Grand Isle is a town in Jefferson Parish, Louisiana, located on a barrier island of the same name in the Gulf of Mexico. The island is at the mouth of Barataria Bay where it meets the gulf. As of the 2010 census, the town resident population was 1,296; during summers, the population including tourists and seasonal residents sometimes increases to over 20,000. Grand Isle is statistically part of the New Orleans–Metairie–Kenner Metropolitan Statistical Area, though it is not connected to New Orleans' continuous urbanized area.
Grand Isle's main street is the sea-side start of Louisiana Highway 1, that stretches 436.2 miles away to the north-west corner of the state ending near Shreveport, Louisiana. Crossing Highway 1's automobile causeway at the west end of the island is the only land access to or from Grand Isle. Direct access to Grand Isle's seat of parish government is away in suburban Jefferson Parish which leaves the town somewhat politically isolated.
Grand Isle has been repeatedly pummeled by hurricanes through its history. On average, Grand Isle has been affected by tropical storms or hurricanes every 2.68 years (since 1877), with direct hits on average every 7.88 years. Some of the more severe are listed here.
In 1860 a storm surge and great winds resulted in the total devastation of the island. In the 1893 Atlantic hurricane season Grand Isle was devastated by a storm surge. In the 1909 Atlantic hurricane season the island was hit with a second storm surge. A Category 4 hurricane devastated Grand Isle on 29 September during the 1915 Atlantic hurricane season. Grand Isle was hit by a storm surge on 22 August during the 1947 Atlantic hurricane season. In 1956 Hurricane Flossy damaged the island.
Hurricane Betsy in September 1965, then Tropical Storm Frances, put the entire island under water in 1998. On 26 September 2002, Grand Isle was hit by Tropical Storm Isidore soon followed by Hurricane Lili passing to the west of the isle, causing significant damage. Hurricane Cindy scored a direct hit on Grand Isle on July 5, 2005. Even though damage was essentially limited to power outages and beach erosion, the storm's strength still caught residents by surprise.
Hurricane Katrina pounded Grand Isle for two days, August 28–29, 2005, destroying or damaging homes and camps along the entire island. Katrina's surge reached at Grand Isle. Large waves severely damaged the only bridge linking Grand Isle to the mainland. A news report published less than two days after the hurricane hit falsely noted, however, that the area had been completely destroyed, reporting a scenario similar to that which befell Last Island in 1856. Less than a month later, Grand Isle was further affected by Hurricane Rita. By mid October, a number of businesses were again open on the island.
Hurricane Gustav reached shore west of the island on September 1, 2008, at 9 am CDT, and hit it with a measured wind speed of . It might be the only place in Louisiana hit when the storm was still classified as major hurricane. While both storms' eyes passed the island at similar distances, Katrina's eastern passing caused greatest damage on the bay side of island. The Gustav surge that swashed over the island damaged less than Katrina's, in part due to the most vulnerable structures having already been destroyed by Katrina. Current construction codes prevented the rebuilding of such vulnerable structures. Barataria pass water levels peaked at 5' above recent high tide. Homes along Highway 1 had of water below them. Large sections of levee/dunes were washed onto Highway 1.
Hurricane Ike passed far south of the island on September 11, 2008 while crews worked to restore power and repair the levee/dune damage caused by Gustav. Some sections of Highway 1 west of the island were covered by of water. Wind gusts reached and Barataria pass water levels reached 3 ft (1 m) above recent high tide while Ike was away.