Rajasthan, Gujarat, Maharashtra and Goa, all located in the west of India, have rivers belonging to several different basins. With the exception of rivers in Rajasthan that drain into the Yamuna basin, the other rivers in these states either drain into the Bay of Bengal via the peninsular basins or run from the Western Ghats and into the Arabian sea.
Rampant sand mining in Rajasthan has affected the water retention and seepage into subsurface channels. Banganga river, which flows near Jaipur, is the biggest casualty to encroachments and sand mining. In Banganga basin, Jamwa Ramgarh reservoir, which hosted the rowing events of 1982 Asian Games, has been dry for the last 10 years. In Goa too the unregulated mining of alluvial sand has damaged the river ecosystem impacting traditional fishermen. Many of the small rivers of Goa are on the verge of extinction.
Chambal, one of the two perennial rivers of Rajasthan, has been reduced to a stagnant, shrunken sliver beyond the Kota barrage as it is channelised to meet the needs of Madhya Pradesh and Rajasthan. Lift irrigation schemes at Dholpur and Pinahat have furthered the decimation. The river recovers with the Kali Sindh and the Parbati river flowing in.
In Gujarat, most of the rivers, including the Sabarmati, are dumping grounds for industrial waste. Mahi river is on the verge of extinction due to pollution and salinity. Mahi estuary is badly affected by industrial effluents. The 32-km long journey of Tapi river through Surat city is mired with illegal drainage lines that dump domestic sewage and toxic waste from industries. The industrial patch along the southern bank of the Narmada river uses its water and releases waste in its tributaries. The west-flowing rivers of Saurastra and Kutch region are no better. The tubewells in the Jetpur town of Rajkot district spew red-coloured water containing harmful chemicals due to contamination of the Bhadra river.
Twenty-three percent of the rivers of Goa are critically polluted. The Baga river that emerges from the forested areas of Assagao of Bardez is heavily polluted today, thanks to the increase in tourism resulting in the intense garbage and sewage dumping. Some of the private resorts have started boating and cruising facilities for the tourists, affecting the natural drainage of the river.
The Kalpasar project which will have a large dam is bound to harm the ecology of Narmada, Sabarmati, Dhadhar, Mahi and some of the Saurashtra rivers.
Salaulim dam, built on the Salaulim river, which supplies drinking water to 55 percent of Goa’s population, has more than 15 mining leases in the catchment of its reservoir. River Khandepar, which is the source of drinking water to 30 percent of Goa’s population, has 21 mines within its catchment. The silt often chokes the filter beds of the water treatment plant. The Bicholim river, once navigable, has lost its navigability on account of siltation. The main rivers of Goa, the Mandovi and the Zuari are also heavily polluted due to mining. The Zuari has 10 operating mines in its catchment and the Mandovi has 27 mines depositing 70,000 cubic tonnes of iron particulates every year in the river.
Krishna, one of the important east-flowing peninsular rivers, has undergone extensive dam construction. Water parched stretches of the Krishna river downstream of the dams are further being polluted by untreated sewage, effluents from sugar distilleries and other industries. Maharashtra has also been experiencing floods in Upper Krishna basin caused by the backwater effect of the Alamatti dam built in the Bijapur district of Karnataka.
Studies show that the flow of the Bhima river which makes a significant contribution to the Krishna has reduced substantially in the period between 2001 and 2011 from dam construction and allocation of water. There is no allocation for environmental flows for the river downstream of any of the dams.Thus, the rivers below the dams are almost entirely dry and are unable to sustain life.
Tata hydropower dams at the origin of the Mula-Mutha sub basin have been diverting water of the Bhima basin to water surplus Konkan for power generation, even in severe drought seasons. Various citizens groups staged jal satyagraha in May 2016 demanding nationalisation of six dams so that their water can be used by the general public. The high court also passed a strong order recommending the release of water stored in the “private dams” and sources for drinking water purposes of the drought-hit region. Unfortunately, no water has been released yet.
Godavari is also fettered in many dams all along its length and across its basin which have been responsible for human sufferings, ecological impacts, livelihood struggles and conflicts. Domestic sewage of urban centres is one of the principal pollutants of Godavari. In the Wardha basin however, the river is also critically polluted due to coal mining and thermal power plants.
The rivers of Karnataka with pollution at three to 10 times the norm for clean water bodies are cesspools of stink. As per the Monitoring of Indian National Aquatic Resources System, a part of the Central Pollution Control Board (CPCB), over 655-km length of 15 rivers in 38 spots is highly polluted. The report by CPCB also adds that “poor environment management systems in industries, such as chemicals, metal and minerals, leather processing and sugar mills, have led to the discharge of highly toxic and organic waste water”.
To read the first part of this series on the north and east rivers, click here.
The detailed state reports can be accessed at India Rivers’ Week blog