TORRES, Brazil (AP) — A mayor in southern Brazil asked residents to ration water Tuesday in a state capital where some 80% of the population is without running water, a week after massive flooding that has left at least 90 people dead and more than 130 missing.

Efforts were continuing to rescue people stranded by the f loods in the southern state of Rio Grande do Sul, as more rains were forecast for the region into next week. The capital, Porto Alegre, has been virtually cut off, with the airport and bus station closed and main roads blocked due to the floodwaters.

Five of the city’s six water treatment facilities aren’t working, and Porto Alegre Mayor Sebastião Melo ordered that water be used exclusively for “essential consumption.” Local shops have also been short on water supplies.

“We are living an unprecedented natural disaster and everyone needs to help,” Melo told journalists. “The shortage is real and it will take some time until it goes back to normal.”