NEW ORLEANS (AP) — As the remnants of Hurricane Isaac pushed their way up the Mississippi valley on Saturday, spinning off severe thunderstorms and at least four tornadoes, some on the Gulf Coast were impatient with the pace of restoring power days after the storm dragged through the region.

While New Orleans streets were bustling again and workers were returning to offshore oil rigs, thousands of evacuees couldn't return home to flooded low-lying areas of Louisiana and more than 400,000 sweltering electricity customers in the state remained without power.

Meanwhile, the National Weather Service said two tornadoes touched down in rural areas of north-central Illinois and at least two touched down in rural southeast Missouri. There were no reports of damage in Illinois, and Missouri officials said some power lines caught on fire.

The weather service said the storm would bring some drought relief to parts of the Mississippi and Ohio River Valleys. By midday Saturday, it had dumped up to 5 inches of rain in parts of Illinois and between 4 and 6 inches in parts of Missouri.

In Louisiana, the number without power was down from more than 900,000. However, in heavily populated Jefferson Parish near New Orleans, parish president John Young said Entergy Corp. was too slow in restoring electricity.

"I don't see boots on the ground," said Young, who complained that he has seen repair trucks sitting idle in a staging area and fielded calls from residents and business owners complaining about a lack of progress.

"We've restored about 45 percent of our customers in about a day and a half, Entergy spokesman Chanel Lagarde said Saturday. He added that crews have come in from 24 states. "In many situations, crews have driven all day and have worked their 16-hour day and have to rest for the day."

As of Saturday night, the company was reporting about 270,000 outages, most in Jefferson and Orleans parishes.

New Orleans Mayor Mitch Landrieu said he too was eager to get power back on. "Like everybody else, my patience is wearing thin," he said.

On Saturday afternoon, St. Tammany Parish officials ordered a mandatory evacuation of areas south of the Pearl River diversion canal, for fear a lock on a canal will fail. Parish authorities said the order could affect anywhere from several hundred to 2,000 residents in the rural area north of Slidell, which is across Lake Pontchartrain from New Orleans.

The U.S. Army Corps of Engineers operates the lock. Parish spokeswoman Suzanne Parsons Stymiest said the parish got permission from the corps to relieve pressure on the structure by opening a valve that will allow a controlled flow of water through it.

Parts of coastal Plaquemines Parish, where thousands were evacuated, remained under water. The National Weather Service has said Isaac dumped anywhere from 10 to 20 inches of rain on south Louisiana and south Mississippi.

In the water-logged town of Lafitte, Mayor Tim Kerner was allowing property owners and residents to return and begin cleaning up.

Meanwhile, Gulf of Mexico oil platforms were being repopulated after Isaac forced shutdown of most Gulf oil production.

People stuck inside stuffy, powerless homes were comparatively lucky. The Louisiana governor's office said more than 4,000 were in state, local or Red Cross shelters as of Saturday morning and that doesn't count others who took refuge with friends, family or in hotels.

LaPlace resident Roshonda Girrad was staying in a state-run shelter in Alexandria, 200 miles from her home. She was waiting for the chest-deep waters in her neighborhood to recede.

"The showers are horrible. The food is horrible," Girrad said. "I'm not from around here. I don't know what's going on. We're in the dark."

Isaac dumped as much as 16 inches of rain in some spots, and about 500 people had to be rescued by boat or high-water vehicles.

In New Orleans, most of the downtown area and the French Quarter had power again Saturday. The annual Southern Decadence festival, a celebration of gay culture, was underway. And the Superdome, which sustained minor damage, hosted a Saturday night football game between Tulane and Rutgers.

Republican presidential nominee Mitt Romney visited flood-ravaged communities on Friday, and President Barack Obama said he would arrive Monday — appearances this part of the country is all too familiar with after Hurricane Katrina in 2005 and the 2010 Gulf oil spill.

To the east, officials pumped and released water from a reservoir, easing the pressure behind an Isaac-stressed dam in Mississippi on the Louisiana border. The threat for the earthen dam on Lake Tangipahoa prompted evacuations in small towns and rural areas. Authorities later said they were allowing residents to return to their homes in those areas where the flood waters have since receded.

Crews intentionally breached a levee that was strained by Isaac's floodwaters in southeast Louisiana's Plaquemines Parish, which is outside the federal levee system. Parish President Billy Nungesser said the work was slow-going.

