The estuarine part of the Ebrié Lagoon is under enormous anthropogenic pressures and seasonal natural forcings. A monitoring of the evolution of its hydrology during the year 2014 revealed that it is strongly influenced by the lagoon seasons. Thus, salinity, pH, dis-sub oxygen, temperature and transparency are higher in low water season especially in the vicinity of the Vridi channel under strong marine influence (Biétri and Azito channel). Suspended solids are more abundant during the rainy season, especially in the center of the estuarine zone where domestic and industrial discharges are more increased (Biétri, Cocody and Marcory). Nutrient salts (ammonium, phosphates, nitrates, nitrites) characterize the flood season, especially in the eastern part of the estuary, near the Comoé River (Koumassi and M'badon). The waters of the estuary are warm, poor in oxygen, nitrites and nitrates but rich in phosphates and ammonium.