Plaquemines Parish resident Angela Serpas reacts after seeing her flooded home for the first time following Hurricane Isaac, as her daughter Lainy takes pictures, in Braithwaite, Louisiana, on Saturday, September 1. At least five deaths in Louisiana and two in neighboring Mississippi were blamed on Isaac, and residents of the two states still suffered from power outages and widespread flooding on Saturday, authorities said. 
The Walker family leaves their home after an abandoned house next door collapsed onto theirs during Tropical Storm Isaac on Friday, August 31. The Red Cross was assisting the family in finding a place to stay. 
Cattle are stuck in a mixture of mud and debris washed in by Isaac's storm surge. Officials are attempting to conduct a roundup in Plaquemines to save about 200 cattle stranded by the storm. 
Local residents serve up chicken etouffee and rice delivered by the Louisiana National Guard at JJ's Bar in the Bywater neighborhood of New Orleans. The military gave out the food to residents of the area, which was still without electricity three days after Hurricane Isaac knocked out power to hundreds of thousands of people. 
Local residents drink by candlelight at JJ's bar during the continued blackout. 
Oil containers and railroad cars sit in Isaac's flood waters in Braithwaite, Louisiana. 
Republican presidential candidate Mitt Romney talks with a man on the side of the road while on an unscheduled tour of a neighorhood damaged by Isaac on Friday, August 31, in Lafitte, Louisiana. 
A family carries bags of ice and boxes of food from an aid distribution center for victims of Isaac in New Orleans. The center was one of three in the city operated by the military, offering handouts to residents, many of whom still have no electricity due to the storm. 
Residents look out from their residence surrounded by water as the motorcade of Romney passes during a tour of damage from Isaac in Lafitte. 
Flood waters from Tropical Storm Isaac swamp homes in Braithwaite, Louisiana, on Friday, August 31, 2012. 
Vivian Lane, 5, helps her mother, Ashley Lane, make rice and gravy on their porch after Hurricane Isaac knocked out their power in Bay Saint Louis, Mississippi, Friday. 
Tombstones washed from their resting place by flood waters from a levee breach in Braithwaite, Louisiana, on Friday. 
The ship Arosa Basel sits grounded on the east bank of the Mississippi River in Plaquemines Parish, Louisiana, Friday. 
Dead nutria lie on the shore near Waveland, Mississippi, on Friday. 
A truck, partially submerged by a levee breach, gives off a sheen of oil and fuel in Braithwaite, Louisiana, on Friday. 
Members of the Louisiana Army National Guard and Louisiana Air National Guard distribute water, MREs and ice at Skelly-Rupp Stadium in New Orleans on Friday. 
Jewel Rico and her dog Chico are rescued from flood waters from Isaac on Thursday, August 30, in Reserve, Louisiana. 
Darrell Hill, 11, feeds his sister Floy Dillon, 2, at a flood shelter set up in a high school gym. 
People get off a Slidell Police Department SWAT vehicle after being rescued from flooding from Isaac's storm surge on the north shore of Lake Pontchartrain. 
Residents sit on a bus Thursday after evacuating Laplace, Louisiana. 
A heavy band of storms hovers ominously over New Orleans in the aftermath of Isaac on Thursday. 
Two men paddle a boat with street signs in flood waters from Hurricane Isaac in Reserve, Louisiana. 
Subdivisions in LaPlace, west of U.S. 51 and south of Interstate-10 are covered in floodwaters in the aftermath of Isaac. 
The Lake Borgne Basin Levee District and other government agencies intentionally breached the Caernarvon Diversion to help drain flood waters in Plaquemines Parish, Louisiana. 
A woman is stranded with her truck in floodwaters from Isaac on the north shore of Lake Pontchartrain on Thursday in Slidell, Louisiana. 
Brittany Trumbaturi, right, prepares to leave her flooded home with family member Joshua Barbot, center, who came to rescue family members in a boat. Officials warned of continued threats from storm surges and flooding as Isaac moved inland. 
Jamaal Nelson carries his son, Jon-Wesley, 6, on his back and his 4-month-old baby daughter, Jalashia, while being evacuated from their flooded neighborhood in Slidell. 
Residents stand in front of their home as flooded streets engulf their neighborhood in Slidell. 
Elderly residents evacuate to a shelter in Slidell 
A resident evacuates an area flooded by Hurricane Isaac's storm surge on the north shore of Lake Pontchartrain. 
Residents evacuate their flooded neighborhood. 
A man drives an off-road vehicle through flooded streets in Slidell. 
Residents carry pillows, blankets and fuel containers past a flood berm while evacuating an area of rising floodwaters on Thursday in Slidell. 
An elderly resident is rescued from her home in Slidell. 
Residents run down a road in Slidell clutching their belongings as they evacuate an area of rising floodwaters from Isaac's rains. 
