- Neglect and levelling of ponds have directly contributed to the drying up of fresh water springs in Nepal’s Mid Hills
Nov 4, 2014-
Rainfall is the ultimate source of the water we use—more than 80 percent of the total annual rainfall occurs in the four monsoon months while the rest of the year is more or less dry, except for brief winter and pre-monsoon showers. Much of the monsoon rain runs off downhill; however, a fraction infiltrates into the earth, is stored as groundwater and feeds the springs. The water that gets stored underground should be thought of as a ‘water tower’ within the hillocks, which rises and falls depending on the amount of water recharged by the rain and the amount flowing out of the springs.
Lately, migration of desperate people suffering from a chronic lack of water in their villages has accelerated from the hills and mountains. The springs that once used to flow profusely have now started to dry up, raising serious concerns about the sustainability of the sources of water in these regions. Challenged by this phenomenon, the Nepal Water Conservation Foundation (NWCF), in collaboration with the International Center for Integrated Mountain Development (Icimod), decided to investigate the science, both natural and social, of water storage in the hills and the functioning of the springs. Two small pilot study sites in Kavrepalanchok district were selected to conduct preliminary research in this area, one in and around Tinpiple of Panchkhal VDC and the other in Darauneokhari VDC in Dapcha area, an old trade route from Kathmandu to the eastern parts of Nepal.
Our investigation showed some major surprises: Nepal’s Mid Hills are rich in springs but they are dying. There are approximately five to seven springs per square kilometre but as much as thirty percent had dried up completely over the past 15 years. What are the reasons for this alarming state of affairs?
One knee-jerk response to this question was the ubiquitous ‘climate change’. While data shows that there has been some slight variability in monsoon rainfall over the years, our investigation showed that this was not sufficient to account for the scale of the problem and that there were other overriding factors that exacerbate this problem. One was the rampant use of bulldozers to open new tracks in the hills without giving thought to the environment or traditional water systems. A consequence of this has been the disruption of subsurface hydrology and the feeding of the springs. Another is the construction of deep borings and drawing water with high capacity pumps in the valleys below, which suck water away from the water tower, thus desiccating the springs upstream.
As bad as these drivers were, another important reason was that villagers had neglected to recharge their water tower. Traditionally, there used to be a proliferation of ponds in or near settlements in the Mid Hills, mostly used for the wallowing of buffaloes, watering animals, and sometimes for minor irrigation. Unknowingly, these ponds had played a vital role in recharging underground water by allowing water to seep into the ground below. Their invisible role in recharging the water tower was not appreciated, mainly because a couple of decades back, there was no acute shortage of water in the springs and the malaria eradication programme thought that they were a hazard. Meanwhile, with the decline in livestock population, ponds were not in demand anymore and they were neglected, with the consequence that most of them have now become levelled to make way for schools, volleyball grounds, VDC buildings, and even private houses.
While looking for possible ways to revive the dried up springs, this simple way of recharging the water tower emerged as the most promising technology. We rehabilitated three old ponds in each site with the active participation of respective communities. After a few interactions with the local people, they started to appreciate this unique relationship between ponds and springs and became willing to test this hypothesis with us. As a result, there was a highly encouraging turnout of locals for voluntary labour contribution to rehabilitate those ponds.
These ponds were rehabilitated just before the onset of the monsoon of 2014 and were able to capture considerable volume of the runoff water during the monsoon. The initial results have been very encouraging. First of all, the ponds were filled with water during the rainy season. It seems reasonable to assume that a significant proportion of the captured water found its way into the underground reservoir and contributed to the rise in water level of the water tower and ultimately helped feed the springs downstream. A spring that had been completely dry for at least five years in the influence zone of one of the rehabilitated ponds called Thanti Pokhari yielded water last September. This encouraged the local people so much that some have already started to build recharge ponds on their own land in the hope of reviving other springs or increasing flows in existing ones.
This example demonstrates what can be done with very little external resources to solve problems at the local level using simple, traditional technology and local initiatives. However, one pond in one locality is not enough. A larger national campaign is needed to rehabilitate and construct many small recharge ponds, peppering the hills and mountains of Nepal with them. If we can capture and retain uphill even a small percentage of the monsoon and winter rains, that would rejuvenate springs and hill livelihoods as well. Failure to do so might not only mean that hill springs will dry up or the monsoon rains not retained uphill will wash off downhill as flood flows causing landslides, but also lead to the depopulation of Nepal’s Mid Hills and hill livelihood as we know it.
Sharma is a senior researcher at Nepal Water Conservation Foundation, currently working on a pilot study of springs and recharge ponds in the Mid Hills.This article is based on the preliminary findings of that study
Published: 05-11-2014 09:04