Environment

Threats to the Kulsi river in Assam

Print edition : February 25, 2022

A Ganges river dolphin (Platanista gangetica gangetica) in the Kulsi river (40 km way from Guwahati), the unique habitat of the species in Kamrup district, Assam. Photo: Ritu Raj Konwar

A veterinary official with a female dolphin that was found dead on the bank of the Kulsi on March 2, 2009. Photo: Ritu Raj Konwar

Manual sand mining on the Kulsi river using country boats, in 2018. Most households of villages close to the river are dependent on fishing and manual sand mining at notified sand quarries of the river for their livelihood. Photo: Ritu Raj Konwar

The sand being offloaded from boats and taken to trucks waiting on the banks of the Kulsi. The price of one cubic metre of Kulsi sand increased from Rs.600 to Rs.700 about five years ago to Rs.1,600 to Rs.1,800 a cubic metre recently. Photo: Ritu Raj Konwar

A rare sighting of a dolphin mother and calf in the Kulsi on June 9, 2018. Abdul Wakid, an internationally recognised river dolphin expert, said that 25 dolphins were counted in the Kulsi in 2021 as were three deaths, which was the highest number of deaths recorded in the past 17 years in the river. Photo: Ritu Raj Konwar

Veterinary officials examining the dead dolphin, which was 7.5 feet (2.3 m) long and weighed around 80 kg. The Assam government declared the river dolphin the “State Aquatic Animal” in 2008 and the Central government notified it as the “National Aquatic Animal” in 2009. The freshwater aquatic mammal, which indicates the health of an aquatic system the same way the tiger indicates the health of a forest, is protected as a Schedule-I species under the Wildlife (Protection) Act, 1972. Photo: Ritu Raj Konwar

Veterinary officials examining the dead dolphin, which was 7.5 feet (2.3 m) long and weighed around 80 kg. The Assam government declared the river dolphin the “State Aquatic Animal” in 2008 and the Central government notified it as the “National Aquatic Animal” in 2009. The freshwater aquatic mammal, which indicates the health of an aquatic system the same way the tiger indicates the health of a forest, is protected as a Schedule-I species under the Wildlife (Protection) Act, 1972. Photo: Ritu Raj Konwar

A dried up and exposed section of the bed of the Kulsi river on January 27. Photo: Ritu Raj Konwar

The large square bases of the pillars of a railway bridge that is under construction on the Kulsi. The inadequate spacing between pillars does not allow for the free flow of water. Photo: Ritu Raj Konwar

Fishermen pay annual licence fees to the Revenue Department so that they can carry out fishing activities on the river stretch from the Batha confluence up to Gumi and the four major wetlands along this stretch. With the Kulsi river flow falling, the productivity of the wetlands in riparian areas has drastically declined. Photo: Ritu Raj Konwar

Mechanised sand extraction from the Kulsi. There is a high demand for Kulsi river sand as it is not mixed with silt or tiny stone particles and does not require sieving, which saves time and labour costs in construction work. The mosquito nets used to trap the sand mixed with water sucked out from the river with pumps do the sieving. Photo: Ritu Raj Konwar

A bamboo structure used to store sand extracted mechanically using suction pumps located just below a watch tower of the Forest Department near the Kulsi-Chaygaon confluence bears testimony to the illegal unsustainable sand mining taking place in the area, photographed on January 27. Photo: Ritu Raj Konwar

Effluent coming out through holes in the boundary wall of an industrial unit and entering the waters of the Batha near the confluence of the Kulsi and the Batha. Photo: Ritu Raj Konwar

Map

The Kulsi river in Assam is a habitat of the endangered Ganges river dolphin, but illegal sand mining and the existence and construction of bridges are altering the water-flow regime, posing a serious threat to the aquatic mammal and to the riparian communities that depend on the Kulsi for their livelihoods.

Indiscriminate and illegal mechanised sand mining, unplanned industrial growth and construction activities have destroyed the Kulsi river, the unique habitat of the endangered Ganges river dolphin (Platanista gangetica gangetica) in Kamrup district, Assam; the water depth has fallen below one metre in 35 locations and in 9 of these the river is virtually dry. Experts have warned that the residential population of the national aquatic animal is on the verge of extinction in the Kulsi. Besides, destruction of the river ecology and its riparian areas has turned thousands of fishermen living in nearby villages into daily-wage earners. The Assam government declared the river dolphin the “State Aquatic Animal” in 2008 and the Central government notified it as the “National Aquatic Animal” in 2009. The freshwater aquatic mammal, which indicates the health of an aquatic system the same way the tiger indicates the health of a forest, is protected as a Schedule-I species under the Wildlife (Protection) Act, 1972.

