First settled by the Aryans around 1200 BC, the flood plains of Ganga have been venerated and worshipped as the symbol of our traditions and values ever since. The entire ecosystem of the Ganga has provided innumerable goods and services to the people of India, hence earning it the sobriquet of being ‘the mother of our civilization’.
Originating at Gomukh on the Gangotri glacier at an altitude of 4,100 m above mean sea level, the river begins its journey as Bhagirathi, traverses a distance of above 2,700 km and confluences at Gangasagar with the sea. The entire stretch of the Ganga can be divided into three major segments: Upper Ganga (Gomukh to Haridwar), Middle Ganga (Haridwar to Varanasi) and Lower Ganga (Varanasi to Gangasagar) based on the geomorphology, stream order, bottom substrates, physico-chemical environmental variables of water and the biodiversity.
The Upper Ganga begins where the Bhagirathi meets the Alaknanda at Devprayag. About 294 km from Gomukh, the river leaves the mountains to enter the alluvial plains at Haridwar at an elevation of about 290 m above mean sea level. After passing through Gangotri, Bhairo Ghati, Harshil, Maneri, Uttarkashi, Tehri, Devprayag, and Rishikesh, the Upper Ganga ends at Haridwar.
The fluvial system of the Upper Ganga is characterised by high velocity, icy cold waters and a three dimensional fluvial ecosystem. It is connected longitudinally; laterally and vertically with different biotopes. The average rainfall in the region of Upper Ganga varies between 1,000 mm to 2,500 mm, of which 50-80 per cent arrives during the June to September monsoon period. The Upper Ganga river basin experiences strong seasonal climatic variations, characterised by the monthly variations in the stream flow. Snow and glacier melt during the hot months (March-June) provides large summer flows in the Upper Ganga.
As per the ecological classification of J Illies and L Botosaneann (1963), the Upper Ganga is the rhithron zone of the river, marked by maximum mean monthly water temperature of 20oC, with high dissolved oxygen and turbulent water currents. The rhithron is again subdivided into three zones—the epi, meta and hypo-rhithron as classified by Ramesh C Sharma, in his book, Rithronology of Bhagirathi, published by Gyanodayain in 1991. The stretch from Gomukh (4,100 m) to Gangnani (1,855 m) can be designated as the epirhithron (no fish zone) with dominant rapids, runs, riffles, waterfalls and cascades. The Gangnani to Devprayag (460 m) stretch termed the ‘snow trout zone’ is characterised by hill fish and is the metarhithron section with few pools. From Devprayag to Haridwar (290 m) is the ‘mahseer zone’ inhabited by sport fish. This is the hyporhithron zone with dominating pools and few runs and rapids.
Surface Water Quality
For a river to function as a water body satisfying its desired use, it must have a certain corresponding degree of water quality. Each water use has a specific quality requirement, with drinking water accorded the highest.
In India, the Central Pollution Control Board (CPCB) has developed a concept of designated best use. Classifying water quality in terms of five designated best uses, that is, drinking water without conventional treatment; outdoor bathing; drinking water after conventional treatment; propagation of wildlife and irrigation; industrial cooling; and, controlled waste disposal—it specifies the pH quality, and parameters for each respectively. Considering that worshippers ritualistically use the waters of Ganga for aachaman (ritual sipping), the quality of the river water assumes utmost importance. The findings of an in-depth study on the environmental variables characterising surface water quality of Upper Ganga for more than four decades are given in Table 1. In the Upper Ganga, heavy metals like cadmium, manganese, lead and mercury were below the detectable limit. However, a considerable concentration of radioactive radon was present.
Surface water quality of the Upper Ganga has been evaluated on the basis of pollution indicators (dissolved oxygen, pH, BOD and density of total coliform). Most physico-chemical parameters including dissolved oxygen, pH and BOD revealed that the water conformed to the A to B categories classified by CPCB and IS 2296: 1992 standards.
However, studies on total coliform density revealed that only the epirhithron zone of the Upper Ganga qualified for A category of water. The upper metarhithronic zone satisfied the B category parameters; whereas the lower stretch of metarhithronic zone did not qualify for B category. The hyporhithronic zone from Rishikesh to Haridwar stretch of the river had to be placed in the C category, due to the presence of high coliform density. This indicates that the river in the epirhithronic stretch (Gomukh and Gangotri) alone is acceptable for drinking purposes. The water in the metarhithronic stretch (Harshil, Uttarkashi) is acceptable for outdoor bathing, while the water in the hyporhithronic stretch does not qualify as acceptable even for outdoor bathing. This could be mainly due to dense settlements along the rivers in this stretch, resulting in open defecation, mixing of organic matter, besides discharge of untreated sewage into the waters of the lower stretch of the Upper Ganga.
