Harvey, which hit the Texas coast over the weekend as a Category 4 hurricane, has dumped more than 30 inches of rain on Houston, leading to historic, catastrophic flooding in the nation's fourth-largest city. See photos.
Rescue boats fill a flooded street as flood victims are evacuated as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Houston.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Flood victims wait to unload from the back of a heavy duty truck after being evacuated from their homes as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Houston.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Demetres Fair holds a towel over his daughter Damouri Fair, 2, as they are rescued by boat by members of the Louisiana Department of Wildlife and Fisheries and the Houston Fire Department during flooding from Tropical Storm Harvey in Houston, Monday, Aug. 28, 2017.
(AP Photo/Gerald Herbert)
AP Photo/Gerald Herbert
Displaced South Houston residents Oralia Guerra and Diamond Robinson huddle together to stay warm underneath Red Cross blankets at the George Brown Convention Center in Houston on Monday, Aug. 28, 2017, in the wake of Tropical Storm Harvey. Floodwaters reached the rooflines of single-story homes Monday and people could be heard pleading for help from inside as Harvey poured rain on the Houston area for a fourth consecutive day after a chaotic weekend of rising water and rescues.
(Louis DeLuca/The Dallas Morning News via AP)
Louis DeLuca/The Dallas Morning News via AP
A man carries a girl after being evacuated from their home as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Houston.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Volunteer rescue boats enter a flooded subdivision looking to evacuate residents as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A family is evacuated from their home as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Evacuees are helped down Tidwell Road as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Houston.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Evacuees wade down Tidwell Rd. after being evacuated from their homes as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Houston.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A Coast Guard rescue team evacuates people from a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
Volunteer rescue boats enter a flooded subdivision looking to evacuate residents as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A flooded home is shown as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Rhonda Worthington talks on her cell phone with a 911 dispatcher as he gets out of her car after her vehicle become stalled in rising floodwaters from Tropical Storm Harvey in Houston, Texas, Monday, Aug. 28, 2017. Worthington said she thought the water was low enough to drive through before the vehicle started to float away.
(AP Photo/LM Otero)
AP Photo/LM Otero
Rhonda Worthington is lifted into a boat while on her cell phone with a 911 dispatcher after her car become stuck in rising floodwaters from Tropical Storm Harvey in Houston, Texas, Monday, Aug. 28, 2017.
(AP Photo/LM Otero)
AP Photo/LM Otero
Volunteers use their boat to help evacuate residents as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
An overhead view of the flooding in Houston, from Buffalo Bayou on Memorial Drive and Allen Parkway, as heavy rains continue falling from Tropical Storm Harvey, Monday, Aug. 28, 2017.
( Karen Warren/Houston Chronicle via AP)
Karen Warren/Houston Chronicle via AP
Flood victims are towed to safety by a jet ski as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
People evacuate a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
James Gentry, left, helps evacuate a neighbor as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Residents are evacuated as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A family is evacuated from their home as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Conception Casa, center, and his friend Jose Martinez, right, check on Rhonda Worthington after her car become stuck in rising floodwaters from Tropical Storm Harvey in Houston, Texas, Monday, Aug. 28, 2017. The two men were evacuating their home that had become flooded when they encountered Worthington’s car floating off the road.
(AP Photo/LM Otero)
AP Photo/LM Otero
Floodwaters from Tropical Storm Harvey surround homes Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Volunteer rescue boats make their way into a flooded subdivision to rescue stranded residents as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Evacuees wade down a flooded section of Interstate 610 as floodwaters from Tropical Storm Harvey rise Sunday, Aug. 27, 2017, in Houston. The remnants of Hurricane Harvey sent devastating floods pouring into Houston Sunday as rising water chased thousands of people to rooftops or higher ground.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
People push a stalled pickup through a flooded street in Houston, after Tropical Storm Harvey dumped heavy rains, Sunday, Aug. 27, 2017. The remnants of Harvey sent devastating floods pouring into Houston on Sunday as rising water chased thousands of people to rooftops or higher ground.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
Homes are seen inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
Homes are seen inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
People walk down a flooded street as they evacuate their homes after the area was inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
People walk down a flooded street as they evacuate their homes after the area was inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
People wait to be rescued from their flooded homes after the area was inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
People walk down a flooded street as they evacuate their homes after the area was inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
People walk down a flooded street as they evacuate their homes after the area was inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
Local apartment residents cross high water on North Braeswood Blvd to escape the flooding from Hurricane Harvey August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in areas of Texas over the next couple of days.
(Photo by Erich Schlegel/Getty Images)
Photo by Erich Schlegel/Getty Images
People wait to be rescued from their flooded homes after the area was inundated with flooding from Hurricane Harvey on August 28, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
After helping the driver of the submerged truck get to safety, a man floats on the freeway flooded by Tropical Storm Harvey on Sunday, Aug. 27, 2017, near downtown Houston.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
Flooding in the Nottingham Forest section of Houston, including a cemetery and surrounding areas.
(WTOP/Steve Dresner)
WTOP/Steve Dresner
Flooding in the Nottingham Forest section of Houston
(WTOP/Steve Dresner)
WTOP/Steve Dresner
Flooding in the Nottingham Forest section of Houston, including a cemetery and surrounding areas.
