JOIN USThe proposed cascade of barrages will totally deprive the Hilsa from accessing its spawning grounds and the fish may become extinct.
The government proposes to make a cascade of barrages every 100 km on the Ganga from Allahabad to Haldia. ‘Locks’ will be made that will enable large 4500 ton ships to cross the barrages. The Union surface transport minister Nitin Gadkari said at a meeting that the cost of transport by road is Rs 1.50 per kilo, by rail Re 1.00 per kilo and by waterway Re 0.50 per kilo. Movement of goods on the Ganga waterway will reduce the cost of transport and help push the growth rate.
There will be environmental and cultural costs, however. The barrages will convert the Ganga into a number of large lakes of 100 km length each. The ships will cross the barrage through locks but the fish will not be able to cross them. Many fish migrate long distances to their spawning grounds.
The famous Hilsa mainly inhabits the sea. It migrates up to 1,000 km upstream into the river and lays eggs. These eggs float down the river to the delta. Here they mature and fishes come out. These little fish go into the sea. Here they gain wait and again migrate upstream to lay eggs.
This upstream migration has already been badly affected by the Farakka Barrage. The Hilsa was known to travel up to Allahabad previously. Now it can move only up to Farakka where its pathway is blocked by a stone wall. The proposed cascade of barrages will totally deprive the Hilsa from accessing its spawning grounds and the fish may become extinct.
This is just one example. Decline in the fisheries will impact the water quality of the Ganga. The fishes not only provide food. They also clean up the water. They eat the carcasses and twigs and other organic material. Thus we find large fishes merrily swimming in clear waters in holy places such as Shringeri in Karnataka. Extinction of the fishes will reduce, if not eliminate, this cleansing function and water quality will deteriorate.
The rivers bring not only water but also sediments. The Nagpur-based National Environment Engineering Research Institute (NEERI) has found that sediments of the Ganga contain high levels of copper and chromium. These metals have bactericidal qualities. The sediments also contain minute levels of radioactive thorium the functions of which are not understood as yet.
The presence of these bactericidal qualities in Ganga is dependent on the Himalayan sediments reaching the lower stretches. These sediments will be trapped in the barrages and downstream Ganga will be deprived of their beneficent qualities.
Another factor that imparts ‘self-purifying’ qualities to the Ganga waters is the presence of wide-spectrum coliphages. The coliphages are beneficent bacteria while coliforms are harmful bacteria. Many hundreds of types of both are found in river waters. Normally one type of coliphage eats up one specific type of coliform.
Beneficent bacteria
The specialty of the Ganga coliphages is that they are wide-spectrum. One coliphage eats up many types of coliforms. These coliphages stick to sand particles and remain dormant for long periods. They become active whenever they sense the presence of coliforms. They impart ‘self-purification’ quality to the water of the Ganga. Problem is that the sand particles on which the coliphages stick will not flow beyond Allahabad after making of the barrages. The Ganga will no longer self-purify itself in the lower stretches.
Trapping of the sediments will also impact the territory of India. The plains from Haridwar to Haldia have been formed by the sediments brought by the Ganga from the Himalayas. This heavy influx of sediments has counteracted the cutting action of the sea. The sea has a natural hunger for sediments. It east up the land to meet this hunger. Thus we find that most seashores are stony.
This hunger was earlier satisfied by the sediments brought by the Ganga. That led to creation of new land. This process of land formation has been reversed after making of the Bhimgoda barrage on the Ganga in 1850s and Tehri Dam and barrages at Bijnor and Narora after Independence.
As a result the sediments are largely trapped and do not flow to the sea.
The hunger of the sea is not satisfied and the sea has started cutting into the land of India to meet its needs. The Ganga Sagar Island has lost about three kilometers land in the last few decades. Making of the proposed barrages will accelerate this process and we may see much more land going into the sea.
The NDA-II government had made an electoral promise to maintain uninterrupted flow in the Ganga. That was welcome. Making of the proposed cascade of barrages is blatant reversal of its electoral pledge. The government is trying to wriggle out of this contradiction by redefining ‘uninterrupted.’
The people are now being misinformed that releasing waters from the barrages will maintain ‘uninterrupted’ flow. Even a release of 100 per cent of the incoming water will not make it uninterrupted. The water from the tubewell is different than water from the same tubewell stored in a tank. The negative environmental impacts listed above will not be mitigated by releasing these flows.
I am not against using the Ganga as a waterway. The way forward is to facilitate the movement of small ships not only up to Allahabad but up to Haridwar. The need is to decommission Farakka, Kanpur, Narora, Bijnor and Haridwar barrages so that this movement can take place.
Water can be abstracted from the river for irrigation by making a partial obstruction and removing a part of the water as was done at Bhimgoda earlier. Other examples of abstraction of water without making a barrage across the river are available from the old Tajewal