Heavy rains from Beta have shifted away from the Houston area after causing extensive flooding, but the storm on Tuesday is threatening to cause more damage in parts of Louisiana still recovering from Hurricane Laura.

Beta, which made landfall in Texas as a tropical storm before being downgraded to a tropical depression, is bringing heavy rainfall from eastern Texas across the lower Mississippi River Valley.

The National Weather Service (NWS) said that over 11 million Americans are under flash flood watches, as the storm could bring up to 15 inches of rain along the Texas coast and up to 5 inches of rain inland.

LIVE UPDATES: BETA WEAKENS INTO A POST-TROPICAL CYCLONE, THREAT OF FLOODING REMAINS

"Significant urban flooding will continue as well as minor to isolated moderate river flooding," the National Hurricane Center (NHC) said Wednesday morning. "Flash flooding will remain possible through Wednesday afternoon."

Vehicles are stranded at the intersection of Pearland and South Sam Houston Parkways, Tuesday, Sept. 22, 2020, in Houston, following flooding from Tropical Storm Beta.

Vehicles are stranded at the intersection of Pearland and South Sam Houston Parkways, Tuesday, Sept. 22, 2020, in Houston, following flooding from Tropical Storm Beta. (Godofredo A. Vásquez/Houston Chronicle via AP)

In the nation's fourth-largest city, Beta caused extensive flooding on streets and freeways on Tuesday.

Forecasters said Beta brought new daily rainfall records to the city of Houston, which saw 3.58 inches and Houston-Hobby Airport, which saw over 7 inches of rain.

Cars turn around on southbound 288 because of a road blockage caused by Tropical Storm Beta flooding Tuesday, Sept. 22, 2020, in Houston.

Cars turn around on southbound 288 because of a road blockage caused by Tropical Storm Beta flooding Tuesday, Sept. 22, 2020, in Houston. (Marie D. De Jesús/Houston Chronicle via AP)

The Texas Department of Transportation said Tuesday night that 37 different locations were being impacted by high water. Water levels were beginning to recede in some locations by Wednesday morning.

Some roads remain flooded in Surfside Beach, Texas, after Tropical Storm Beta made landfall overnight, on Tuesday, Sept. 22, 2020.

Some roads remain flooded in Surfside Beach, Texas, after Tropical Storm Beta made landfall overnight, on Tuesday, Sept. 22, 2020. (Godofredo A. Vásquez/Houston Chronicle via AP)

Houston Fire Chief Samuel Peña said first responders had done nearly 100 water rescues on city roadways since Monday evening.

Harris County Judge Lina Hidalgo said there were preliminary reports of some home flooding along a creek south of Houston.

A Houston Police Water Rescue vehicle mobilizes by a stranded by flood car on Houston Ave., during Tropical Storm Beta, Tuesday, Sept. 22, 2020, in Houston.

A Houston Police Water Rescue vehicle mobilizes by a stranded by flood car on Houston Ave., during Tropical Storm Beta, Tuesday, Sept. 22, 2020, in Houston. (Marie D. De Jesus/Houston Chronicle via AP)

Both Hidalgo, the top elected official in Harris County, and Houston Mayor Sylvester Turner urged residents to stay home and off the roads. About 70 barricades had been placed throughout the city in high water areas.

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“Your sedan is not a submarine. Your minivan is not magical. So stay off the roads right now," Hidalgo said. “Your destination is not worth your life. It's not worth the life of the first responder that’s going to have to come and rescue you if you drive into high water and are stuck there."

Cars get stranded on high flood waters on Houston Ave. exit from Interstate 45 during Tropical Storm Beta Tuesday, Sept. 22, 2020, in Houston.

Cars get stranded on high flood waters on Houston Ave. exit from Interstate 45 during Tropical Storm Beta Tuesday, Sept. 22, 2020, in Houston. (Marie D. De Jesus/Houston Chronicle via AP)

In Friendswood, Texas, south of Houston, officials warned residents in the 100-year flood plain to be prepared to evacuate the area if necessary after the Clear Creek rose 2 to 4 feet past its banks.