Images of the vibrant flow of the Kulsi, a southern tributary of the Brahmaputra that rolls down from Meghalaya hills, have been replaced with those showing vast dry stretches of hard riverbed lying exposed with the sand layer completely gone. A report brought out by the Wildlife Institute of India (WII), Dehradun, Uttarakhand, titled “Status of Ganges River Dolphins in Kulsi River, Assam 2021” states: “Based on long-term observations in Kulsi and elsewhere, it is now understood that dolphins prefer habitat where depth is greater than 2 m (metres). During our recent survey, where observations were taken every 100 m and averaged over 300 m, we observed 35 locations, each with 300 metre segments of Kulsi River, where average water depth was less than or equal to one metre. Out of these 35 segments, 9 segments had almost no water.”

The WII estimated from satellite data that there was a 70 per cent depth reduction in the river area in 2021 compared with 2020. These conditions have resulted in localised populations of dolphins within the river. “During the survey, three stranded dolphins were recorded in a small pool near Kukurmara, in a pool of 500 m, between two non-navigable very low water regions,” the report says.

The report mentions mechanised sand mining activities as one of the factors responsible for altering the water-flow regime of the Kulsi. This shift in flow regime can be observed when one visits Kulsi village where the river branches into two streams: the Kulsi and the Chaygaon. Long-term extensive mechanised sand mining activities, especially upstream of the river, have resulted in the diversion of more water into the Chaygaon, leaving the Kulsi almost dry for the first 10 kilometres up to Kukurmara, the WII report states.

After travelling 12 km from its origin, the river enters Kamrup district in Assam at Ukiam and takes the name Kulsi and finally flows into the Brahmaputra at Nagarbera. From Kulsi village to Nagarbera, the river is about 76 km long. Apart from the Kulsi-Chaygaon confluence, the river has three other confluences. At the confluence of the Batha and Kulsi upstream of the Kukurmara point, which is about 45 km from Guwahati, industrial construction has adversely impacted the dolphin hotspot and its population has now disappeared from this confluence.

A bamboo structure used to store sand extracted mechanically using suction pumps located just below a watch tower of the Forest Department near the Kulsi-Chaygaon confluence bears testimony to the illegal unsustainable sand mining taking place. Traces of the blue mosquito nets used to trap the sand sucked out indicate the modus operandi of the sand mafia barely a few hundred metres from the Kulsi Range Office of the Forest Department.

Fragmentation of habitat

Abdul Wakid, an internationally recognised river dolphin expert who has been monitoring the dolphins of the Kulsi for the past 17 years as part of his research work on the dolphins of the Brahmaputra river system, said that India accounted for 90 per cent of the global population of the Ganges river dolphin and Assam accounted for 30 per cent of the dolphin population of the country. He said that 25 dolphins were counted in the Kulsi in 2021 as were three deaths, which was the highest number of deaths recorded in the past 17 years in the river. Until 2012, the majority of dolphins used to be sighted in the first 20 km stretch of the river, especially in and around the Kukurmara area, but gradually after that, the dolphin distribution shifted downstream.

Wakid added: “Over a period of 17 years, from 2005 to 2021, altogether a 15-km range reduction of dolphin distribution has been observed in the Kulsi river.”

Wakid said: “River dolphins have no eyesight and use echolocation for navigation, hunting their prey and communicating with each other. ... bridge pillars, both roads and railways, [constructed] without any concern [for the] .. movement of this blind river dolphin species [are an] ... acoustic obstruction to their navigation and foraging activities. Adequate depth and width should be maintained in the existing bridges, and future construction ... must be of suspension bridges... Also sluice gates constructed on the Batha river need to be removed, and the riparian zone of this river needs to be restored as part of restoration of Kulsi river ecology since Batha river is a major water flow source to Kulsi.”

He said that mere restoration of flow of water could not restore the ecology of dolphins in Kulsi river. There has to be a strict ban on harmful anthropogenic activities in the Kulsi for a specific duration so that the river gets the time it requires for restoration of its entire ecosystem.

