Author(s)

Lazare Kouakou Kouassi, Innocent Kouassi Kouamé, Séraphin Kouakou Konan, Brou Dibi, Soumahoro Moussa, Diakaria Koné, Dago Gnakri

Laboratoire des Sciences de l’eau et de l’Environnement, Université Jean Lorougnon Guédé, Daloa, C?te d’Ivoire.
Laboratoire Géosciences et Environnement, Université Nangui Abrogoua, Abidjan, C?te d’Ivoire.
Office National de l’Eau Potable (ONEP), Direction des Ressources en Eau, Abidjan, C?te d’Ivoire.
Projet d’Aménagement Hydroagricole de la Vallée du N’Zi, ONDR_MINAGRI, Dimbokro, C?te d’Ivoire.

This study aims at characterizing the physical environment and suggesting solutions for a better management of the hydro-agricultural dam of M’Bahiakro which is being constructed over the N’Zi River and is the first inflatable dam in Cote d’Ivoire. In this survey, data related to hydrology, characteristics of the dam and the irrigated rice production area were obtained with the Water Resources Agency and the National Office of Rice Development of Cote d’Ivoire. Physicochemical parameters of the N’Zi River were collected seasonally at three monitoring stations. Results showed that the N’Zi River is characterized by a high water level period from April to November and a low water level period from November to April. The gap between the low flows and the high flows is important (about 206 m³/s on average). The annual average flow is 40 m³/s with a standard deviation of 32.52 m³/s and a variation coefficient of 0.88. The SAR average value (1.63) and the average conductivity (78.44 μS/cm) showed that waters of the N’Zi River are of high quality to be used for irrigation. Suspended sediment concentrations do not present significant difference along the river. But the seasonal variations are important; they are higher during the rainy seasons (45.8 mg/L on average) than in the dry seasons (17.7 mg/L on average). The annual solid flux of the N’Zi River is 41897 tons, i.e. 15810 m³ of sediments. The annual sediment flux is important and can lead to high depositions in the line-shaped reservoir of the dam and that calls for attention to control the silting up of the reservoir. Great efforts concerning interdisciplinary approaches, as well as extensive and intensive field work are needed in order to better manage the hydro-agricultural dam of M’Bahiakro.

Hydrology; Irrigation; Dam; Suspended Sediment; N’Zi River

Kouassi, L. , Kouamé, I. , Konan, S. , Dibi, B. , Moussa, S. , Koné, D. and Gnakri, D. (2013) Prospects for Minimizing the Potential Environmental Impacts of the Hydro-Agricultural Dam of M’Bahiakro (Côte d’Ivoire). Journal of Water Resource and Protection, 5, 847-853. doi: 10.4236/jwarp.2013.59085.