Future Urban Water Crisis in Mountain Regions: Example of Kathmandu Valley, Nepal

Abstract

The civilization of Kathmandu Valley has started alongside the holy Bagmati River. However, rapid urban expansion and overpopulation have resulted not only inwater shortage but ended up polluting the samewater body based on which the settlements had grown, a classic example can be taken as that of Kathmandu and other surrounding cities in Kathmandu Valley. Due to resource availability and cen- tralized government system, many people have migrated to the Kathmandu in recent decades. The annual population growth rate in the valley is 4.63% (CBS 2011) which has created haphazard urbanization resulting in water supply challenges. Geologi- cally, Kathmandu Valley is an intermountain bowl-shaped basin comprised of both shallow and deep aquifers composed of fluvio-lacustrine sediments. Sandy gravel layers of northern side of the valley are considered the recharge zone due to the presence of unconsolidated coarse-grained deposits. Unfortunately, the area has the fastest urban growth and surface sealing, resulting in decrease in natural infiltra- tion. Kathmandu Upatyaka Khanepani Limited (KUKL), the only one organization facilitated by the government, provides approximately 25–33% of the total demand of 350 MLD. Analyses have shown that there will not be water shortage between 2023 and 2025 if the Melamchi Water supply Project (MWSP) is completed within the allocated time. However, even that would not quench the thirst of the people as the demand is expected to rise in coming years. Proper planning, good governance identification of water sources, and water treatment of wastewater are the long-term solutions for sufficient water supply. Alternate mitigation options, such as proper use of groundwater and surface water and spring water management with appropriate distribution system, would be useful. Unless the problem is tackled tactfully from different aspects and not only from demand supply and soon, the increasing social conflicts could be challenging for the planners in the future.