The term “water quality” describes the physical, chemical and microbiological characteristics of water. These properties which are either inherent in the water or are result of substances that are dissolved or suspended in the water, together determine the general water quality and the suitability of the water for a particular use.The water quality data of Kubanni reservoir, Zaria-Nigeria for 7 years (January 2014 to December 2020) was collected and analyzed to determine the Water Quality Index. Six water quality parameters were analyzed due to their significance in influencing the water quality variation of the reservoir. They are; Turbidity, Electrical Conductivity (EC), Temperature, Total Dissolved Solids (TDS), Free Carbon dioxide and Manganese (Mn). The Water Quality Index (WQI) was determined using Canadian Council of Ministers of the Environment Water Quality Index (CCMEWQI).Results showed that the WQI is higher in the rainy season (38.30) than in the dry season (37.21). However, WQI suggest that the Water Quality of the reservoir is mostly poor during the dry and rainy season based on the Canadian Council of Ministers and Environment Water Quality Index rating.Water Quality Index value ranging from 0 to 44 is considered poor. The poor water quality of the reservoir could be attributed to anthropogenic activities and agricultural runoff around the reservoir. It was further recommended for water quality regulatory bodies to monitor the anthropogenic activities and the inflow of agricultural runoff into the reservoir.
