Chapter 23 - Water quality status in Bagmati river of Kathmandu valley, Nepal

Abstract

Nepal is rich in water resource with having more than 6000 rivers and rivulets distributed in different river basins. Among the basins, Bagmati River Basin lies in the middle-hill regions of the central Nepal encompassing the capital city Kathmandu. On the bank of the river, there lies a famous and sacred Hindu temples complex the Pashupatinath, one of the world heritage sites. Thus, millions of national and international pilgrims and tourists from across the world visit the place. The Bagmati River is also a preferred place for death ritual for Hindus. Kathmandu Valley that lies within Bagmati River basin has been experiencing the immense pressure of rapid population growth, urbanization, industrialization, land-use change, and increased traffic. From 1990 to 2012, in Kathmandu Valley, built-up area has increased from 38 km2 to 119 km2 with decrease in agricultural land from 421 km2 to 342 km2 causing substantial change in the valley morphology. The practice of direct discharge of industrial effluents and sewage into the river are the major sources of contamination deteriorating the river water quality and making aquatic life and river ecosystem vulnerable. The river is presently characterized by the high organic load and low dissolved oxygen, bacterial contamination, and metal toxicity making the water unsuitable for taking holy bath and other purposes as in the past. Though, various efforts, including Bagmati clean-up campaign for improving water quality has initiated, the visible impact is still awaited. Thus, for restoration of the river, along with effective plan and policies, stringent implementation of strategies, and plans is anticipated.