The tunnel is near Kakkattukada on the Kattapana-Elappara route.
The northeast monsoon rains or thundershower is likely to occur at most places in Kerala for the next two days.
Light to moderate rain is likely to intensify on October 29 and 30 in the state and IMD sounded yellow alert for several districts.
Spread over an area of 1288.31 square kilometres, it is known for its biodiversity and the density of tigers here is the highest in the world.
The summer rainfall deficit due to El Nino could make staples such as sugar, pulses, rice and vegetables more expensive and lift overall food inflation.
The highest deficient monsoons so far recorded in the state’s history are in 1918 and 1976, respectively.
Alappuzha, Kottayam, Ernakulam, Idukki, Thrissur, Malappuram, Kozhikode, Kannur, Kasaragod are under yellow alert today.
This year is the 13th consecutive delayed Monsoon retreat.
The electricity board has hinted that it might be forced to impose load shedding in the present scenario.
The primary reasons for below-normal rainfall are El Nino and unfavourable phase of the Madden-Julian Oscillation (MJO)