Drivers for Degradation of Water Quality
The Upper Ganga is exposed to various natural stresses such as frequent flash flood, cloud bursts, river blockade due to major landslides and earthquakes. Prominent flash floods and ecological disasters encountered by the fluvial system of the upper Ganga included the Alaknanda floods in 1970; massive Bhagirathi floods in August 1978 caused due to river blockade; bursting of Gohna Tal in 1984; the Uttarkashi earthquake of 1991; Assi Ganga and Bhagirathi flash floods in 2012; and the recent flash floods in the Mandakini, Bhagirathi and Alakananda in June 2013. All these natural eco-disasters caused major geomorphic transformations and degradation of the water quality in the Upper Ganga.
In addition to natural drivers there are many anthropogenic pressures such as hydropower projects, construction and widening of roads and highways along the river, excessive extraction of boulders, pebbles and rocks from the riparian zone, unplanned urbanisation and construction of hotels, restaurants, ashrams and even government buildings in the natural flood plains of the river, mixing of untreated sewage, open defecation along river banks, dumping of solid wastes and muck directly into the water.
Besides these, religious activities that include mass bathing, submerging of puja samagri, flowers, jal samadhi by seers and saints and asthi visarjan (immersion of funerary ashes) also contribute to the deterioration of water quality.
Attempts to Clean Ganga
Initial inertia in initiating action to clean the Ganga stemmed largely from the belief that the ‘holy river’, could easily purify itself of pollutants. Although there is some scientific evidence about the Ganga’s high capacity to assimilate a large quantities of organic waste, including pathogens, through bacteriophage, as pointed out by Ernest Hanbury Hankin in 1896 and Felix d’Herell in 1917, no river can sustain its self-purifying power when subjected to present levels of over use, misuse and abuse.
The first tangible Ganga cleaning programme originated from the personal intervention of late Prime Minister Indira Gandhi who had directed the then Central Board for the Prevention and Control of Water Pollution, (presently CPCB) for a comprehensive survey of the Ganga in 1979. CPCB published two reports, which formed the basis of GAP in October 1984. On June 14, 1986, the late Prime Minister, Rajiv Gandhi launched the GAP in Varanasi. However, despite incurring an expenditure of over Rs 2,000 crore, GAP failed to achieve the desired results. There were three major reasons for the failure of GAP I and GAP II. Firstly, there was no ecosystem centric approach; secondly, no integrated effort involving every stakeholder was undertaken—it was a mere engineering centric sectoral project; and, thirdly, there was no public participation.
Recognising the need to improve the river conservation strategy, the Government of India set up the National Ganga River Basin Authority (NGRBA) on February 20, 2009, declaring Ganga as a national river.
Prime Minister Narendra Modi has recently launched the Rs 2037 crore ‘Namami Gange’ project, wherein proposed interventions will involve maintaining the river’s Nirmal Dhara—sewage free waters through sustainable sewage management; Aviral Dhara—undeterred, free flow by enforcing river regulatory zones on banks through restoration and conservation of wetlands, and a riverfront management action plan for Chaar Dhaam yatra and guidelines for river bed sand mining. These interventions are aimed at conserving the upper Ganga ecosystem. However, it is too early to comment on the performance and success of the programme.
The Way Ahead
For any programme aimed at improving the water quality of the Ganga, certain features are essential. It is imperative that a holistic ecosystem centric approach taking care of all the three dimensions of the Ganga—longitudinal, lateral and vertical, is adopted. The natural flood plains, especially the riparian zone should be restored and protected with a massive plantation drive involving riparian vegetation. No construction should be allowed in this zone. The hyporheic (self purification) zone of the Ganga should be protected. All muck/debris should be disposed away from the river in carefully identified dumping sites. No untreated sewage or source of pollution should be allowed to drain into the river and no domestic solid waste should be thrown/dumped on the banks of the Ganga. Seers, saints and other people involved in religious rituals should be refrained from submerging flowers, puja paraphernalia or immersing idols into the river. Unsustainable sand mining should not be allowed. However, sustainable river bed mining in lower stretches may be permitted, only if care is taken to replenish the material mined. Release of data on appropriate environmental flows with required water depth and velocity must be made compulsory for all hydropower projects so that downstream ecology is maintained. New policy interventions should be introduced to balance development with ecological concerns through active public participation. An integrated effort involving every stakeholder, that is, the Indian government, academia, volunteers, devotees, saints, priests, media persons, not-for-profit organisations, gram panchayats and local self government functionaries should be put in place so that all rounded efforts brings time bound results.