___

Associated Press writers Vicki Smith, Stacey Plaisance, Cain Burdeau and Janet McConnaughey in New Orleans; Heather Hollingsworth in Kansas City, Mo., and Jason Keyser in Chicago contributed to this story.

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  • People rescue cows from floodwaters after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Angela Serpas, Lainy Serpas

    Angela Serpas cries as she sees her flooded home for the first time since Hurricane Isaac pushed a 10-foot storm surge into Braithwaite, La., Saturday, Sept. 1, 2012. At right is her daughter Lainy Serpas, 11. While New Orleans streets were bustling again and workers were returning to offshore oil rigs, thousands of evacuees couldn't return home to flooded low-lying areas of Louisiana and more than 400,000 sweltering electricity customers in the state remained without power. (AP Photo/Gerald Herbert)

  • A tree falls against a home after Hurricane Isaac passed the area in Braithwaite, La., Saturday, Sept. 1, 2012. While New Orleans streets were bustling again and workers were returning to offshore oil rigs, thousands of evacuees couldn't return home to flooded low-lying areas of Louisiana and more than 400,000 sweltering electricity customers in the state remained without power. (AP Photo/Gerald Herbert)

  • US-VOTE-REPUBLICANS-ROMNEY-WEATHER

    Storm-affected residents make their way out of their flooded neighborhood following Hurricane Isaac in Crown Point, off the road to LaFitte, outside of New Orleans, on August 31, 2012 in Louisiana, where Republican White House hopeful Mitt Romney rushed to visit in a bid to burnish his presidential credentials ahead of his November battle with President Barack Obama. Coming off the back of a rousing Republican convention, Romney sought to build momentum by taking his new campaign plane to New Orleans, where rescue crews are clearing up after Hurricane Isaac unleashed a torrential downpour. AFP PHOTO / Frederic J. BROWN (Photo credit should read FREDERIC J. BROWN/AFP/GettyImages)

  • US Gulf Coast Copes With Aftermath Of Hurricane Isaac

    PLAQUEMINES PARISH, LA - AUGUST 31: Cattle are stuck in a mixture of mud debris washed in by Hurricane Isaac's storm surge on August 31, 2012 in Plaquemines Parish, Louisiana. Officials are attempting to conduct a cattle roundup in Plaquemines in an attempt to save around 200 cattle stranded by the storm. (Photo by Mario Tama/Getty Images)

  • US Gulf Coast Copes With Aftermath Of Hurricane Isaac

    BRAITHWAITE, LA - AUGUST 31: Tombs dislodged by a levee breach from Hurricane Isaac's flood waters sit by a roadway amongst debris on August 31, 2012 in Braithwaite, Louisiana. Louisiana residents continue to cope with the aftermath of Hurricane Isaac with ongoing flooding, destroyed property and many still without electricity. (Photo by Mario Tama/Getty Images)

  • Peter Roccaforte

    Peter Roccaforte walks through floodwaters from Hurricane Isaac at his home in Reserve, La., as some of his clothing hangs out to dry Saturday, Sept. 1, 2012. Floodwaters cover many streets and power remains out in some areas. Louisiana's Public Service Commission said more than 443,000 customers remained without electricity around Louisiana on Saturday morning, days after Hurricane Isaac crept across the state. (AP Photo/David J. Phillip)

  • The exits off of I-10 in Slidell, La. are flooded in the aftermath of Isaac on Thursday, Aug. 30, 2012. Isaac hovered over Louisiana for a third day Thursday, shedding more than a foot of additional rain that forced authorities to hurriedly evacuate areas ahead of the storm and rescue hundreds of people who could not escape as the rapidly rising waters swallowed entire neighborhoods. (AP Photo/The Times-Picayune, Michael Democker) MAGS OUT; NO SALES; USA TODAY OUT

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    SLIDELL, LA - AUGUST 30: Residents travel through their neighborhood by jetski during flooding from Hurricane Isaac's storm surge on the north shore of Lake Pontchartrain on August 30, 2012 in Slidell, Louisiana. The large Category 1 hurricane had slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. The weather system has now been downgraded to a tropical storm but is still producing heavy rains and flooding as it moves north. (Photo by Mario Tama/Getty Images)

  • Anthony Segrave rides in his boat as he leaves his son's flooded home in the aftermath of Hurricane Isaac in Slidell, La., Friday, Aug. 31, 2012. Isaac is now a tropical depression and the center was on track to cross Arkansas on Friday and southern Missouri on Friday night, spreading rain as it goes. (AP Photo/David J. Phillip)