Rescue workers transport residents trapped by rising water from Isaac in Laplace, Louisiana, on Wednesday. 
Water surrounds a home on the Jourdan River in Kiln, Mississippi, as Isaac moves through the area. 
Residents are rescued Wednesday in Laplace, about 25 miles northwest of New Orleans, where the storm surge was unusually bad. 
Henry Cox talks with stranded residents in Laplace. 
Errol Ragas walks past a cemetery to recover dry blankets from his home as rising waters flood in Oakville, Louisiana. Plaquemines Parish, south of New Orleans, was the area most heavily damaged by the hurricane. 
Storm-weary residents take refuge at a high school gymnasium in Belle Chasse, a low-lying area outside of New Orleans. 
St. John Parish Sherriff officials rescue local residents from the flood waters in Laplace. 
Lisa, Christopher and Leroy Smith sit in a boat after being pulled from the flood waters. 
A stop sign stands askew in New Orleans after being blown by Isaac. 
People gather at a bar in the French Quarter during ongoing rain from Isaac. The area appeared largely unscathed by the storm. 
A house in New Orleans collapsed during the height of Hurricane Isaac, destroying three vehicles parked alongside it Wednesday. 
Waves from Hurricane Isaac pummel Ken Combs Pier in Gulfport, Mississippi. 
A street sign turned upside down, likely the result of bricks falling overnight from a building along the deserted streets of New Orleans. 
A car sits submerged in Laplace, Louisiana. 
People gather beneath an awning for an impromptu cookout at a bar that lost electricity during Hurricane Isaac in New Orleans. 
Emergency crews and residents rescue a dog during Hurricane Isaac on Highway 39 separating Plaquemines and St. Bernard parishes on Wednesday, August 29, in Louisiana. 
First responders carry people across the top of the levee from Plaquemines Parish to St. Bernard Parish. 
Mark Savoie cleans Espanade Avenue in New Orleans of tree debris to help the area near Burgundy drain as Isaac slowly moves inland. 
A worker in the driving rain tries to clear fallen limbs in the riverbound lanes of Espanade Avenue near McDonogh High School in New Orleans. 
Winds from Isaac knocked down tree branches in Kenner, Louisiana. 
A child and an adult share a folding bed as storm-weary residents take refuge at a high school gymnasium in Belle Chasse, in low-lying Plaquemines Parish, outside of New Orleans. 
A tree toppled by Isaac stretches across the roof of a food stand in Arabi, Louisiana. 
A tree blown over from Hurricane Isaac lies atop a cemetery tomb in Plaquemines Parish. 
A street sign lies near floodwaters fromIsaac on Wednesday, in Braithwaite, Louisiana. Dozens were reportedly rescued in the area after levees were overtopped by floodwaters from Hurricane Isaac. 
A rescue boat passes a partially submerged stop sign. 
A car drives down Canal Street on Wednesday. The storm is slowly moving across southeast Louisiana, dumping large amounts of rain and knocking out power in scattered parts of the state. 
A traffic light continues to glow after being downed by Isaac's winds. 
A fallen tree blocks a road in New Orleans as Isaac batters the city and surrounding region, flooding homes and driving stormy waters over the top of at least one levee. 
Dozens were reportedly rescued in Plaquemines Parish after levees were overtopped by floodwaters. 
John Stone of Bay St. Louis, Mississippi, and his dog are led out of the water by a member of the Swift Water Rescue Team after being rescued from his flooded house. 
A tree was pushed over outside Tulane Medical Center in New Orleans. 
People rest in a rescue truck atop a levee in Plaquemines Parish. 
Rescue workers survey the floodwaters from a levee in Braithwaite. 
Police officers stand watch in the French Quarter. 
Isaac pounds Gulf CoastA traffic light dangles at an intersection in Metairie, Louisiana, during strong wind and rain as Hurricane Isaac pushes ashore. 
A tree toppled by hurricane-force winds lies on power lines near a home in New Orleans. 
A storm surge causes water to quickly rise while waves pound the concrete seawall along the shores of Lake Pontchartrain in New Orleans on Tuesday, August 28. 
Scott Burley runs from crashing surf on the Ken Combs Pier in Gulfport, Mississippi. 
Jason Preston closes shutters on a home in Gulfport, Mississippi, as Hurricane Isaac approaches. 
Emily Schneider leans against a pole to support herself against strong winds while visiting the banks of Lake Pontchartrain in New Orleans, where Hurricane Isaac has made landfall. 
Water rises from a bayou, flooding properties ahead of the arrival of Hurricane Isaac in Bay St. Louis, Mississippi. 
Bridgette Mooney, her husband Kevin, and their 15-month-old daughter Skyler watch from their home as Hurricane Isaac lashes their property with rain in Kiln, Mississippi. 
