What goes west may come east now

What goes west may come east now

Quenching thirst

At last, the State Government seems to be waking up to the hardship faced by the people of Chikkaballapur and Tumkur districts due to non-availability of drinking water. With no perennial source of water to the two districts and even availability of ground water becoming a rarity, the government is considering the option of harnessing river water in other districts to meet the requirement of the water starved districts. 

Realizing that bringing water from the West flowing streams a difficult proposition, the government has zeroed in on Yettinahole river which is on the fringes of Sakaleshpur/Western Ghats to meet the drinking water demands of Chikkaballapur and Tumkur districts besides some parts of Bangalore urban district. A feasibility report has stated that 10.77 tmc of water may be harnessed.

Yettinahole is a tributary of Netravati River. It is considered for harnessing as it is encountered immediately after entering the Western Ghats. The extent of catchment area as per the study is about 65.80 sq km. The stream originates at an elevation of 1298 m above MSL (mean sea level) and it is proposed to tap the water at an elevation of about 800 m AMSL.

Karnataka Neeravari Nigam Limited, the nodal agency to implement major irrigation projects,  commissioned a study by a private consultancy to study the feasibility of diverting flood water from Sakaleshpur (West) to drought prone areas of Chikkaballapur and Kolar districts (East) that are facing acute shortage of drinking water. The ground water level in the regions has reached 1,000-1,400 ft and it has high content of fluoride and nitrate.

Tenders have been invited to prepare a detailed project report. As per the plan, the government may have to spend nearly Rs 8,000 crore to quench the thirst of the two parched districts besides parts of Bangalore urban. A budgetary allocation of Rs 200 crore has been made for the project. 

The feasibility report, prepared by EI Technologies, says that it is possible to divert Yettinahole water during the peak monsoon – June to December. Storage facilities have to be created for using the diverted water to the targeted districts.

The existing minor irrigation tanks (MIs) and new reservoirs could be constructed to store the water. In Chikkaballapur, the total live capacity of 134 tanks is 7.86 tmc and in Kolar, the capacity of 79 tanks is 4.96 tmc. Alternatively, if the diverted water is proposed to be utilized fully for drinking, independent storages may be constructed in four places.

The report has suggested four options that could be adopted for diverting the water. One of the modes is to bring the water to Chikkaballapur and Thippagondanahalli in Bangalore through pipeline. Eight to 10 tmc can fill 100 tanks. The scheme plans to utilize 0.54 per cent of the yield in the Western Ghats. Getting water from other perennial rivers close to the water-starved districts is almost impossible due to the tribunal and other constraints; it is pointed out in the report. 

The report says that the streams considered in the Yettinahole sub-basin are not gauged. The main river Netravati is gauged at Bantwal since 1971. The average annual rainfall in the Netravati catchment area is 4658 mm. The water can’t be drawn from December to May as the flow dwindles, and any diversion in those months would affect drinking water supply downstream.

The river Netravati, one of the 13 rivers in the West coast region of Karnataka originates in Western Ghats at an elevation of 1600 m AMSL and a total catchment area of 3657 sq kms. The river runs for 103 km before it joins the Arabian Sea near Mangalore.

Desilting of tanks the solution?

Holistic approach – desilting of tanks, rain water harvesting, rooftop harvesting, creating of farm ponds and Kalyanis, unclogging feeder channels among other measures are the way to tackle water crisis in Kolar and other districts, according to M V Narasimha Rao, Executive Director, Gram Vikas, an NGO, which has worked on water issues in the district for over 30 years.

Rao says he is against bringing Netravati water to Kolar as such a project is not sustainable. “Gram Vikas Mulbagal has rejuvenated a number of tanks. The purpose has been served. Kolar had managed its water requirements for centuries. Tank system had worked well. So, there is no need for bringing water from outside.”

Kolar has 2055 tanks across the district and almost all are empty, according to N Shanthappa, CEO, Kolar Zilla Panchayat.  About five to six tanks in Mulbagal have been desilted and the water level has gone up. The last year, the district received about 735 mm of rains. But it did not help farmers or increased ground water level.

“The ground water level goes up only when sufficient rains are received. But that is not happening. On Saturday, financial bids were opened to entrust desilting of 154 tanks by spending Rs 30 crore. At least Rs 30 lakh is required to desilt a tank,” he says.

Shanthappa says that even if water is brought to Kolar from outside the district, it may ease only drinking water shortage but agriculture sector continues to suffer due to paucity of water.

The storages

* To augment drinking water requirement of Tumkur
Tumkur city is now getting drinking water from Hemavathi canal which gets stored in Bugudanahalli tank. A new reservoir needs to be built to store more water

* Augmenting Chamarajasagara Reservoir (TG Halli)
Chamarajasagara is constructed across Arkavathy River. The inflow to the reservoir in 1981 was 1.76 tmc, and in 2008 it was low as 0.83 tmc. The reservoir has the capacity to store more water.

* Augmenting of Hesarghatta tank
Hesarghatta tank is constructed across Arkavathy river. The live capacity of the Hesarghatta is about 0.9 tmc. Over the past 15 years, the inflow has reduced to as low as 0.3 tmc.

* Water to Devanahalli industrial area
A good number of industrial establishments and various SEZs are planned in the North Bangalore. They require uninterrupted flow of water and there are no reservoirs for storing the proposed diverted water. 

Proposed  reservoirs
* Chikkaballapur district: A new reservoir across Kushavati river near Gudibande.
* Kolar district: The Department of Minor Irrigation has constructed a tank to impound the water across Palar River north of Bethamangala. The tank can be used to store additional water.

New reservoirs
Near Thimmasandra across Palar river which will be upstream of Bethamangala tank; a reservoir across Palar river north of the NH 7 near Tandihalli to impound 2.2 tmc of water.
* Tunnel and Pipeline arrangement
Water can be brought through tunnel covering a length of about 180 km. The tunnel will be of 6.75 m diameter. It can be bifurcated at km 158 from where a tunnel will continue up to km 180 towards Chikkaballapur.
* Environment 
Tunnel operation will have least impact on environment.

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