Officials have shut off water to LaPlace after concerns that water from Lake Pontchartrain could contaminate the water system.
WWL-TV reports Garyville and Mount Airy as well as the westbank of St. John the Baptist Parish.
Parish President Natalie Robottom says the shut off is a preventive measure to prevent contamination.
When the water levels in the lake go down, which Robottom said is anticipated once the wind changes, the supply will be turned back on.
He says 95 percent of St. John residents are without power.