Flood control barriers will be installed in at least 20,000 flood-prone basement apartments in Seoul by June, the government said Thursday, as the country is expected to face more extreme summertime weather this year.

The underground flats, also known as "banjiha," have been identified as most vulnerable to flooding under an ongoing government inspection of 220,000 banjiha that will end this month.

It comes as the city is bracing itself for the rainy season as forecasts predict El Nino is set to return this year, bringing with it warmer temperatures and more intense weather events.

Last August, the worst flash flood in more than a century in the greater Seoul area took 12 lives. Among them were four -- including an entire family -- who stayed in their apartments below ground. Most of the 2,400 people displaced by the floods were living in basement apartments.

The torrential downpour and flooding caused 68.4 billion won ($51.8 million) in financial damages.

The latest measures are part of the Seoul Municipal Government's plans to phase out basement apartments.

Other initiatives announced on Thursday include providing residents in basement apartments with financial support to move homes.

Starting this year, people on low incomes who live in basement apartments in Seoul will be eligible to have their housing deposits fully covered with interest-free loans when moving into public housing, according to the municipal government. The same kind of loans will be offered to support their relocation into private rental housing, up to a limit of 50 million won.

Also, up to 400,000 won will be provided to those intending to move out of basement apartments for the cost of moving and buying necessities.

Seoul also announced that over 2,300 people from at least 954 households living below ground will be alerted by neighbors and public servants in case of flash flooding.

Earlier in April, the city-run Seoul Housing and Communities Corp. announced plans to buy 3,450 flood-prone banjiha apartments from residents and to finance their moving costs. Banjiha apartments that were flooded in southern Seoul will be given priority.