IWRA World Water Congress 2008 Montpellier France
1. Water availability, use and management
Author(s): K. Gnandi
Dpt. of Geology, Faculty of Sciences, University of
Lomé
Keyword(s): coastal basin of Togo, groundwater resources,
diagnostic analysis, strategic action plan
Poster: PDFAbstractThe sedimentary coastal basin of Togo (Maastrichtien – Continental Terminal) comprises three
principal aquifers which are:
· the confined aquifer of the sands of the Upper Cretaceous, commonly called the
aquifer of the Maastricht,
· the confined aquifer of sand and limestone of the Paleocene,
· and the
unconfined aquifer of the sands and clays of the Continental Terminal.
Furthermore, two some small aquifers are
encountered in this basin namely the aquifer of offshore bars and the aquifer and the clayey sands of the alluvia of the
rivers Mono, Haho and Zio.
The serious problems existing and emerging that represent threats for the
groundwater resources of the coastal basin of Togo are:
1- The lacks and insufficiencies in collecting
hydrological and climatic data of the basin:
2 - The insufficiencies of hydrogeologic knowledge of the aquifers: as
unknown or partially known we have; the geometry of the aquifers and their extension, their hydrodynamic, their
piezometry, the chemistry of groundwater and the interactions between surface and groundwater.
3 – The
exploitation and management of the resources: as serious problems on notes, the overexploitation of the groundwater
in the aquifer of the Continental Terminal (particularly because of it easier accessibility), the saltwater intrusion
enhanced by the over pumping, the lack of the protection zones of the aquifers against various forms of threats of
pollutions.
4 – The insufficiencies in the national capacities of mobilization and distribution of groundwater: the
water supply by the government in the big cities is not sufficient and the districts far away from the city centers are
not served. This has for consequence the multiplication of private wild drillings and the supply of uncontrolled bad
water quality to people. Also the subscription fees are too high for an increasingly poor population.
5 – The
environmental problems among which; the climatic changes, the wild extension of cities, the rapid growing
populations, the transhumance, the decrease in rain fall intensity since decades in the basin, the floods, the
deforestation, the mining activities (phosphorites mining and the dumping of mine tailings into the sea), land
degradation, the growing urban insalubrities (wild cities dumps), the pollution by heavy metals, pesticides, nitrates
and microbes.
The situation is very serious and requires urgent and effective actions to address this alarming
outlook. We suggest the necessity to formulate a Strategic Action Plan (SAP) and to develop a Diagnostic Analysis
(DA) of the aquifers in order to set up legal and institutional frameworks for a better management and protection of
the groundwater resources of the coastal basin of Togo.