Monday, 29 July 2013

Will it be Sharavathi or Yettinahole

The lakes first and Hesarghatta and Tippegondanahalli (TG Halli) quenched the thirst of Bangaloreans. When Bangalore was founded by Kempe Gowda in 1537, he conceived a system of interlinked tanks and lakes that not only provided water to the residents but also acted as a flood control mechanism.
When the British decided to shift their Cantonment from Srirangapatna to Bangalore in 1806, they realize that Bangalore did not have any natural water nearby to fulfil the water needs of a growing City. They then built the Ulsoor lake and also other water bodies such as Sankey (1882) and Millers Tanks (1873).
Soon, the Mysore Government too realised that the tanks planned by Kempe Gowda were insufficient to provide water to the pettah area and they planned the Hesarghatta reservoir across the Arvakathy.
When the Hesarghatta reservoir too failing to fully quench the thirst of Bangaloreans and drying up in 1925, the Mysore Government planned the TG Halli reservoir. Unfortunately, the Hesarghatta has completely gone dry and the TG Halli too is going the same way. The only alternative for the State Government was to tap the Cauvery which was more than 90 kilometres away from Bangalore.
With the Cauvery panel limiting the quantum of water to Bangalore, the State Government has now been left with no alternative but to look for alternatives to provide water to a city which is now the fourth largest metropolis in India.   
The State Government has now planned to reduce the dependence on Cauvery by tapping another river to provide drinking water to Bangalore and this is the Sharavathi river.  
The Sharavathi is a west flowing river which takes it birth in the Western Ghats. It is better know for being the source of Jog Falls. A high-level committee appointed by the previous Government has suggested a few days back to the present Congress Government that the Sharavathi could be harnessed to augment the exisiting water supply to Bangalore.
The committee had been appointed to identify possible water sources to redress Bangalore’s water needs.
The committee was headed by H N Thyagaraj, former chief engineer of Bangalore Water Supply and Sewerage Board (BWSSB) and it comprised ten other members.
The committee has suggested five options to the Government and of them it concluded that the Sharavathi would be the most viable one.  
What makes the Sharavathi option ideal is that its waters are mainly used for producing power and also for agriculture. If the waters are to be diverted to Bangalore, then the State must be ready to reduce the power generation from Sharavathi. So, it means bartering water for power.
Sharavathi is at least 300 kilometres away and the water will have to pass through regions at a lower elevation than Bangalore. The committee feels that water can be brought from Linganamakki reservoir that is fed by Sharavathi to Hesaraghatta reservoir in Arkavathi catchment area.
The water can then be pumped into Bangalore. The committee has also recommended the manner in which the water has to be pumped. It says water has to be pumped first from Linganamakki reservoir to Yagati, which is 130 km away. It will then be pumped into Arkavathy, 170 km away, by using gravity. Though pumping is inevitable, the power consumed will be much lesser than what is being used currently in case of pumping the Cauvery.
Since Linganamakki has a capacity of 150 thousand million cubic feet (TMC), the committee feels that at least 10 TMC could be easily pumped into Bangalore. This could be increased by 10 TMC once every ten years.
Another option is to get water from Yettinahole. This option had been suggested by the Paramashivaiah committee. The Government now has no other alternative but to tap either the Sharavathi or Yettinahole, another river which originates in the Western Ghats, for providing water to Bangalore.
The Government realises that all the four phases of Cauvery are over and the river cannot be tapped for any more water. It has to approach the World Bank or other financial institutions for finance and these institutions would fund the scheme only if the source of water is identified.  
Former BJP minister Katta Subramanya Naidu had contemplated linking the Almatti to Bangalore so that the city gets 24/7 water.
Irrigation experts point out that the entire river system of  Karnataka yields 3440 tmc ft of water and the West-flowing rivers account for 2,000 tmc ft annually and this comes to 58 per cent of the total yield. Due to the narrow coastal belt in Mangalore, Karwar and Udupi, a major portion of the water goes into the sea and it is this excess that has to be tapped.
However, tapping these waters is not technically viable or financially feasible. Besides, any such diversion could cause large scale environment harm and destroy the fragile ecology of the Western Ghats. So the best option is to only tap the west flowing rivers on the upper reaches of the Western Ghats and this would come to 0.54 tmc ft of water.
Another plus for such a diversion is that the Western Ghats report high levels of rainfall and this bounty of Nature can be tapped. However, it should not be forgotten that the Western Ghats is a biological reserve and home to thousands of animal species including at least 325 globally endangered species.
Another problem for using Yettinahole to quench Bangalore’s thirst is that it is a major tributary along with Kumaradhara of Netravathy.
Besides, the Netravathy’s origin itself is Yettinahole. It is only later that the Kumaradhara joins the river. If the Yettinahole is diverted, it means diverting the Netravathy itself. The Netravathy is the lifeline of the coast and people living there should get the first right over it.

Moreover, river water has to flow to the sea to sustain aquatic life and also to retain the ecological balance. What could be done is to reduce the excess flow into the sea and use this balance to meet Bangalore’s water needs. But, many towns and villages in Mangalore district already suffer from water shortage.  The question is how will the Government tackle this problem. There has to be a coordinated and comprehensive approach to resolve this issue.      

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