(WTOP/Steve Dresner)
WTOP/Steve Dresner
A stranded boat is towed as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
John and Cathy Cservek hold their dogs Lacy and Iggy while being rescued from their home as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Kenny Muzny helps direct a rescue boat to his neighbor’s home as floodwaters from Tropical Storm Harvey rise Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Joe Garcia carries his dog Heidi from his flooded home as he is rescued from rising floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A row of tractors are surrounded by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Spring, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
People evacuate a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
Alexendre Jorge evacuates Ethan Colman, 4, from a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
A Jeep drives through a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
People evacuate a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
A man walks to his home in a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
People evacuate a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
People evacuate a neighborhood inundated by floodwaters from Tropical Storm Harvey on Monday, Aug. 28, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
This image made from a video shows a view from U.S. Route 59 of flooding on West Bellfort Avenue in Houston, Sunday, Aug. 27, 2017. The remnants of Hurricane Harvey sent devastating floods pouring into Houston Sunday as rising water chased thousands of people to rooftops or higher ground.
(DroneBase via AP)
DroneBase via AP
Two kayakers try to beat the current pushing them down an overflowing Brays Bayou from Tropical Storm Harvey in Houston, Texas, Sunday, Aug. 27, 2017.
(Mark Mulligan/Houston Chronicle via AP)
Mark Mulligan/Houston Chronicle via AP
A man wades through floodwaters from Tropical Storm Harvey Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Moses Juarez, left, and Anselmo Padilla wade through floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Residents wade through floodwaters from Tropical Storm Harvey Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A truck pushes through floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A family evacuates their Meyerland home in Houston, Sunday, Aug. 27, 2017. Rescuers answered hundreds of calls for help Sunday as floodwaters from the remnants of Hurricane Harvey rose high enough to begin filling second-story homes, and authorities urged stranded families to seek refuge on their rooftops.
(Mark Mulligan/Houston Chronicle via AP)
Mark Mulligan/Houston Chronicle via AP
Residents wade through floodwaters from Tropical Storm Harvey Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Residents sit on a fence surrounded by floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A man wades through floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Floodwaters from Tropical Storm Harvey flow in the Buffalo Bayou in downtown Houston, Texas, Monday, Aug. 28, 2017.
(AP Photo/LM Otero)
AP Photo/LM Otero
Residents are rescued from their homes surrounded by floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Andrew White (L) helps a neighbor down a street after rescuing her from her home in his boat in the upscale River Oaks neighborhood after it was inundated with flooding from Hurricane Harvey on Aug. 27, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Scott Olson/Getty Images)
Photo by Scott Olson/Getty Images
Floodwaters from Tropical Storm Harvey overflow Buffalo Bayou in Houston, Texas, Monday, Aug. 28, 2017.
(AP Photo/LM Otero)
AP Photo/LM Otero
Floodwaters from Tropical Storm Harvey flow in the Buffalo Bayou in downtown Houston, Texas, Monday, Aug. 28, 2017.
(AP Photo/LM Otero)
AP Photo/LM Otero
A pedestrian crosses a street inundated by floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
A man and woman try to navigate through floodwaters from Tropical Storm Harvey Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
A resident walks down a flooded street in the upscale River Oaks neighborhood after it was inundated with water from Hurricane Harvey on Aug. 27, 2017 in Houston, Texas.
(Photo by Scott Olson/Getty Images)
Photo by Scott Olson/Getty Images
Residents are rescued from their homes surrounded by floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
People walk through floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
A truck is submerged on a freeway flooded by Tropical Storm Harvey on Sunday, Aug. 27, 2017, near downtown Houston. The remnants of Hurricane Harvey sent devastating floods pouring into Houston Sunday as rising water chased thousands of people to rooftops or higher ground.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
A man takes photos of a freeway flooded by Tropical Storm Harvey on Sunday, Aug. 27, 2017, near downtown Houston, Texas.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
Flooding on Interstate 10 closed the major roadway to downtown Houston. Note, you can see someone on the flooded highway floating in a tube like taking a ride along a “lazy river” at a theme park.
(WTOP/Steve Dresner)
WTOP/Steve Dresner
Two people walk down a flooded section of Interstate 610 in floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Julius Verret, 14, floats in street flooding in Lake Charles, La., as the city is receiving heavy rains from Tropical Storm Harvey, Sunday, Aug. 27, 2017. The storm came ashore on the Texas Gulf Coast as a category four hurricane.
(AP Photo/Gerald Herbert)
AP Photo/Gerald Herbert
A car is submerged on a freeway flooded by Tropical Storm Harvey on Sunday, Aug. 27, 2017, near downtown Houston, Texas. The remnants of Hurricane Harvey sent devastating floods pouring into Houston on Sunday as rising water chased thousands of people to rooftops or higher ground.
(AP Photo/Charlie Riedel)
AP Photo/Charlie Riedel
A man helps a woman in floodwaters from Tropical Storm Harvey Sunday, Aug. 27, 2017, in Houston, Texas. The remnants of Hurricane Harvey sent devastating floods pouring into Houston Sunday as rising water chased thousands of people to rooftops or higher ground.
(AP Photo/David J. Phillip)
AP Photo/David J. Phillip
Naomi Coto carries Simba on her shoulders as they evacuate their home after the area was inundated with flooding from Hurricane Harvey on August 27, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in Texas over the next couple of days.
(Photo by Joe Raedle/Getty Images)
Photo by Joe Raedle/Getty Images
WASHINGTON — Harvey, which hit the Texas coast over the weekend as a Category 4 hurricane, has dumped more than 40 inches of rain on Houston, leading to historic, catastrophic flooding in the nation’s fourth-largest city.
The raging floodwaters turned streets into rivers navigable only by boat, submerged entire neighborhoods and trapped people on the roofs of their homes.
And more rain is still expected, authorities said.