Three bridges across the river at Kukurmara point—a road bridge along National Highway 37 and two railway bridges—have led to the stranding of dolphins. While the pillars of the road bridge and one railway bridge were round in shape, the multiple pillars of the other railway bridge, which is under construction, have large square bases. The inadequate spacing between pillars of the three bridges does not allow for the free flow of water. The WII flagged the issue in its report, saying that the pillars of bridges already constructed in the Kulsi river occupy a large amount of water surface area and make it difficult for dolphins to move between them. An average river with a width of about 50 m has four to six pillars spanning a total length of 8 m to 12 m, that is, occupying 16 to 25 per cent of the river width. The inter-pillar distance of 5 m or less renders the passage between them too narrow to facilitate any movement of dolphins.

“This adds on the extremely low river depth of less than 1 metre allowing no or minimum movement of dolphins, fragmenting the dolphin populations. This creates multiple sub populations of dolphins which causes a drastic deterioration in the health of the population resulting from altered resource availability and depressed genetic health,” adds the report. The WII has sounded the alarm that prolonged separation of dolphin populations will result in population segregation and local extinctions due to lack of gene flow. There are 14 bridges, including 4 under construction, in the entire stretch of the river.

The drying of the river and the threat to the dolphin population have worried local fishermen dependent on the river and the wetlands it has sustained for generations. Gajiram Das, 65, of No.3 Amtola village, which is close to the river, said: “About five to six years ago when the river was full of water, I had no worries about feeding my family of eight members. I could earn Rs.400–500 a day through fishing, but now I barely get Rs.50–100 a day. Now, I am dependent on daily-wage work and earn Rs.250 to 300 if I get work.” Most households of his village are dependent on fishing and manual sand mining at notified sand quarries of the river for their livelihood. “Sihu [dolphin] is our close friend and helps us in fishing by chasing the fish towards us. If it vanishes, then we will not be able fish in the river as before. Water must flow in Kulsi to save the dolphins,” he added. This writer met him when he had come out in search of manual sand mining work at the stretch below the bridges at the Kukurmara point. Three boats were engaged in manual mining in a small patch of the fragmented stretch. Most of the boats are lying idle at this point of the river where once dolphins in a playful mood used to a be regular sight by the side of boats while local people standing in waist-deep water would be engaged in manual mining using a bucket or a hoe to lift the sand on to their boats.

Fishermen of nearby villages pay annual licence fees to the Revenue Department so that they can carry out fishing activities on the river stretch from the Batha confluence up to Gumi and the four major wetlands along this stretch. With the Kulsi river flow falling, the productivity of the wetlands in riparian areas has drastically declined.

The WII report highlights the fact that the Kulsi river is the primary source of income for the villagers residing nearby, where people are largely involved in fishery practices, sand mining and agriculture for their livelihood. “According to 2011 Census data, the riverscape has 55,972.88 hectares of cultivable land, which is solely dependent for irrigation on natural sources (rainfall and rivers). About 2,500 commercial fishermen are registered under the fisheries of Kulsi river and 1,29,095 cultivators. Due to the presence of fine quality sand in this river, there is high demand, and more than 5,000 families are dependent on this business for their survival,” it states.

Manoj Kumar Das, an environmental activist and a trained dolphin observer associated with the WII and Aaranyak (a non-governmental organisation involved in biodiversity conservation and research activities), said: “In manual sand mining ..., which involves tremendous physical labour, the miners cannot lift sand more than twice in a day and it is sustainable as it is regulated. But in unregulated and illegal mechanised mining, much more sand can be extracted in less than an hour using a suction pump due to which sand layers of the river have vanished in just a couple of years.”

A sand supplier in Guwahati, who did not want to be named, explained that mechanised mining fuelled the demand for Kulsi river sand as it was not mixed with silt or tiny stone particles and did not require sieving, which saved time and labour costs in construction work. The mosquito nets used to trap the sand mixed with water sucked out from the river with pumps do the sieving. The price of one cubic metre of Kulsi sand increased from Rs.600 to Rs.700 about five years ago to Rs.1,600–1,800 a cubic metre recently. The cost in Guwahati of one truck with five cubic metres of Kulsi sand has increased to Rs.9,000 to Rs.10,000, which is an indication of the huge demand for the sand.

From December 2021, supplies of Kulsi sand has been stopped in Guwahati, but for the past couple of years at least 500 trucks of different capacities used to bring sand supplies every night to the Guwahati market, claimed the supplier. Compared with mechanised mining upstream in the Kulsi and in the Chaygaon river, sand manually mined at Kukurmara has less demand as it comes mixed with silt and other particles and requires sieving.

