The Bengaluru, Mysuru and Mandya regions of Karnataka may soon face severe water shortage as the water levels in the Krishnaraja Sagar dam and the Kabini reservoir have dropped drastically.
The water level on Monday stood at 78.96 ft, while the maximum capacity of the dam is 124.8 ft. The live storage level of the dam is 1.955 TMC ft, after which the government will have to ask the irrigation officials to draw water from the dead storage, a TOI report states.
At 2.32 TMC ft, the Kabini reservoir has less than half the water it held last year, and just over one eighth of its total capacity. Bengaluru alone requires 2 TMC ft water every month, TNIE reported.
The inflow had not crossed 300 cusecs in the last two months, which is the same amount released into the river according to the Supreme Court order.
The dam authorities admitted to being ill equipped to draw water from the bottom of the reservoirs with letting the process affect the dam, media reports suggested.
Dead storage in the two reservoirs is when the water touches 60ft, where only 4.4 tmcft water is available. In addition to the drinking water supply, the rapid rate of evaporation, and the water being released to Tamil Nadu, dam officials fear that the reservoirs' water levels will soon deplete, the report says.
The water levels will reach dead storage levels sooner if the pre-monsoon showers too fail. It is dangerous to draw water from the dam at dead storage level as it will harm aquatic life.
But even as the threat of water shortage looms over Bengaluru, BWSSB officials are planning to drill more borewells in the city, TNIE reported.
There are around 7,920 borewells in BBMP limits currently, of which 938 are non-functional. The BWSSB is now planning to revive these borewells. In addition, the agency plans to drill 200-400 new borewells depending on the demand. The process has been slow as there are no bidders to drill the borewells despite the call for several tenders.
Bengaluru’s borewells – whether authorised or not – have brought down the groundwater to dangerously low levels. In the state capital and surrounding areas, groundwater is available at around 1,000 feet.
The BWSSB had written to the Cauvery Neeravari Nigama regarding a possible crisis. Bengaluru requires 1,400 MLD of water every day, but the Board is able to supply only 1,250 MLD, as the water level in the KRS dam is low.
BWSSB officials have been spreading awareness among people for need of water conservation methods and urge residents to install rainwater harvesting (RWH) systems. This, despite rules mandating households to install RWH systems having been in force since 2009.
According to a study by the Centre for Energy and Wetlands Research Group at the Indian Institute of Science, Bengaluru has about 9.15 lakh water connections. An estimated 1.4 lakh consumers should have installed rainwater harvesting systems but only 62,000 have done so.