  • Homes in LaPlace, La., west of US 51 and south of I-10, are covered in floodwaters in the aftermath of Isaac on Thursday, Aug. 30, 2012. Isaac hovered over Louisiana for a third day Thursday, shedding more than a foot of additional rain that forced authorities to hurriedly evacuate areas ahead of the storm and rescue hundreds of people who could not escape as the rapidly rising waters swallowed entire neighborhoods. (AP Photo/The Times-Picayune, Michael Democker) MAGS OUT; NO SALES; USA TODAY OUT

  • An intentional levy breach that was created to alleviate trapped floodwater is seen in the community of Braithwaite, La., in the aftermath of Hurricane Isaac, Thursday, Aug. 30, 2012. (AP Photo/Gerald Herbert)

  • Tony Rodriguez, right, carries his baby daughter Nicole as they and his wife Jodi Clelland leave their flooded home in the aftermath of Hurricane Isaac in Slidell, La., Friday, Aug. 31, 2012. Isaac is now a tropical depression and the center was on track to cross Arkansas on Friday and southern Missouri on Friday night, spreading rain as it goes. (AP Photo/David J. Phillip)

  • The city of New Orleans lies under a heavy band of storms in the aftermath of Isaac on Thursday, Aug. 30, 2012. Isaac hovered over Louisiana for a third day Thursday, shedding more than a foot of additional rain that forced authorities to hurriedly evacuate areas ahead of the storm and rescue hundreds of people who could not escape as the rapidly rising waters swallowed entire neighborhoods. (AP Photo/The Times-Picayune, Michael Democker) MAGS OUT; NO SALES; USA TODAY OUT

  • Interstate 10 in LaPLace, La. at the approach of the Twelve Mile Bridge is underwater because of Hurricane Isaac Thursday, August 30, 2012. Isaac soaked Louisiana for yet another day and pushed more water into neighborhoods all around the city, flooding homes and forcing last-minute evacuations and rescues. New Orleans itself was spared, thanks in large part to a levee system built after Katrina. (AP Photo/The Times-Picayune, John McCusker) MAGS OUT; NO SALES; USA TODAY OUT

  • This aerial photo shows the pumping station at the 17th Street Canal, built after Hurricane Katrina breached the wall and flooded New Orleans, Thursday, Aug. 30, 2012. Isaac soaked Louisiana for yet another day and pushed more water into neighborhoods all around the city, flooding homes and forcing last-minute evacuations and rescues. New Orleans itself was spared, thanks in large part to a levee system built after Katrina. (AP Photo/Gerald Herbert)

  • A car sits submerged after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Buster stands behind sand bags as he stares at the flood waters around his home, Thursday, Aug. 30, 2012, in LaPlace, La. Isaac has caused major flooding in the region. (AP Photo/Eric Gay)

  • Lonney Sciortino

    Lonney Sciortino prepares to cut down a tree which fell on top of his tamale stand during Isaac in Arabi, La.,Thursday, Aug. 30, 2012. Isaac's maximum sustained winds had decreased to 45 mph and the National Hurricane Center said it was expected to become a tropical depression by Thursday night. The storm's center was on track to cross Arkansas on Friday and southern Missouri on Friday night, spreading rain as it goes. (AP Photo/David J. Phillip)

  • Homes are surrounded by flooded water after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • A submerged cow is stranded amid debris in floodwaters after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Isaac Fields, Victor Jones

    Isaac Fields, left, and Victor Jones use street signs to paddle a boat out of their flooded neighbor, Thursday, Aug. 30, 2012, in LaPlace, La. Isaac has caused major flooding in the region. (AP Photo/Eric Gay)

  • The St. Paul Missionary Baptist Church is seen flooded after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Flooded water surrounds homes after Isaac passed through the region, in Plaquemines Parish, La., Thursday, Aug. 30, 2012. Isaac staggered toward central Louisiana early Thursday, its weakening winds still potent enough to drive storm surge into portions of the coast and the River Parishes between New Orleans and Baton Rouge. (AP Photo/Gerald Herbert)

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    SLIDELL, LA - AUGUST 30: A resident evacuates from flooding from Hurricane Isaac's storm surge on the north shore of Lake Ponchartrain on August 30, 2012 in Slidell, Louisiana. The large Category 1 hurricane had slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. The weather system has now been downgraded to a tropical storm but is still producing heavy rains and flooding as it moves north. (Photo by Mario Tama/Getty Images)