Employees of the Orleans Levee District remove signs from Lake Shore Drive near the shore of Lake Pontchartrain. 
Evan Stoudt faces strong winds from the banks of Lake Pontchartrain. 
A man walks on Canal Street in New Orleans. 
Joshua Keegan and Ruffin Henry swim at Lake Pontchartrain. 
High surf splashes along Highway 193 north of the Dauphin Island Bridge in Alabama. 
Waves from Hurricane Isaac smash against a warning sign at a flooded beach in Biloxi, Mississippi. 
A group of men sit on a bench at the edge of Lake Pontchartrain as Hurricane Isaac approaches. 
Matthew Pettus holds a sheet open in the wind on the levee near Lake Pontchartrain. 
People make their way across Canal Street in New Orleans. 
Joshua Keegan and his dog Scout swim in the rising water of Lake Pontchartrain. 
A Mississippi Department of Transportation sign in Hattiesburg warns southbound motorists on U.S. 49 of rough weather conditions on Tuesday, August 28. Hurricane Isaac is expected to drop heavy rain on the Mississippi Coast over the next couple of days. 
A woman and her dog watch the waves produced by Hurricane Isaac on the shore of Lake Pontchatrain in New Orleans on Tuesday. Hurricane Isaac is expected to make landfall later tonight along the Louisiana coast. 
Louisiana Gov. Bobby Jindal and New Orleans Mayor Mitch Landrieu receive an update on the status of the pumping station at the 17th Street Canal in Metairie, Louisiana. 
A couple takes photos in Bay St. Louis, Mississippi. Many residents of the area decided to stay in their homes instead of evacuating. 
A man skateboards past a bar with boarded windows in the French Quarter in New Orleans. 
Diana Whipple of New Orleans watches waves crash on the shore of Lake Pontchartrain as Hurricane Isaac approaches Tuesday. Isaac became a Category 1 hurricane Tuesday when its maximum sustained winds reached 75 mph, the National Hurricane Center says. 
Workers try to close off state Highway 23 South in Oakville, Louisiana, on Tueday as Issac heads toward the coast. 
Gallery Nine Forty in New Orleans' French Quarter notifies customers it's "on Hurrication." 
Workers board up a business on Bourbon Street in the French Quarter as Isaac approaches Tuesday. 
Hydraulic pumps are prepared at the 17th Street Canal floodwall Tuesday in New Orleans. 
A woman enjoys the a heavy rain in the Tampa, Florida, area, on Monday. Hurricane Isaac is expected to make landfall near New Orleans. 
Mounted law enforcement officials wait out a brief rainstorm during the National Republican Convention. Commercial bus cancellations caused by Isaac prevented many of the expected demonstrators from being present. 
A sign in the French Quarter makes fun of Hurricane Isaac. 
Workers place plywood on the windows of the Royal Sonesta Hotel on Bourbon Street. 
Aimo Ny rests on her cot in the hurricane shelter at the Belle Chasse Auditorium on Monday in Belle Chasse, Louisiana. 
iReporter Liz Yavinsky snapped this picture of a boy floating down a flooded street in West Palm Beach, Florida, on Monday. 
The manager of a shoe store in Harvey, Louisiana, places plywood over the windows in preparation of Hurricane Isaac. 
A crew from Jefferson Parish Drainage Department places large sandbags near a canal and pond in Jean Lafitte, Louisiana, on Monday in preparation for Isaac. 
A St. Petersburg, Florida, resident walks along the sea wall at Spa Beach, where larger than average waves were being kicked up by Tropical Storm Isaac on Monday. 
Oliver Marti sweeps water from heavy rains generated by Tropical Storm Isaac off the roof of his flower shop on Monday in Tampa, Florida. 
Waves batter the coast in Havana, Cuba, on Sunday after Tropical Storm Isaac passed the island. 
Larry Hoffmeister, left, and Charles Carter place storm shutters on Carter's vacation home on Dauphin Island, Alabama, as they prepare for Isaac on Sunday. 
Justin and Kayla Franklin of Tennessee walk in wind and rain in downtown Key West as Tropical Storm Isaac moves over the island. 
Biloxi, Mississippi, resident Stephanie Dale fills out paperwork Sunday to have her dog microchipped at the Humane Society of South Mississippi, which opened its doors to provide an emergency microchip and tag clinic. 
Ocean Springs, Mississippi, resident Charles Bartlett fills several gas containers in preparation for Isaac. 
Andrew Marino, left, and Colby Collier pull a wagon filled with sandbags back to their homes as Florida residents prepared for Tropical Storm Isaac in St. Pete Beach, Florida, on Sunday. 
Palm trees blow in the wind in front of the Tampa Bay Times Forum, where the start of the Republican National Convention was pushed to Tuesday. 
