New Orleans — Rain bands from fast-moving Hurricane Nate lashed southeast Louisiana on Saturday afternoon as the storm headed for an evening landfall and residents in vulnerable, low-lying areas fled."It's coming," Larry Bertron said as he and his wife Kimberlee prepared to leave their home in the Braithwaite community of vulnerable Plaquemines Parish.Hurricane veterans, they lost one home in south Louisiana to Hurricane Katrina in 2005 and were preparing to leave the home they rebuilt after Hurricane Isaac in 2012. Many of the houses around theirs remain abandoned and blighted from Isaac.'I can't live on promises'"This will be it," said Bertron, who complained that local officials haven't done enough to improve area levees. "If it floods again, this will be it. I can't live on promises."Nate was located midday Saturday about 170 kilometres south of the mouth of the Mississippi River. It was still a Category 1 storm but was expected to reach Category 2 strength before making landfall. Nate killed at least 21 people after strafing Central America earlier in the week.States of emergency were declared in Louisiana, Mississippi and Alabama; officials announced evacuation orders in low-lying areas and the opening of shelters for anyone who needs them. New Orleans residents fretted over a city drainage system in which weaknesses were revealed during summer flash floods.Waterside sections of New Orleans, outside the city's levee system, were under an evacuation order. About 2 000 people were affected. But not everyone was complying.'I know it sounds insane'Gabriel Black of New Orleans' Venetian Isles community sent his wife, a friend, and three dogs to a hotel in the city. Black stayed behind because an 81-year-old neighbour refused to leave."I know it sounds insane, but he has bad legs and he doesn't have anybody who can get to him," Black said.Others nearby were staying as well. Nancy and Cleve Bell said their house is built so high off the ground that it stayed dry in the floods after Hurricane Katrina. Nancy Bell said they have a generator and plenty of supplies, and will be safe.Anticipation of Nate's high winds, rain and storm surge prompted evacuations in the barrier island town of Grand Isle and the coastal town of Lafitte.The vast majority of New Orleans residents were not under such an order. But a 19:00 curfew was declared for the city, whose fragile pumping and drainage system could face a major test once Nate strikes. System weaknesses - including the failure of some pumps and power-generating turbines - were exposed after an August 5 deluge flooded homes and businesses in some sections of the city.Stepping up effortsNew Orleans Mayor Mitch Landrieu said 109 of 120 pumps are functioning, which is 92% capacity. Some 26 backup generators were in place. Efforts to clean thousands of street catch basins have been stepped up, with vacuum trucks dispatched to various areas to suck out thick mud and debris.Landrieu also said flood-prone underpasses would be blocked Saturday to keep motorists from driving into standing water."Right now this storm should not bring us anything that we're not prepared to handle," Landrieu said Saturday.Forecaster said Nate could dump 7 to 15 centimetres of rain on the region — with isolated totals of up 25 centimetres.Louisiana Govenor John Bel Edwards said he spoke with President Trump on Saturday morning. "He assured me that LA would have all the assistance we need as we prepare for #Nate," the governor posted on Twitter.High tides?In Alabama, the Bankhead Tunnel - which passes under the Mobile River - was closed, with large doors and sandbags covering the entrances. On Dauphin Island — a barrier island south of Mobile — owners hauled boats out of the water. The major concern was the storm surge was projected to coincide with high tide. Shelters were being open for coastal residents.Mississippi Gov. Phil Bryant declared a state of emergency in six southernmost counties. State officials warned storm surge was the biggest danger in that state's low-lying coastal areas, as well as high winds that could damage mobile homes. The Mississippi Emergency Management Agency announced the opening of shelters on the coast Saturday. Crews were lowering high masts that hold street lights along the coast to keep the lights from becoming projectiles in high winds.The National Hurricane Center said a hurricane warning was in effect from Grand Isle, Louisiana, to the Alabama-Florida border and also for metropolitan New Orleans and nearby Lake Pontchartrain.Tropical storm warnings extended west of Grand Isle to Morgan City, Louisiana, and around Lake Maurepas and east of the Alabama-Florida border to the Okaloosa-Walton County line in the Florida Panhandle.