Climate change is by far the most crucial problem of our time. As a part of the world, it is impossible for us to not be part of this global phenomenon, albeit the fact that Nepal’s contribution to the global climate change is negligible (less than 0.027%). Impacts of climate change have started to become evident, be it through the changing climatic patterns or decreasing agricultural productivity or the declining status of natural resources. It is the time we start taking the adaptation measures seriously and invest in them.
Despite bestowed with an abundance of water resources (enough to generate 83,000 megawatts of hydroelectricity), rainfalls, and precipitation, Nepal seems to be a country in dire need of clean drinking water and irrigation for its people. Analyses of monthly flow trend of some of the rivers indicate that the contribution of snowmelt in runoff is an increasing trend for snow-fed rivers, while for non-snow-fed rivers, dry season flows are decreasing and wet season flows are increasing. Conventional resources of portable water is depleting in the mountainous region of Nepal year after year due to receding glaciers and other environmental changes that are beyond Nepal’s own control along with the human-induced causes. This calls for the proper adaptation strategy in the water resource sector if the future availability is to be ensured.
It is no secret that, the health of the people depends on the food they feed on, the climate they thrive on and the water they drink. However, the 80% of the population has access to drinking water, is not safe. No wonder 44000 children die every year in Nepal due to water-borne diseases. Immense fresh water, on an average precipitation of 1400 mm per year, that falls over Nepal runs off without effective use and largely drains as monsoon flood due to the absence of appropriate techniques or technologies for its sustainable use.
Nepal is solely dependent on the rain-fed system for water which is to be used for both the domestic as well as other purposes. In this context, rainwater harvesting which is the technique of accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off comes as a rescue. It helps in collection and utilization of the rain that falls on rooftops and other surfaces for immediate and future use.
Rainwater harvesting is the accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off. It is the collection and utilization of the rain that falls on rooftops and other surfaces either by using storage tanks or recharging the rainwater into underground sources such as tube wells. Rainwater is harvested mainly in two ways as Surface runoff harvesting and Roof Top rainwater harvesting
Rainwater harvesting in Nepal
Many households in Nepal’s mid-hills suffer from water shortages during the pronounced dry season. Some parts of Nepal have been following the roof-top rainwater harvesting. The harvesting system consists of a catchment roof, conveyance pipes, and a storage jar. The pipes include a gutter system made from longitudinally split polythene pipe which has a flushing system that allows the system to be periodically flushed clean. Because of this, the people can save thousands of rupees a year as opposed to buying the popular, yet questionable quality, water available in jars in the market from 40 to 150 rupees per 20 liters. This saves between 6000-10,000 rupees a year.
Rainwater Harvesting Capacity Centre (RHCC) established in 2006 has been promoting the technology of Rainwater Harvesting in Nepal. It provides long-term access to safe water for vulnerable communities primarily in ‘Type 3 areas’, where people have no access to surface water, has no alternative sources such as borehole or spring potential, and/or suffer from restrictions due to poor water quality. SmartPaani has been working in this field in Nepal with hundreds of installations in Kathmandu Valley since 2007 with its custom-designed SmartPaani’s Rapid Sand Filter.
The harvested water has a huge potential to solve the current problem of water shortage and depletion arising from continuous climate change. Not only for drinking and household purposes, this can be a solution to the irrigation water required in the field, recharging the groundwater, fulfilling the basic water requirement of crops and livestock and many other purposes. In this peak time, when the impacts of climate change are most felt, rainwater harvesting ideas comes as a boon. This practice could at least cross off one of the problems amongst others arising due to climate change.
B.Sc.Ag, final year
Agriculture and Forestry University, Chitwan, Nepal