Compiled by Rajeev Toppannavar and others.
Mandovi river also known as Mahadayi, originates in the Western Ghats of Khanapur taluka, Belagavi district. As they plunge towards the coastal strip, they pass through deep gorges creating spectacular waterfalls. The Mahadayi river follows this pattern and is a comparatively small stream with a total length of just about 87 km.- 35 kms in Karnataka and 52 kms in Goa. Both, the Malaprabha and the Mahadayi run parallel to each other for some distance but flow in the opposite directions.
As many as 75 big and small streams join the Mahadayi at various stages increasing its volume and velocity. The main tributaries of the Mahadayi in the upper and middle catchment areas in Karnataka are small streams of an average length of 5 to 10 km. and as one follows the flow, they are: Right Bank: Bhandura Nala near Kongla, Singar Nala, Doli Nala, Kotni Nala, Irti Nala, Bail Nadi. Left Bank: Pansheer Nala, Madhuhalla Nala.
These two streams arise on the crest line astride Talewadi and rush down on either side of the Barapedi caves within a km of each other near Krishnapur in the lower loop.
North of the loop near Kankumbi in the catchment area of Malaprabha river, two potent streams – Kalasa and Surla (Bhandura nala) join east of Chorla and flow across the crestline as Surla river in Goa emptying into the Madei above Valpoi at Nanode in Goa. These two streams are very important and major streams that feed the Mahadayi river.
About thirty villages scattered over the area remain poor, ill-served and rejected in the midst of thick resource-rich forests.
Vertical rock cave ampitheatres of Krishnapur near Goa border are gigantic wall formations 1000-1500 ft in height. The caves are extremely difficult to access, have remained untouched and are nature’s secret providing haven to a large number of floral and faunal species.
The steep drop of over 300 metres near Krishnapur and over 400 metres near Bhimgad to the valley down below is breathtaking. Thereafter, the land rises to the north of the Mahadayi to peaks of about 700 metres at Kedi Paunda and Tamadi Mokh.
12 km from Jamboti is Vajra Poha waterfalls, here the river Mahadayi is joined by two other streams – Maradha nala and Pansheer nala, creating the magnificent Vajra Poha waterfalls. The Mahadayi takes a leap of over 150 ft. with rapids above and below the waterfalls.
The Mahadayi/Mandovi river valley is one of the few surviving pockets of the “Last Wilderness” in the world and the main watershed for Goa’s rivers. It’s a pity that instead of saving and protecting it, it has now come under the axe for the sake of “development”!
This is mainly a pictorial documentation which attempts to bring out the natural wealth of this valley – its streams and waterfalls, its forests and wildlife, its people and the millennia old civilization and settlements on the banks of the river Mandovi in Goa all of which stand to be decimated due to Karnataka’s river valley project which proposes to divert a sizeable quantum of water from the Mahadayi to the Malaprabha river in Belgaum district of Karnataka. But the project is far more ambitious. It includes building as many as 11 dams on the Mahadayi and its tributaries in a small area of 50 sq km along with hydroelectric projects.
The project will submerge a vast area of thousands of acres; most of it will be thick forested area. The tribal living in the area will be displaced. Once these forests are destroyed there will be a drastic change in the ecology of the valley ruining its forests, wildlife and all its natural wealth. The core catchment area of the Mahadayi lies in the heavy rainfall, thickly forested, approximately 200 sq km of mountain topography of Khanapur taluka, barely 10 km upstream of Valpoi in Goa, where Karnataka’s diversion and hydroelectric dams are to come up.
The Mahadayi is a comparatively minor stream that arises in the Western Ghats and the river valley is a large pocket of dense, pristine monsoon forests, one of the richest reservoirs of biodiversity in the world that reflects complexity in plant, animal, bird life and is home to some rare endangered species of bats.
Mahadayi river valley is in the news because of the inter-state water sharing dispute between Karnataka and Goa. The Mahadayi Valley has been facing many threats. Illegal felling of trees and illegal mining has been going on for decades. Large scale plantation of exotic species (acasia & mangium) has also been damaging the ecology of the area.
With water diversion and hydroelectric projects, the Mandovi river, Goa’s life-line, faces imminent threat of choking because of the reduction in water flow, siltation and disruption of its ecology due to change in its profile – perhaps being even reduced to a trickle in the summer months and possibility of seismic disturbances.
The main threat that is now looming over the valley is the Karnataka Government’s plans to divert a large quantum of water from the Mahadayi river and its tributaries to the Malaprabha river basin to help the acute water scarcity faced by the region in the Malaprabha basin. But as long as the exploitation of water resources continues in the Malaprabha region, no matter how much water and from where it is diverted, the Malaprabha valley is likely to face the same situation in the near future.
But the project is far more ambitious. It includes building as many as 11 dams on the Mahadayi and its tributaries in this small area along with hydroelectric projects. The project appears to aim at impounding a large portion of waters from the Mahadayi and its tributaries that flows into Goa, which will mean that Karnataka retains and controls all the dams and the Mahadayi waters.
It is estimated that this project will submerge a vast area amounting to about 3,000 hectares; most of it will be the thick forested area on Karnataka side of the valley. Once these forest are destroyed there will be a drastic change in the ecology of the valley reducing the rainfall, ruining its forests, wildlife, and all its natural wealth. The core catchment area of the Mahadayi lies in the heavy rainfall (3800mm-5700 mm per annum) thickly forested, approximately 200 sq. km of mountain topography of Khanapur taluka barely 10 km. upstream of Valpoi in Goa. A very large quantity of water that flows down the Mandovi all the year round originates in the streams and rivulets around Kankumbi, Jamboti, Talewadi, Gavali and Hemadga villages where Karnataka’s diversion and hydroelectric dams are to come up. The Mandovi river, Goa’s lifeline, faces imminent threat of choking because of the reduction in water flow, siltation and disruption of its ecology due to change in its profile – perhaps being even reduced to a trickle in the summer months.
Every variation in the Mahadayi water level will be crucial for ecology, forests, wildlife, agriculture, drinking water, fishing and transportation.
Disclaimer: Main aim of the article which has been compiled by Rajeev Toppannavar from various sources is to create awareness of the impact the 11 dams will create once they are built.