Standing on the hard dry exposed riverbed at Borpit, Manoj Kumar Das told Frontline on January 27: “This spot about 6 km upstream of the river from Kukurmara point where we are standing now had sufficient flowing water above sand layers, and every winter on Republic Day I used to bathe on this stretch of the river with my friends till five years ago.” Over the past 11 years, Manoj Kumar Das, with the guidance of Wakid, has built a network of volunteers and activists all long the Kulsi for the conservation of dolphins. “[Once the] sound of the gushing water of the Kulsi at Ghoramara, about 2 km further upstream of Borpit, could be heard from this Kulsi village,” he lamented, pointing to the dry patches of the river.

The nature lover and social activist Pradip Rabha of Kulsi village said that the drastic fall in the water flow in the Kulsi had adversely affected life along both banks of the river. “Many wells, tube wells have gone dry, while most tube wells require pumping for a long duration to draw water. Betel nuts, coconuts and many other trees have withered,” he said. He said that an embankment that was constructed in 1991 from Kulsi village to the Ghoramara point on the eastern side of the river had protected the nearby villages from four annual waves of flash floods, but the drying of the river because of mechanised sand mining had brought miseries to the people.

Dimpi Bora, Divisional Forest Officer, Kamrup West Division, said that the department had seized many suction pumps used in illegal sand mining from Kulsi and Chaygaon river, but the viable solution to the problem was allowing legal sustainable manual mining as many people were dependent on it for their livelihood. She said that there was a high demand in the Guwahati market for Kulsi sand and halting legal and sustainable sand mining would adversely impact construction activities in the capital city. She claimed that the forest staff did their best to stop illegal activities such as tree felling and mechanised sand mining by seizing suction pumps, excavators and destroying illegal storage structures, but the area under the division was vast, making a round-the-clock vigil a challenging task.

The WII report also flagged the issue of the construction of boundary walls of industries on the Kulsi catchment and alleged that construction activities on the river done “without any thought to aquatic biodiversity have resulted in severe alteration of water flow, and are currently threatening the survival of dolphins in the river”. The report alleges that one of the industrial units has “built its boundary wall on the Kulsi-Batha confluence, and it would have been a violation of Assam Act XIV, had this been in Kamrup Metropolitan District, where construction is banned within 15 m of any waterbody”.

Boundary walls of industries

The report claims that the “boundary wall has destroyed the riparian zones of both the Kulsi and the Jagaliya rivers, blocked the Jagaliya-Sol beel connectivity and thus resulted in reduced flow and limiting of food resources in the Kulsi-Jagalia confluence”. The boundary wall of another industrial unit, the report states, “has been destroying the riparian zone further upstream of the Jagaliya river. In addition, construction of two sluice gates in the upstream of Batha river has resulted in further reduction of already limited flow in the Batha river.”.

During a visit to the spot, effluent coming out through holes in the boundary wall of an industrial unit was observed getting mixed with the waters of the Batha near the confluence of the Kulsi and the Batha. Even though the wall is right on the riverbank, an action plan on the waste management status and proposed actions for municipal solid waste, industrial waste and biomedical waste management on the Kulsi river submitted by the River Rejuvenation Committee, Assam, to the Central Pollution Control Board in 2019 states: “No industrial units have been identified within 500 metres periphery of the catchment area.” The committee had prepared the action plan (uploaded on website of Pollution Control Board, Assam) for the rejuvenation, protection and management of the identified polluted river stretch of Assam in compliance with a National Green Tribunal directive issued in 2018.

On December 28, 2021, after the people of Kulsi convened a public meeting to raise the issue of threat posed by illegal and unsustainable mechanised sand mining to dolphins and to the livelihood of thousands of people, the Kamrup district administration constituted a committee of experts, which visited the Kulsi river on January 8, 2022. Now, Pradip Rabha, Gajiram Das and thousands of residents living on both banks of Kulsi are awaiting action by district authorities to restore the water flow to the river through implementation of remedial measures as suggested by the committee.

They are, however, clueless about the likely impact of the proposed Kulsi multipurpose project that envisages the construction of a dam on the river near the Assam-Meghalaya boundary to generate 55 megawatts of electricity and irrigate 20,500 hectares of land. The project has been declared a national project and its detailed project report is said to be under appraisal by the Central Water Commission and the Brahmaputra Board. “If the multipurpose dam is constructed, the consequences will be catastrophic for the entire Kulsi basin, which may lead to extinction of the Kulsi river dolphin and impact the livelihood of people,” cautioned Wakid.