Earl, right, and Terri Harris place sandbags around their home to prepare for possible flooding. 
A couple watch as waves and strong winds from Tropical Storm Isaac, which crossed Cuba on Sunday, batter the shore in Gibara, Cuba, on Saturday. 
Strong winds bend palm trees in Cuba's northern province of Sancti Spiritus on Saturday. Isaac is expected to strengthen and become a Category 1 hurricane by early Monday as it draws nearer to Florida. 
A man captures the effects of Tropical Storm Isaac in Gibara. 
People watch from the shore as waves pound the coast in Gibara. 
Officials reported some storm surge and flooding in eastern Cuba. 
Tampa, Florida, area residents make preparations for the arrival of Tropical Storm Isaac by filling sandbags at a Hillsborough County Public Works Service Center on Saturday. 
A woman sits atop sandbags filled by Tampa area residents in preparation for the storm. 
Two men install storm shutters on Duval Street on Saturday. 
Vehicles cross a bridge leaving the Lower Keys on Saturday as the storm strengthens and moves closer. 
- Mandatory evacuations are in place in St. Tammany Parish, north of New Orleans
- A canal lock is in danger of failing, officials say
- The Pearl River, swollen by rain, is also threatening to flood area homes, officials say
- Flash flood warnings are issued for portions of Tennessee and Kentucky, forecasters say
(CNN) -- As the remnants of Isaac threatened flash flooding in portions of Tennessee and Kentucky on Sunday, residents in Louisiana and Mississippi grappled with the aftermath of the storm that again brought mandatory evacuations amid flood warnings.
Mandatory evacuations were issued Saturday night for portions of Louisiana's St. Tammany Parish after the Pearl River swollen by days of rain threatened to overwhelm a lock in one area and overflow its banks in another, potentially flooding hundreds of homes.
The most pressing issue was the potential failure of a lock on a man-made canal that juts off the Pearl River.
After getting permission from the U.S. Army Corps of Engineers, authorities on Saturday "opened some valves" to prevent the lock from failing, St. Tammany Parish spokeswoman Suzanne Stymiest said.
"We are beginning to relieve some of the pressure, and we are hopeful," Stymiest said. "However, the mandatory evacuation is still in place. We cannot determine (yet) that we have been successful."
People living in the parish, which sits on the north shore of Lake Ponchartrain between the towns of Bush and Hickory, will not be allowed to return until the structural integrity of the lock is assured, parish officials said.
Missouri drought farmers eye Isaac 
Labor Day weekend forecast 
Hurricane Isaac's wrath Meanwhile, the parish was also contending with another potential flooding problem. The Pearl River, which flows from Mississippi into Louisiana, crested Monday at 19.5 feet, according to a special notice posted Saturday night on the St. Tammany Parish website.
"We have a plan in place and will provide you with any and all information as this situation progresses," the notice said.
At least 35 subdivisions, four mobile home parks and one campsite were alerted to possible flooding, though authorities did not immediately call for evacuations.
The remnants of Isaac, meanwhile, moved to the northeast early Sunday, after scattering much needed rain on parts of the drought-ridden lower Midwest. Missouri and Illinois both saw up to six inches of rain in some areas on Saturday.
The National Weather Service issued a flash flood warning early Sunday for portions of Kentucky and Tennessee as well as the Central Appalachian Mountain region.
Isaac is blamed for at least 19 deaths in Haiti and at least four more in Louisiana and Mississippi after making landfall last week as a Category 1 hurricane -- on the seventh anniversary of Hurricane Katrina -- near the mouth of the Mississippi River.
The storm posed the first real test to New Orleans following a $14.5 billion federal effort to reconstruct the city's flood control system after it failed during Katrina in 2005. Katrina killed nearly 1,800 people, most when the storm overwhelmed the levee system and flooded the city.
Though much weaker than Katrina when it came ashore, Isaac moved slowly and dumped enormous amounts of rain on Louisiana and Missouri.
Louisiana's Plaquemines Paris was overwhelmed by Isaac, which caused a parish-maintained back levee to fail and contributed to the flooding of businesses and homes.
Officials were intentionally breaching levees in strategic areas in the parish, in hopes of getting "the bulk of this water out in five to seven days," Plaquemines Parish President Billy Nungesser said Saturday.
Hundreds of thousands in the region were without power early Sunday, including at least 320,000 Entergy Louisiana customers, officials said
Residents began returning home over the weekend in Helena, Mississippi, where National Guard troops rescued hundreds trapped by rising waters brought on by Isaac.
Annie Judge returned home Saturday to find more than four feet of water inside her home.
"Clothes, my laptop, a bunch of baby stuff, pictures," all ruined, she told CNN affiliate WLOX. "All the furniture is ruined."
CNN's David Ariosto contributed to this report.
