Heavy rains lashed Rio Grande do Sul last September as an extratropical cyclone caused flooding that killed more than 50 people.
This came after more than two years of continuous drought due to the La Niña phenomenon, which produced only scant rainfall.
President Luiz Inácio Lula da Silva traveled to the state on Thursday to tour affected sites and discuss rescue efforts with the governor.
In Brasilia, Lula vowed on Friday that his government would support local rescue and reconstruction efforts.