Despite Angola's oil riches, Luanda has a skeletal infrastructure which still bears the scars of a brutal 27-year civil war that ravaged the former Portuguese colony.
The Angolan government has approved a $10m emergency relief plan to shelter, re-home and provide "other forms of assistance to citizens between now and June", it said in a communique.
This followed warnings by the national weather office that the torrential rains were set to continue until June, traditionally the end of the monsoon in the southern African country.
Job Capapinha, the Luanda's governor told an emergency meeting that his three main priorities were providing emergency relief, restoring road links and ensuring proper sanitation to stem a tide of cholera, which has claimed more than 2,000 lives across the country since February last year.
The cholera epidemic broke out in February last year in a sprawling Luanda slum and has been blamed on poor sanitation, an acute lack of drinking water and inadequate infrastructure.
"We will put people in tents or in roofed shelters. We are seeing to it that the roads are quickly cleared of water before enforcing measures to prevent cholera," governor Capapinha told a news conference late Wednesday.
Antonio Miguel Germano, a police official from Cacuaco, Luanda's worst-hit quarter, added: "There are still people who are missing. We are carrying out searches."
Other parts of southern Africa have been hit by heavy downpours, including Malawi, where at least 20 villages are under water, and Mozambique, where torrential rains have claimed five lives and left 3,500 homeless.
In March 2005, flooding in northern Angola left over 10,000 people without shelter.