Chennai, Oct 10: The Tamil Nadu Water Resources Department on Sunday issued a flood alert in Chennai suburbs following heavy rains and as the Poondi or Sathyamurthy Sagar Reservoir, which is the main drinking water source for Chennai, is expected to reach its full capacity.

With the rising water level, the reservoir has commenced releasing surplus water since 2 p.m. on Sunday.

The Department has already informed the administration of Tiruvallur district to relocate people living close to the banks of the Kosathaliyar river, including people living downstream in Manali and Ennore.

According to a Department statement, the Poondi dam has a storage level height of 35 feet and with the water expected to touch a height of 34 feet, surplus water would be discharged.

On Sunday, the water level has already touched 33.95 feet and if there is a further increase of flow due to incessant rains, more water would be released in phases.

The IMD had also forecast heavy rains in Chennai and suburbs including in Kancheepuram, Chengalpattu, and Tiruvallur districts for Sunday and Monday.