Treated wastewater could be one solution to the distress ahead. A look by S. Vishwanath
It is the beginning of the year and already 174 taluks in the State have been declared as affected by drought by the Karnataka State Disaster Management Centre. The complete failure of the north-east monsoon compounded by the less rains of the later part of the south west monsoon has led to this situation. The consequences on rural areas dependent on agriculture is likely to be severe with borewells drying up in many places. Fodder availability will become a challenge for livestock and even drinking water will become dependent on tankers as summer approaches.
For the cities and towns in the Cauvery basin, domestic water availability should not be a problem. The major sources of drinking water – K.R.S, Kabini and Hemavathy reservoirs – have more in stock as compared to last year. Only the Harangi reservoir has less water than the same day last year. With judicious management, it should be possible to manage the regular supply till June 1 and beyond when the next monsoon is scheduled to arrive.
Those dependent on borewells for water or on tankers will find it tough as summer starts reducing groundwater levels in the aquifer.
In a curious case the wastewater streams from the cities and towns, full of nutrients, become perennial waters for farmers to use. In the Vrishbhavathi and the Dakshina Pinakini river stretches, wastewater flows 24/7 and 365 days a year. Farmers pick up these waters and are growing crops like millets and even paddy.
Near the Lakshmisagara tank and Udappnahalli and Narsapura tanks, agricultural activities were in full swing, as these tanks were being filled with treated wastewater from the K and C valley. The government’s thinking is to pump 400 million litres per day into a series of tanks, filling them up eventually. The Supreme Court has stayed this pumping, according to newspaper reports. Hopefully the government has put in place systems to ensure that the quality standards prescribed by the Pollution Control Board are met and that the health risk to animals, livestock, farm produce and for drinking water is avoided.
One saw full wells in the surrounds as the wastewater starts to recharge the aquifer. Fishing activity was also going along in these tanks. If done well and correctly, treated wastewater will flow into tanks of Chikkaballapur and Anekal too as well as Ramangara and has the potential to drought proof at least those tanks that receive adequately treated wastewater.
In Mexico City and in Amman, wastewater irrigation is practised on a large scale. Lessons need to be learnt from these experiences and systems put in place for reuse of treated wastewater, especially for agricultural purpose. As cities grow, the consumption of water will only increase and the generation of wastewater too.
Cities and towns need to invest in keeping industrial effluent separate from domestic wastewater, collect all the wastewater in piped networks, treat them adequately, ensure the absence of heavy metals and bacteria and then make arrangements to send them into the hinterland for agricultural reuse.
Drought has many dimensions but treated wastewater could be one solution to the distress. Using this wisely would be water wisdom.
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