Springs, not glaciers, fighting back climate change in eastern Himalayas
Armed with science, villagers are pioneering a unique and replicable spring-fed water management system in the eastern Himalayan state of Sikkim. Subhra Priyadarshini reports.
doi:10.1038/nindia.2014.167 Published online 10 December 2014
Basung Doma never went to high school. She would much rather help her father in their farmland. So it comes as a surprise when she rattles off names of all the lithographic formations in and around her small hilltop village in south of Sikkim, a tiny north-east Indian state nestled in the eastern Himalayas.
“This one is a contact spring and that one, on that hill, is a fracture spring“, Doma, now all of 24 and a mother of two, points to a distant blue hill. She amazes further with her precise knowledge, down to millimetres, of how much water each of these rock formations allow to pass within them. Her fellow village folks seem equally at ease with topographic information that’s of use to their agriculture and water use.
Robin Sewa, the Block Development Officer of Namthang, a small town 21 km away from the state’s capital Gangtok, explains the unusually high level of scientific knowledge among the villagers, “They use science in their daily life to tackle the effects of climate change. So it is only in their interest that they master technical knowledge upon which their very survival rests.”
And so ‘water recharge’ and ‘surface run off’ are part of the lingo across villages in Sikkim, a state which is transforming its springs into perennial water sources that don’t dry up in the winters. “It is like recharging your mobile phone, no?” Doma asks playfully.
Glaciers far above, rivers far below
In the Himalayas, glaciers and rivers are hailed as the life source of water. “Springs don’t get much attention but they can turn into the only source of perennial water, if kept recharged”, says Pem Norbu Sherpa, coordinator of Sikkim’s successful Dhara Vikas (or spring development) programme. Sherpa oversees a cadre of young para hydrogeologists trained specifically for the purpose. He spearheads the science-backed watershed management project which has brought to life over 50 small springs and 4 lakes across the winter drought-prone villages of south and west Sikkim since 2008.
“Springs and streams are largely unstudied,” agrees Sandeep Tambe, Commissioner in Sikkim’s rural management and development department. “We always talk about the hydrogeological significance of the mountains in terms of the lowlands. We forget that mountain people in remote villages depend solely on these springs. For them glaciers are far above and rivers far below,” he says explaining the rationale behind the ambitious spring revival programme.
For the mountain folks, ‘climate change’ translates to a marked decline in winter rains. “Even a decade back, these springs would discharge groundwater almost all year round making sure villagers got water for agriculture and household use,” Robin Sewa says. Slowly, as winters saw lesser and lesser rains, the spring waters started to become a trickle1. Population has been on the rise putting pressure on the already scant water resources. “We did not have a choice but to travel long distances to fetch water in the winter months,” says Cheki Sherpa from the Tengaymendang village near Ravangla in South Sikkim, reflecting the general plight of women in the region.
Marrying natural science with social science
Learning from sporadic experiments in the Western Himalayas and blending it with available science and social science, Tambe and his team are making use of funds from India’s flagship national rural employment scheme MGNREGA to revive critical springs, streams and lakes in Sikkim2. The plan is to involve villagers in recharging groundwater on the hilltops, holding surface runoff from monsoon months in trench dug-outs, continuously assessing their climate change related vulnerability and updating a ‘Spring Atlas’ that maps 704 springs across the state.
When it rains in the mountains, just about 15% of the rainwater percolates into the soil to recharge the springs, the rest torrents down the mountains, often causing floods. “This is the water we target – digging up trenches and ponds at geologically sound locations to capture the runoff,” Norbu Sherpa says. The team uses a combination of geographical information system (GIS) and geohydrology to pinpoint the locations where trenches are dug. To revive lakes that have dried up, the team develops their catchments, desilts them and pipes the excess surface flow into them. “Healthy lakes work as recharge stations for groundwater,” Tambe adds.
The springs are slowly bouncing back to life and bringing smiles aplenty. Tambe cites the example of the Sethi Khola stream in Namthang, South Sikkim. People perpetually facing winter droughts from February to April in the nearby villages are now able to grow enough vegetables to export, he says.
The experiments were not without initial setbacks. “We made initial mistakes like digging trenches in terraced lands where surface runoff is low or concreting the ponds not realising that it would hinder groundwater recharge,” Tambe says.
The model that evolved from this trial and error, however, is fool proof and can be replicated across the Himalayan states, Sherpa says. India’s Planning Commission has now included springshed development in a new list of permissible works that states can use MNREGA funds for. “However, one problem that the other states might face is land ownership issues,” he cautions. Unlike many states in the Himalayan span, the Sikkim government owns most of it forest lands and provides incentive to farmers in case their farmland is identified for use in the spring shed programme.
As of now, the Bhabha Atomic Research Centre (BARC) has also begun an environmental fingerprinting study of the Sikkim springs to understand mountain aquifers better and identify recharge areas with greater precision.