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    LAPLACE, LA - AUGUST 30: A man heads to check on his house through flood water that came on shore from Lake Pontratrain during Hurricane Isaac near the Indigo Lakes subdivsion on August 30, 2012 in LaPlace, Louisiana.The large Category 1 hurricane had slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. The weather system has now been downgraded to a tropical storm but is still producing heavy rains and flooding as it moves north. (Photo by Chris Graythen/Getty Images)

  • Chuck Cropp, center, his son Piers, left, and wife Liz, right, wade through floodwaters from Hurricane Isaac Wednesday, Aug. 29, 2012, in New Orleans. As Isaac made landfall, it was expected to dump as much as 20 inches of rain in several parts of Louisiana. (AP Photo/David J. Phillip)

  • Homes are flooded as Hurricane Isaac hits Wednesday, Aug. 29, 2012, in Braithwaite, La. As Isaac made landfall, it was expected to dump as much as 20 inches of rain in several parts of Louisiana. (AP Photo/David J. Phillip)

  • Kneaka Griffin, Ra-Maaz Williams

    Kneaka Griffin, of Davant, La., holds Ra-Maaz Williams, 5 months, at an evacuation shelter after Isaac made landfall as a hurricane, in Belle Chasse, La., Wednesday, Aug. 29, 2012. (AP Photo/Gerald Herbert)

  • Law enforcement officers and first responders help a family to reach dry land after they were rescued from floodwaters caused by Isaac in Pearlington, Miss., Wednesday, Aug. 29, 2012, during a nonstop rain. A number of residents of the small community were trapped by the rising waters and had be rescued or waited until the low tide when waters receded so they could walk out. (AP Photo/Rogelio V. Solis)

  • The waters of the Mississippi Sound surround a traffic sign along Coden Belt Road, Wednesday, Aug. 29, 2012 in Coden, Ala. as Isaac makes landfall along the Gulf Coast. Isaac, downgraded to a tropical storm, has top sustained winds of 70 mph (112 kph), just below the hurricane threshold of 74 mph (119 kph). The storm is about 50 miles (80 kilometers) west-southwest of New Orleans, where it is bringing drenching rains and fierce winds. (AP Photo/Mobile Register, G.M. Andrews MAGS OUT

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    NEW ORLEANS, LA - AUGUST 29: A downed streetlight lies in the rain from Hurricane Isaac in the Central Business District on August 29, 2012 in New Orleans, Louisiana. The large Level 1 hurricane is slowly moving across southeast Louisiana, dumping large amounts of rain and knocking out power to Louisianans in scattered parts of the state. (Photo by Mario Tama/Getty Images)

  • Lights are reflected on Canal Street as a police officer patrolling the area passes a pedestrian as storm bands from Hurricane Isaac hit, Tuesday, Aug. 28, 2012, in New Orleans, Louisiana. Isaac, a massive storm spanning nearly 200 miles from its center, made landfall Tuesday evening near the mouth of the Mississippi River. (AP Photo/Eric Gay)

  • David Stefano

    Bay St. Louis, Miss., fireman David Stefano reacts as he and other first responders use an airboat to reach a house fire Tuesday, Aug. 28, 2012. Isaac's rainfall flooded a number of streets in this Bay St. Louis subdivision, preventing firemen from responding quickly to the fire that destroyed a house. (AP Photo/Holbrook Mohr)

  • Ronnie Willis

    Ronnie Willis makes his way across Canal Street through the wind and rain from Hurricane Isaac Wednesday, Aug. 29, 2012, in New Orleans. (AP Photo/David J. Phillip)

  • Hurricane Isaac Hits New Orleans, Gulf Coast

    NEW ORLEANS, LA - AUGUST 29: Heavy rain from Hurricane Isaac obsures the view of the Crescent City Connection Bridge over the Mississiippi River early on August 29, 2012 in New Orleans, Louisiana. The large Level 1 hurricane slowly moved across southeast Louisiana, dumping huge amounts of rain and knocking out power to Louisianans in scattered parts of the state. (Photo by John Moore/Getty Images)

