NEW : as many as Mississippi counties are declared major disaster areas . After gates are opened , Beauvais said , it would take about three days for the water to fully reach Morgan City , a town of about 12,000 near the coast . NEW : Authorities predict a major spillway could be opened within May 23 . The crest is estimated to be in Louisiana on a week , Louisiana governor says . the National Weather Service estimates damage to state 's agriculture to top $ 500 million .
NEW : as many as Mississippi counties are declared major disaster areas . NEW : Authorities predict a major spillway could be opened within May 23 . The crest is estimated to be in Louisiana on a week , Louisiana governor says . the National Weather Service estimates damage to state 's agriculture to top $ 500 million .