www.ccsenet.org/enrr Environment and Natural Resources Research Vol. 1, No. 1; December 2011 Published by Canadian Center of Science and Education 63 Water Quality and Environmental Impact Assessment of a Tropical Waterfall System Benedict O Offem (Corresponding author) Department of Fisheries, Faculty of Agriculture and Forestry Obubra campus, Cross River University of Technology, Nigeria Tel: 08-055-930-219 E-mail: benbeff06@yahoo.com Gabriel U Ikpi Department of Fisheries, Faculty of Agriculture and Forestry Obubra campus, Cross River University of Technology, Nigeria E-mail: gikpi@yahoo.com Received: September 25, 2011 Accepted: November 10, 2011 Published: December 1, 2011 doi:10.5539/enrr.v1n1p63 URL: http://dx.doi.org/10.5539/enrr.v1n1p63 Abstract To provide information on the water quality and productivity of waterfalls, monthly samples were taken from three sites along the 6817.7m long Agbokum waterfalls for 24 months (January 2007-January 2009) during wet and dry seasons. Apart from pH, Cadmium (Cd), Chromium (Cr) Ammonium (NH4+), Lead (Pb), alkalinity, Surface Temperature, Air temperature, water velocity and rainfall, all other environmental parameters showed significant variation between sampling sites. Most parameters including water discharge (1496.5 ± 82.9), dissolved oxygen (9.6 ± 0.2), conductivity (69.0 ± 18.5), calcium (16.9 ± 1.2), magnesium (2.5 ± 0.04), silicon (2.5 ± 0.04), Iron (0.08 ± 0.02), Manganese (0.8 ± 0.2), Total solids (178.6 ± 8.8) and Total hardness (74.5 ± 4.3) were highest in waterfalls region (midstream) of the river. Deleterious levels of Fe, Pb, Cd and Mn, above recommended levels, in the waterfalls region of the river and in the wet samples coupled with the acidic nature of the wet samples poses potential health hazards to the aquatic organisms and the inhabitants of the area that use this water resource directly for domestic purpose without treatment. The results indicate a deteriorating water quality of Agbokum waterfalls with the waterfalls region and wet season being most critical in the effective management of the water body. Keywords: Waterfalls, Hydrological parameters, Physic-chemical properties, Heavy metals, Wet season, Dry season, Seasonal variation, Spatial variation 1. Introduction Water resource is one of the major components of environmental resources threatened by exploitation and pollution due to human activity (Efe, 2002a). In the developing countries, good quality water is scarce because of environmental pollution and degradation (Efe, 2002b). Regular monitoring of water resources in the area is therefore important for proper management strategies. Waterfalls, most of which are formed from stream or river which cascade from a high elevation over a cliff or rock, had very little attention from researchers the world over. In Africa, the reason being that, waterfalls were named after deities and were used as places of traditional and ancestral worships. In other places, the intensity of waterfalls and pressure generated from it due to gravity has given the impression of a lifeless zone (Chernicoff et al., 1997). Knowledge of waterfalls systems in Africa are therefore limited to hydrology and geological features (Fischer and Harris, 2003; Chester et al., 1999) and as natural monuments for revenue generation because of their ecotourism potentials (Ayodele, 1988; Krinitskii, 1972). Physico-chemical characteristics are very vital water quality monitoring parameters due to their instability once water is extracted from its source. Knowledge of physico-chemical parameters provides information on the productivity of water resource, type of water treatment process to be adopted and permit better understanding of the ability of populations of organisms to survive in them (Boyd & Lichtkopeller, 1985; Ayodele & Ajani, 1999;