With six states, including Assam and Bihar, already reeling under floods, the government on Tuesday warned of moderate floods in 12 other states as the “extreme to very heavy rainfall” over the next three days is set to sharply increase water levels of 14 rivers and their tributaries.

Already suffering with urban flooding, Mumbai (Santacruz) on Tuesday received record 298 mm (almost 30 cm) rainfall between 8.30 a.m. and 5.30 p.m. on Tuesday. The India Meteorological Department (IMD) has projected heavy to very heavy rain with isolated extremely heavy rainfall over the next 24 hours over North and Central Maharashtra.

The flood threat perception has been set high for parts of Rajasthan, Gujarat and Madhya Pradesh, as the reservoirs and dams on rivers Mahi, Sabarmati, Banas and their tributaries are already holding 90 to 94 per cent of their capacity.

Meanwhile, since Monday, 15 different regions of Maharashtra, Karnataka, Madhya Pradesh and Gujarat have been receiving significant rainfall ranging between 19 to 4 cm.

The IMD and Union Water Ministry issued an advisory regarding very heavy rainfall over the next three days in parts of 12 states, including Madhya Pradesh, Maharashtra, Gujarat, Goa, Karnataka, Rajasthan, Chhattisgarh, Telangana, Andhra Pradesh, Tamil Nadu, Kerala and Daman and Diu.

Of these 12 states, parts of Maharashtra (Mumbai) and Gujarat are already reeling under floods. Other states, including Assam, Bihar, Uttar Pradesh and Odisha, are already hit by floods, affecting millions and leaving several dead.

“Heavy to very heavy rainfall with extremely heavy fall are very likely to occur in east Rajasthan, west Madhya Pradesh, Gujarat, Konkan and Goa, coastal and ghat areas of south interior Karnataka,” said a government advisory issued on Tuesday.

“Due to this rainfall, the rivers Mahi, Sabarmati, Banas, Godavari and its tributaries, Krishna and its tributaries, west-flowing rivers south of Tapi, Cauvery and its tributaries are likely to rise and create low to moderate flood in few locations,” the advisory added.

In and around Mumbai, the very heavy rains are likely to continue for the next 24 hours, after which it would drop. The government has advised to take necessary precautions, especially in lakes areas surrounding the city.

Meanwhile, over 14 rivers and their tributaries will see rapid rise in the water level in next 48 to 72 hours.

River Mahi and its tributaries are set to affect seven districts in Madhya Pradesh, Rajashtan and Gujarat; Sabarmati river and its tributaries will affect nine districts of Rajasthan and Gujarat while Banas river and its tributaries could flood three districts of Rajashtan and Gujarat.

Floods in Narmada and Tapi basin are set to affect nine districts in Maharashtra, Gujarat and Madhya Pradesh. However the reservoirs have enough storage as they are full up to 66 to 45 per cent of their capacity, the advisory said.

Dams over Damanganga river may affect four districts, including Nasik in Maharashtra, Valsad district of Gujarat and Daman district in Daman and Diu.

Moderate to low floods are likely due to rapid rise in waters of river Godavari, Indravati and their tributaries, affecting 10 districts in Chhattisgarh, Telangana and Andhra Pradesh.

River Krishna, Tungabhadra and its tributaries are likely to rise in 12 upstream districts, including Satara, Kolhapur, Pune, Sholapur in Maharashtra and others, including Ballari district of Karnataka.

The advisory also issued caution for seven other districts in Maharashtra, Goa and Karnataka due to rise in west flowing rivers. Cauveri and its tributaries are also set to rise affecting four district of Karnataka and Kerala, though the ministry claims that the reservoirs there have efficient storage.

River Bhavani and Moyar are also set to affects part of Tamil Nadu, the advisory said, adding that in Tamil Nadu the threat of floods is not immediate.