MIAMI - Three major sewage plants in South Florida could be reduced to shrinking islands in less than 50 years due to climate change, according to a group of climate scientists.

The scientists believe rising sea level will threaten some of the region's most vital facilities. It will also flood land, streets and neighborhoods nearby, The Miami Herald reported Sunday.

The scenario was drawn up by five experts from the University of Miami, Florida International University and Florida Atlantic University retained by Biscayne Bay Waterkeeper. The clean-water advocacy group is challenging Miami-Dade's $1.5 billion plan to repair the county's troubled sewage system.

Most of the money would go toward repairing the county's aging, spill-plagued sewage system. Biscayne Bay Waterkeeper contends it would make more sense to move the plants to more protected inland sites.

"At some point, and I hope it's this year, Miami-Dade government and everybody has to start truly recognizing that we're in for it," University of Miami geology professor Harold Wanless said.