A home on Kingsmill Road has water up to its windows after the Clear Creek overflowed as Tropical Storm Beta rained over the area Tuesday, Sept. 22, 2020, in Friendswood, Texas.

A home on Kingsmill Road has water up to its windows after the Clear Creek overflowed as Tropical Storm Beta rained over the area Tuesday, Sept. 22, 2020, in Friendswood, Texas. (Steve Gonzales/Houston Chronicle via AP)

“I’m nervous. I don’t want my house to flood. It never flooded and it didn’t flood during Harvey but you never know," Rosemary Kacsmarski told FOX26. "You never know where the rain is going to fall the hardest and who’s going to get hit this time."

Water levels were still rising on Wednesday morning in some neighborhoods.

City officials in Houston also said that more than 100,000 gallons of domestic wastewater spilled in five locations due to  "intense, sustained, rainfall of greater than 10 inches in the last 24 hours."

Officials told FOX26 that as of late Tuesday, the estimated volume of released wastewater at each of the locations is greater than 100,000 gallons.

The city said the water supply is unaffected, and a boil notice is not necessary

Cars stranded on high flood waters on Houston Ave. exit from Interstate 45 during Tropical Storm Beta Tuesday, Sept. 22, 2020, in Houston.

Cars stranded on high flood waters on Houston Ave. exit from Interstate 45 during Tropical Storm Beta Tuesday, Sept. 22, 2020, in Houston. (Marie D. De Jesus/Houston Chronicle via AP)

The Houston Police Department said a fisherman was reported missing in Brays Bayou after someone reported he "jumped into the water" just after 6 p.m.

HPD Commander Elizabeth Lorenzana told KTRK-TV it was unknown if the man jumped into the water or if he lost his footing and fell in.

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"It's very dangerous to go out into the bayou," Lorenzana said. "I recommend people not going to the bayou."

The man's body was recovered just before 10:30 p.m., KTRK reported.

Adelle Puma attempts to get her dog "Ridge" from swimming in the flood water over the submerged Mary Xing bridge at Marys Creek that leads into Clear Creek as Tropical Storm Beta rainfall trained over the area Tuesday, Sept. 22, 2020, in Friendswood.

Adelle Puma attempts to get her dog "Ridge" from swimming in the flood water over the submerged Mary Xing bridge at Marys Creek that leads into Clear Creek as Tropical Storm Beta rainfall trained over the area Tuesday, Sept. 22, 2020, in Friendswood. (Steve Gonzales/Houston Chronicle via AP)

Beta was the ninth named storm that made landfall in the continental U.S. this year. That tied a record set in 1916, according to Colorado State University hurricane researcher Phil Klotzbach.

Buffalo Bayou's water levels are high due to heavy rains from Tropical Storm Beta as it rolls past downtown Tuesday, Sept. 22, 2020 in Houston.

Buffalo Bayou's water levels are high due to heavy rains from Tropical Storm Beta as it rolls past downtown Tuesday, Sept. 22, 2020 in Houston. (Brett Coomer/Houston Chronicle via AP)

Beta was expected to move over Louisiana, Arkansas, and Mississippi later in the week, bringing the risk of flash flooding. Storm surge flooding from Beta was impacting coastal Louisiana on Tuesday.

The rainfall and storm surge prompted Louisiana Gov. John Bel Edwards to declare a state of emergency.

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The storm was already having impacts in Cameron Parish, where residents are still working to clean up the damage from Hurricane Laura.

"We definitely have some flooding in the low-lying southern parts of the parish," Sheriff Ron Johnson told the Daily Advertiser. "No houses or structures have flooded, but some roads are impassable. It’s affecting us as to how we get where."

Lance Lindsley stands in the flooded garage of his house on Appleblossom Lane in Friendswood, Texas on Tuesday, Sept. 22, 2020, following Tropical Storm Beta.

Lance Lindsley stands in the flooded garage of his house on Appleblossom Lane in Friendswood, Texas on Tuesday, Sept. 22, 2020, following Tropical Storm Beta. (Stuart Villanueva/The Galveston County Daily News via AP)

Johnson advised people with campers to evacuate and many did. The sheriff added that there weren't that many people to evacuate overall due to many having lost their homes in Laura.

The Associated Press contributed to this report.