  • Timbers smolder after a fire gutted a house on stilts in a Bay St. Louis, Miss., neighborhood after rising storm waters from Isaac prevented firemen from responding quickly with their trucks Tuesday, Aug. 28, 2012. First responders used an airboat to reach the house in order to make sure the flames did not affect any neighboring homes. (AP Photo/Holbrook Mohr)

  • Waves tear apart a pier along the Mobile Bay near Dauphin Island on Tuesday, August 28, 2012. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • Bay St. Louis, Miss., first responders brave a driving rain storm as they use an airboat to reach a house fire in a flooded subdivision, Tuesday, Aug. 28, 2012. After several attempts to reach the house fire, flooded streets forced the fire fighters to use the airboat. (AP Photo/Holbrook Mohr)

  • A woman stands on a partially submerged picnic bench in the storm surge from Isaac, on Lakeshore Drive along Lake Pontchartrain, as the storm approaches landfall, in New Orleans, Tuesday, Aug. 28, 2012. (AP Photo/Gerald Herbert)

  • Waves tear apart a pier along Mobile Bay near Dauphin Island on Tuesday, August 28, 2012 in Coden, Ala. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • First responders seek the assistance of a City of Bay St. Louis, Miss., dump truck to tow their airboat back to their launch site after running aground Tuesday, Aug. 28, 2012. Isaac's rainfall flooded a number of streets in this Bay St. Louis, Miss., neighborhood preventing firemen from using their fire trucks. First responders used an airboat to reach a burning house in order to make sure the flames did not affect any neighboring homes. (AP Photo/Holbrook Mohr)

  • Alex, left, and Adam ,three-month-old Chihuahua puppies, play in their new kennel at the Houston SPCA on Tuesday, Aug. 28, 2012, in Houston. These two were among 70 cats and dogs that were evacuated from St. Bernard Parish Animal Control in anticipation of Hurricane Isaac. (AP Photo/Houston Chronicle, J. Patric Schneider)

  • Debris from crashing waves lies strewn over the parkway going to Dauphin Island forcing a closure to the island on Tuesday, August 28, 2012 in Coden, Ala. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • Debris lies strewn over the parkway going to Dauphin Island forcing a closure to the island on Tuesday, August 28, 2012 in Coden, Ala. Alabama took a glancing blow from Hurricane Isaac on Tuesday as it headed toward landfall in the northwestern Gulf of Mexico, but the storm still threatened the coast with high winds, torrential rain and pounding surf. (AP Photo/Butch Dill)

  • Dillard University students stay at the shelter in the gym of Centenary Colleges as they evacuated from New Orleans because of hurricane Isaac Tuesday afternoon, Aug. 28, 2012 in Shreveport, La. (AP Photo/The Times, Henrietta Wildsmith)

  • The Waterfront Seafood company is flooded as water covers Shell Belt Road in Bayou La Batre, Ala. on Tuesday, Aug. 28, 2012. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph. It could get stronger by the time it's expected to reach the swampy coast of southeast Louisiana. (AP Photo/Butch Dill)

  • Teresa Ragas, left, and her husband Bertrand Ragas, of Port Sulphur, La., lie side-by-side in cots at an evacuation shelter in Belle Chasse, La., due to the impending landfall of Isaac, which is expected reach the region as a hurricane this evening, Tuesday, Aug. 28, 2012. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph. (AP Photo/Gerald Herbert)

  • A concerned neighbor checks on a car as a storm surge from Isaac pushes into Panama City, Fla. on Tuesday, Aug. 28, 2012. (AP Photo/The News Herald/Panama City, Fla., Andrew Wardlow) MANDATORY CREDIT

  • Senior hurricane specialist Stacy Stewart updates Isaac to a category one hurricane at the National Hurricane Center in Miami, Tuesday, Aug. 28, 2012. Forecasters at the National Hurricane Center warned that Isaac, especially if it strikes at high tide, could cause storm surges of up to 12 feet (3.6 meters) along the coasts of southeast Louisiana and Mississippi and up to 6 feet (1.8 meters) as far away as the Florida Panhandle. (AP Photo/Alan Diaz)

  • Michelle Hice, Tommy Leonard

    Animal control officer Michelle Hice puts a temporary identification collar on "Snuggles,' as evacuee Tommy Leonard hands him over for safe keeping, at an evacuation shelter in Belle Chasse, La., due to the impending landfall of Isaac, which is expected reach the region as a hurricane this evening, Tuesday, Aug. 28, 2012. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph. (AP Photo/Gerald Herbert)