Since December, the charity has been getting 10 tonnes of donations daily - a 30 per cent jump from its average collection.
Its seven collection bins islandwide have been so overwhelmed that they have to be cleared three to five times a day.
Among the most commonly donated items are clothes, toys and electrical appliances. The donations will be distributed to the charity's thrift stores, needy families and also stored up for emergencies.
Mr James Tian, general manager of Red Shield Industries, which runs the Salvation Army's thrift stores, said they have hired more relief staff and added extra work shifts to sort and process the donations.
While about 20 per cent of the donated items were new, another
10 per cent had to be thrown away because they were unusable.
They included broken furniture and electrical appliances. In the past, the charity had received broken vases and television sets, and even tattered couches stained with pet faeces.
Said Mr Tian: 'For those who inadvertently dispose their waste, thinking they are doing us a favour, we hope that they will visit our thrift store to see what useful things Singaporeans would still buy and use.'