The India Meteorological Department has forecast more rain.
Some 20,000 people have been displaced and 260 relief camps have been set up.
One column of Army from Pangode Military Station under the leadership of a Captain carried out the relief operations in Adimali area in Idukki district.
Now, there fears that water released into the Periyar river from a reservoir may cause it to flood its banks in the districts of Idukki and Ernakulam (which includes the city of Kochi). Fifty-seven tourists including 24 foreigners were stranded in the hill station of Munnar.
Father Jose Plachikkal, spokesman for the worst-affected Idukki Diocese, said Church people have joined local authorities in accommodating people displaced by floods, landslides and the opening of the dams. Tourists have been barred from entering the district as roads caved in at many places, reported PTI.
A red alert has been issued in Wayanad in the wake of rain havoc.
In Thiruvananthapuram, Chief Minister Pinarayi Vijayan held a review meeting with top officials and lauded the defence forces for their help. "The service of doctors has been ensured in the camps". With the water level at the Idukki dam fast rising, two more shutters of the dam were also opened, said a Kerala Minister.
Navy's southern command was put on alert after the water level in Periyar river rose amid concern that parts of Wellingdon Island in Kochi could be inundated. He has also cancelled all his public functions till Sunday to monitor relief work.
Meanwhile, schools in affected districts remained shut on Friday.
Two NDRF teams from Vijayawada and two teams of Army Engineering Group from Bangalore and Hyderabad have been transported to Calicut, the spokesperson said.
Union minister Alphons Kannamthanam said he discussed the flood situation in Kerala with Home Minister Rajnath Singh this morning.
"Several rescue and emergency teams have been sent to the affected districts", Kerala relief commissioner P.H Kurian told AFP.
The airport would probably be water-logged if the water from Idamalayar and Idukki dams reach Ernakulam, say sources. The Tamil Nadu government had earlier announced a contribution of Rs 5 crore towards relief operations.
With no reduction in the inflow and the catchment area receiving heavy rainfall for the past 24 hours, the KSEB authorities and the district administration have planned to increase the amount of water being discharged from the reservoir to 600-700 cumecs (6,00,000 -7,00,000 litres per second), step by step.
At 12.30 p.m. on Thursday, the water level crossed 2,399 metres, and one of the shutters was opened after a gap of 26 years.
The monsoon, which lasts roughly from June to September, has claimed more than 70 lives across the state this year and damaged crops worth millions of dollars.