The Kabini reservoir, considered to be the lifeline of Bangalore and the main source to meet the needs of Tamil Nadu, has slipped to the lowest level in the past 10 years. The reservoir level has fallen to 2,248.10 ft.
It had previously hit 2,248 ft as against the maximum 2,284.10 ft when the state witnessed a severe drought in 2003.
The Kabini reservoir has a storage capacity of 19.5 tmc ft, of which 6.5 ft is in dead storage. If there are no rains in the next two months, the reservoir will touch an all-time low and will affect the ecology, wildlife and the drinking water supply to major towns.
The water storage would have slipped further if the Irrigation Department had not stopped the water supply to the irrigation canals in December 2012.
Officials attribute the present situation to the failure of monsoon and shortage of rainfall in Wayanad, the Kabini catchment in Kerala.
Although the water level had dipped in 2003, irrigation officials had then ensured water was provided for two crops in Kabini achkat.
But this year officials have given water to only one semi dry crop and farmers were warned against growing paddy or sugarcane as most of the water was released to Tamil Nadu following the Supreme Court directions.
An irrigation official, pleading anonymity, said they can release 2.75 tmc ft of the 6.5 tmc ft (in dead storage) in the worst scenario.
But, they fear that this would affect the wildlife, including thousands of elephants and other animals that depend on water from Kabini.
The release of water from the sluice gates will not any have pressure following the fall in the water level in the reservoir.
The reservoir level was 2,266.25 ft last year with 800 cusecs of water for Ullahalli-Rampur irrigation canals, with an inflow of 36 cusecs.
Irrigation officials have released 100 cusecs to meet the drinking water needs of Mysore, T Narsipur, Nanjangud and Saragur town.