The suitability of water in river Mpanga for irrigation and domestic purposes in Mt. Rwenzori foothills - A short communication

Abstract

River Mpanga supports livelihoods of an estimated 1.2 million people in Uganda. The people depend on it for domestic, irrigation and industrial purposes. This study assessed the suitability of water in River Mpanga for irrigation and domestic purposes. Laboratory analyses were made for the chemical parameters (pH, N, P, K, Na, Mg and Ca). Water quality was determined using the Weighted Arithmetic Index Method for assessing Water Quality Index (WQI). The quality of irrigation water was assessed using water quality indices that included Sodium Adsorption Ratio (SAR), sodium percentage (Na %), Magnesium Hazard (MH) and Kelly’s index (KI). The chemical parameters of water in River Mpanga i.e., pH, N, K, Na, Mg and Ca, were below the permissible limits suggested by WHO (World Health Organization) and EPA (Environmental Protection Agency), except for Phosphorous (0.24mg/l) which was above the permissible limits in all sections of the river. However, based on the WQI, which is a collective index, the water of river Mpanga (reading of 466.8 ± 287.81) is not suitable for domestic use as its above >100 recommended by WHO. The SAR, Na%, MH, and KI values were all within the permissible limits with the exception of KI at uppperstream points. Thus, the water in River Mpanga is mostly suitable for irrigation. Efforts should be initiated to stop/prevent soil runoff and other contamination into the river especially in upstream areas.