Krishna and Godavari rivers are in spate, while the first flood warning was issued at Prakasam Barrage here on Tuesday.
Andhra Pradesh State Disaster Management Authority (APSDMA) has alerted people in the downstream of the Prakasam Barrage.
Due to massive inflows following incessant rains upstream, the water level has increased at the barrage across the Krishna River.
Officials said the inflow of 4.01 lakh cusecs at the barrage was being let out downstream. The inflow is likely to reach 6 lakh cusecs by Tuesday evening.
Massive inflows from upstream reservoirs, driven by heavy rain in catchment areas, prompted authorities to lift 69 out of 70 crest gates to release surplus water into the sea.
All major dams on both the Krishna and Godavari were receiving massive inflows. The inflow at Srisailam dam across the Krishna River in Andhra Pradesh was 3.42 lakh cusecs. The authorities were releasing 4.04 lakh cusecs downstream. The inflow and outflow at Nagarjuna Sagar dam in Telangana were 3.71 lakh cusecs and 3.98 lakh cusecs, respectively.
The water level in Godavari was also rising sharply at Bhadrachalam in Telangana. The water level stood at 36.6 feet.
The inflow and inflow at Dowleswaram Barrage near Rajahmundry in Andhra Pradesh was 8.23 lakh cusecs.
APSDMA Managing Director Prakhar Jain has urged people living along the Krishna, Godavari and Tungabhadra rivers to remain alert. He cautioned people against crossing overflowing streams and canals.
Meanwhile, the Indian Meteorological Department (IMD) has forecast extremely heavy rainfall over coastal Andhra Pradesh on Tuesday.
The low-pressure area over west central and adjoining northwest Bay of Bengal off north Andhra Pradesh and south Odisha coasts intensified into a well-marked low-pressure area and crossed the Odisha coast at Gopalapuram on Tuesday.
Under the influence of a low-pressure area, isolated places in the north coastal Andhra received heavy rainfall. Squally winds with a speed of 35-45 km are likely in the region.
APSDMA has cautioned fishermen against venturing into the sea and appealed to people to remain alert.
Meanwhile, G. Vijayalaxmi, Special Chief Secretary, Disaster Management, held a teleconference with district Collectors in view of the floods in the Krishna and Godavari rivers.
She reviewed the situation with Collectors of 13 districts along the course of the two rivers. She directed them to take all measures to prevent any untoward incident.
The Collectors were asked to alert people of low-lying areas and, if necessary, shift them to relief camps.
The Special Chief Secretary directed that the teams of National Disaster Response Force (NDRF), Special Disaster Response Force (SDRF) should be kept on standby.
The officials were also directed to ensure sufficient stocks of essential commodities, medicines and sanitation material.