A colleague and I (left) visiting a local spring.
One thing about the fellowship that I like is the monthly writing of blogs, even though many people have praised me for my writing, a few have also been critical. One of the biggest criticisms that I have got is the fact that I rarely write about my work, and it is true, I have not written anything substantial about the work I do in the field. So this blog is about a problem that I observed in my field. I work with Chirag in Kumaon region of Uttarakhand on a project on Spring Recharge.
What are Himalayan springs and why should we preserve (recharge) them?
Springs are groundwater discharge points that appear where a water bearing layer (aquifer) intersects with the ground surface and water seeps out of rock pores, fissures, fractures, or depressions. Springs are the main source of water for millions of people in the mid hills of the Himalayas. The main source for the water in the springs are the rainwater that percolates into the underground aquifers. Both rural and urban communities depend on springs to meet their drinking, domestic, and agricultural water needs. In addition, springs play an important role in providing water for ecosystem services, such as base flow in rivers, while supporting vegetation and wildlife Springs in the Himalayas also have religious and cultural significance.
Over the years, there has been an increasing concern that springs are drying up, becoming seasonal, or their discharge reducing. A study by P.C. Tiwari (2000) found that around 45% of springs in one catchment in the Central Indian Himalayas had dried up or become seasonal, while a survey of villages in another catchment in the same region found a decline in spring discharge by 25–75% over the previous 50 years (Valdiya and Bartarya, 1991). Over 37,50,000 people, including 18,00,000+ women, of the Kumaon Himalaya rely primarily on springs for all water needs (2,60,000 springs provide 90% of Uttarakhand’s domestic water). The 2018 NITI Aayog Report details the precipitous decline in Himalayan spring water availability and quality.
Anthropocene factors (land use change, urbanization/tourism, fuel wood/fodder demands, spring shed bacterial/chemical contamination) and environmental factors (climate change, increased variability in seasonal and geographic precipitation and temperatures) contribute to springs decline.NITI Aayog Report
The precipitation data of the last century from Indian Meteorological Department shows that districts like Almora, Bageshwar, Champawat, Nainital and Pithoragarh in Uttarakhand show a decline in rainfall by 12%-17%, further increasing the already water stressed area. More than half of perennial springs have dried. Over last 150 years, functioning springs in Almora district alone, have decreased six-fold from 360 to 60.
We, at Chirag, recharge the Himalayan springs by undertaking a hydro-geological survey and generating a slope map for the purpose of making the water peculate into the ground by digging contour trenches, percolation pits, khals as well as undertaking plantation activities in areas where the slope is high (above 50%).
An invasive species that threatens the water security
Apart from the declining rainfall and change in land use, another threat to the Himalayan spring is an aggressively spreading invasive weed locally called Kala Bhasa (Ageratina Adenophora, commonly known as Mexican devil, crofton weed or sticky eupatorium). It can be seen in all terrains, on roadsides, edges of agricultural fields, near human habitations, open areas, and in disturbed forest patches. But its most alarming growth (where it grows to as much as 9-10 feet tall against an average of 3-6 feet) is in and around streams and rivers (riparian zones), where its roots form a virtual net over the stream’s gravelly bed and prevent water from flowing further. The water, thus trapped is unable to make its way to lakes and rivers, resulting in a drastic reduction in the water levels across Uttarakhand.
Every year (in March‐April), a single mature plant can produce 10,000 to 1,00,000 seeds, which disperse by wind and water. These seeds can also travel long distances by sticking to animals, humans,vehicles and agricultural machinery. The spread of the weed currently shows no sign of slowing down, as per a study by Lamsal et all 2018, the kala bhasa’s range and spread in the Himalayan region is further going to increase owning to its resilience to climate change as compared to other local flora.
Kala bhasa changes the bacterial and fungal composition of the soil in a manner that enables its own growth and hampers the growth of local plants, thus forming dense mono cultures and reducing the native biodiversity. Such invasion of alien species is recognized by the International Union for Conservation of Nature(IUCN) as the second greatest agent of species endangerment and extinction, after habitat destruction. Even broken branches can take root and increase plant density, making the occasional plant also capable of severe infestation. Cattle find it unpalatable; sheep and goats are indifferent to it. Its spread is virtually unhindered.
What can be done?
The immediate need is to prevent dispersal of seeds in November-December this year or March‐April, next year. Slashing only promotes more vigorous growth, hence mechanical control by uprooting and burning the entire plant (with roots) seems the most viable method. While the elimination of kala bhasa is virtually impossible, control is achievable through continuous and diligent effort, year on year, particularly since the most vigorous growth are in areas like streams and drains.
Once an area has been cleared of kala bhasa and maintained clean by the regular uprooting of the occasional plant, moist conditions allow local grasses and other plants to establish and cover the disturbed area. Alternately, replacement planting may be useful, using local grasses like dooba and clover. Such biological replacement control proved successful in severely infested parts of southwest China in 1980s. Because a significant seed bank may already exist in the soil, consistent follow‐up work is required for sustainable management, in the form of uprooting any plants seen in a once‐cleared patch, and encouraging the revival of local species. In South Africa, the Working for Water Program provides employment for clearing invasive plants, an option that can be considered using a structured or institutional approach.
A successful example of revival of local spring in Uttarakhand is the case of Deepak Purohit who led a small group of children from villages who have been clearing their water sources from Kala Bhasa in village Baret, near Nathuakhan in 2016. They have seen a remarkable improvement in the water flowing in their streams, as well as a resurgence of local plants like Dooba, Clover, Tushar and Ferns in the vicinity. They also claim that there has been an increase in the amount of water flow in their local Nala post the clearing of Kala Bhasa.
We measure the flow of water in the springs through LPM or liters per minute, which essentially means how many liters of water flows out of the spring in a minute. However, the impact of their exercise has not been measured quantitatively in terms of the increase in LPM. Even though there are many papers that tell about impact of Kala Bhasa on ground water, there has been no research on the impact of Kala Bhasa on a spring’s discharge. If we are able to monitor the discharge of water from a spring before and after clearing the weed, it could led to a new structured approach to the fight of keeping our springs alive.