Biophysical assessment of water quality at mphosong-bolahla catchment

Water quality monitoring is the integrated activity for evaluating the physical, chemical and biological characteristics of water in relation to human health, ecological conditions and designated water uses. However for the purpose of this study, the assessment focused on Temperature, total phosphorus, Total Nitrogen, pH, total dissolved solids, turbidity, Electrical conductivity and base cation (Mg and Ca) concentrations. These being some of the parameter that are measured in water and sewage company in Lesotho to indicate the water quality in our resources, therefore the same thing applied to our study since we were supposed to determine the water quality in Bolahla Mphosong catchment. Water quality and quantity indices were measured from 22 selected water resources. Some water quantity indices were measured right in the field using physical measurements or chemical methods based on a field toolkit while others were measured in the laboratory. The water quality parameters that were measured were, water temperature, pH, EC, TDS, Turbidity, ions (Mg, Ca, , nitrates, phosphates) and chemical oxygen demand while the water quantity parameters included, water flow, water point depth and water flow rate. The water testing kit was used to measure the water quality parameters like temperature, pH, EC and TDS in the selected water resources per sub catchment and other parameter were analyzed in the laboratory. The water testing kit was used to measure water quality while for water quantity, measuring tape, measuring stick and the wading rod were used and the float method and current meter method for flow velocity. Most water resources in terms of water quality seemed to be within the recommended drinking water standards except for the stagnant water in dams and wells however the water quantity (depth, width and flow) seemed to have decreased in the study area.