Scores of scores of buses, dozens of high-water vehicles and 50 boats are evacuating at least 3,000 people in Louisiana's St. John the Baptist.

Lt. Gov. Jay Dardenne says floodwaters caught everyone by surprise, rising "shockingly" fast as Tropical Storm Isaac pushed water from lakes Pontchartrain and Maurepas (mohr-uh-PAH') into parts of LaPlace.

Rising water closed off all main thoroughfares into the parish, which is about 30 miles west of New Orleans. The water is being driven higher by south winds as Isaac passes to the west.

Dardenne says officials are speculating that when levees in other parishes along Lake Pontchartrain were fortified after Hurricane Katrina, it forced storm surge into areas that had escaped flooding in past storms.

He says "the water's got to go somewhere, and this is where it went."

With one water district flooded, the National Guard is sending two 5,000-gallon water tankers and 35,000 bottles of water to distribute to residents. State officials are sending 200 one-ton sandbags to protect the water system from floodwater contamination.