Jefferson Parish officials say winds from Hurricane Isaac have downed power lines and trees in the New Orleans suburb and heavy rainfall has caused minor street flooding.
Spokeswoman Kriss Fortunato said no injuries had been reported.
Power provider Entergy Corp. said about 164,000 customers were without power early Wednesday.
Grand Isle, the barrier island at Jefferson's extreme southern tip, was hit hard by the storm as it wobbled ashore overnight.
Heavier damage was expect there although most residents evacuated ahead of the storm.