The water control is an essential element to adapt to climate change . “We must necessarily find adaptation solutions that go through the control of water to make irrigated agriculture throughout the year” (Assane Dione)
Thirty-five years ago, an agricultural engineer, Jacques DUBOIS, a specialist in soil pedology and hydrogeology, who had spent his whole career in agricultural hydraulics in Senegal, was retiring. Having become widowed, with a perfect knowledge of the land and man, a golden heart, a solid character and unwavering perseverance, he had an idea of genius concerning the development of a rural area at South of Bakel, in the Sahel, not far from the triple point of Senegal, Mauritania and Mali.
The climate of this zone translates into two months of intense rainy season in August and September, when the wadis (wadis) have violent and devastating floods, followed by ten months of absolute drought. During this drought the villages lack water, and the water tables are exhausted, forcing to seek deeper and deeper the water that is lacking in gardens, cattle, and domestic usages. This shortage of water was a powerful factor in rural emigration.
The idea of our agronomist was simple: to create in the bed of the backwaters small reservoirs of low height, storing the water in period of flood to make it available during the following drought. Each reservoir had to be constructed of local materials, while being very simple and very economical to carry out by the inhabitants of the neighboring village. They were held responsible for the maintenance and repair of breaches occurring during exceptional floods, so that each reservoir could be considered by each village as its own property. The decision to build, and the modalities of construction, was made only by unanimous agreement of the villagers, accepting the time necessary for the palaver, their slowness, and sometimes some errors, the aim being to propose solutions without ever imposing them.
The first idea, and the first realization, near the village of Gouniang, was to create a reservoir immediately downstream of an alluvial plain, itself gridded by a network of bunds of low height along the level lines, for To systematically search for the flooding of these plains at each flood, and to retain the water as long as possible, so as to favor the development of the surface vegetation while replenishing the local water table. Forcing the water to spread over an alluvial plain was also a means of reducing the down-flow of the downstream marigot and thus the destructive force of the flood. And since 1981, rice could be grown.
This achievement, achieved by the agronomist at the wrist, despite the obstacles of every kind imagined, was a success. Little by little, by word of mouth helped, he was more and more solicited. Since the ideal profile of alluvial plain to be flooded was not frequent, it confined itself to building over thirty years, at least allowing the nearest village to have water during the dry season for food Livestock, irrigation, fisheries and domestic needs.
It is time to give some details on the practical implementation of these achievements. First of all, our agronomist created in France a legal structure with an office in Bakel: a small NGO, the GRED (Eco-Development Research and Development Group). It required an expert to make the projects of the structures, adapted to the local conditions and the local materials. He was a retired volunteer engineer, Jean ABERLEN (Centrale 1938) with considerable experience in hydraulic engineering, who finished his career as a professor in the largest public works schools, and who conceived in Cote d’Ivoire the ” Geo-concrete “, a mixture of earth and cement, used either to make the sealing core of an earthen dam, or to constitute the dike itself. Of course, armourstones are also used, when they are available on site.
The height of the dikes is deliberately limited, in order to avoid disaster in the event of breakage of the dike: most are between 3 and 7 meters high; A single rise to 9 meters. Great care is taken in the spillway. The capacity of the reservoir for feeding in the dry period varies according to the land: out of 30 reservoirs, 10 ensure a permanent presence of water throughout the dry season; The others a presence of water varying from two to seven months.
Funds were needed, because even in the economy, it was not easy to work more than 600 kilometers from Dakar, to rent a minimum of gear, and to cover the cost of the local structure, including the one A local permanent GRED team led by Assane DIONE, a highly motivated young Senegalese engineer trained by our agronomist and financially supported by the latter for studies in agronomy in France, to take his follow-up. These funds came from various sources: the contribution of the villagers, mainly from the funds sent by their emigrant workers, contributions from members of the GRED, some subsidies (general councils of Ile de France and Isère), and Which concerns new works, the financing provided by the Franco-Senegalese CODEV.
A difficulty of execution is the relatively small time slot left by nature to the workers: the land must be dry enough, but not too much to be able to be worked: this leaves little more than a useful quarter of December To February.
The main problem of GRED was to finance the cost of repairs to the works. The current climate change is reflected in the region by torrential rains of a level never observed by the ancients, and thus high floods that damage one to three dams each year, causing regressive breaches or erosions that are sometimes easily repairable, Sometimes deeper. However, its partners generally take charge of new constructions, not their maintenance, which can only be carried out during the winter months, as said above. It is therefore necessary to find other resources
A major project, the dam of Goundiourou, of which the major flood of 2009 opened a breach in the dike, was able to see the financing of its repair assured by the donation of 3,000 € sent by the NGO AIMVER. It can then return to active service: its water supply ensures the perennial water needs of the dry season (vegetable crops, watering of animals, domestic work …).
A detail: informed of the breach of Goundiourou, Jacques DUBOIS, initiator of the project immediately went to the site despite his 89 years old, to inspect the work, to note the damage and to establish the method of repair and consolidation. As for Jean ABERLEN, then 95 years old, he could only give advice from a distance. He died a few months later.
At the end of 2011 Jacques DUBOIS was in his turn suffering from the first symptoms of Alzheimer’s disease which prevailed on May 31, 2014.
Following the GRED was assured by its merger with GRDR (Group for Research and Projects for Rural Development) on 1 st January 2012.
The greatest satisfaction of Jacques DUBOIS was to hear a peasant say to him:
“No need to go to France to earn money! “