks. In particular, the initial development objectives of a pastoral sector in Cote d'Ivoire based on the use of the facilities and intended in particular to participate in the improvement of an under-privileged region were replaced by local ambitions marked by the rerouting of these objectives and the reappropriation by neighbouring societies, in various forms, of the developments and their resources at the expense of the official beneficiaries. Small dams thus became arenas for disputes in which the play of power and social tensions – both inter- and intra-community – upset, sometimes very profoundly, the procedures for access to the resources and the conditions of their exploitation.

7A carry-over from the past with the imprint of public action, the small dams in northern Cote d'Ivoire are today a true heritage, but one whose structuring role is still poorly understood or unknown. The gap is a big one in a context of continued use and constant or increasing demand from rural communities for the construction of new facilities. The lack of sometimes even basic information such as the precise number and positions, the lack of knowledge of both their characteristics and functioning, the approximations or gaps in the assessment of their social and economic and also sanitary and ecological impacts are all features that have hitherto made it impossible to establish an objective synoptic picture.

8Ecological and social systems develop together and change reciprocally, especially when the systems concerned are true innovation at the scale of the landscapes and their populations. To be understood, their dynamics require work in which natural sciences and social sciences are combined. The work focused on the small dams in northern Cote d'Ivoire was conducted in this multidisciplinary spirit. The same spirit applies here to the three chapters devoted successively to the area and environments, to their communities and aquatic resources and to the way in which they are used and exploited. Created by man for man, the small dams are above all artificial ecosystems reviewed in the present work. For this, although the report is by definition closely marked by features specific to Cote d'Ivoire, it is hoped that the forward-looking discussion has more general application to all inland valleys zones in Sudan-Sahel rural areas in West Africa.

© IRD Éditions, 2007

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