One child was killed over the weekend in Texas as flooding impacted large swaths of the state.

Two adults and a child were in a car in Johnson County, just south of Fort Worth, when they got caught in fast-moving water in the early morning hours on Sunday, officials said. The two adults who were in the car were rescued and taken to the hospital around 5 a.m. local time, but the young boy who was in the car was found dead about two hours later, Johnson County officials said.  

A flood watch had remained in effect for parts of southeastern Texas throughout Sunday, with forecasters expecting several more inches of rainfall and potentially serious runoff across a huge area that altogether covers more than 100 square miles and includes the city of Houston. The densely populated metro center is home to more than 2 million people and has been swamped by consistently heavy downpours. Crews carried out hundreds of water rescues in Houston and the surrounding neighborhoods earlier in the weekend. 

Flood watches are issued when a mixture of weather hazards creates favorable conditions for flooding, but they do not necessarily mean that flooding is imminent in a particular region. A flood watch was in effect from Harris County — which includes Houston all the way to College Station — through Sunday evening. It also extended eastward from greater Houston toward the Gulf Coast.

Flood watches for Brazos and Grimes Counties were extended through Monday night.

A Houston firetruck makes it way through flood water after severe flooding. / Credit: Houston Chronicle/Hearst Newspap © Provided by CBS News

Meteorologists warned people within the flood watch boundaries to prepare for additional spells of rainfall and thunderstorms overnight Saturday and throughout the day on Sunday, after previous rounds of heavy rain drenched the area and submerged a wide section of land in murky high waters. 

Crews had already rescued more than 400 people from homes, rooftops, and roadways by Saturday as neighborhoods flooded around Houston, the Associated Press reported, while others prepared to evacuate. Judge Lina Hidalgo, the top official in Harris County where Houston is located, said at the time that 178 people and 122 pets had been rescued in that jurisdiction alone. No deaths or injuries tied to the severe weather have been reported in Houston. 

More than 100 people had to be rescued in Haris Couty on Sunday as well, the county fire department said. 

A man waves at Texas Parks & Wildlife Department game wardens as they arrive by boat to rescue residents from floodwaters in Liberty County, Texas, on Saturday, May 4, 2024. / Credit: Lekan Oyekanmi / AP © Provided by CBS News

People still under flood watches in southeastern Texas were bracing for between 1 and 3 inches of additional rainfall on Sunday, although the National Weather Service said higher amounts — possibly as much as 8 inches — could end up happening in some places.

Ongoing flooding along the San Jacinto River was a main cause for concern as rain caused its water levels to rise past capacity. Houston Police shared a video on social media that showed an officer rescuing a man and three dogs who were trapped in 8 to 10 feet of floodwater on Saturday morning. That rescue happened in a trailer park along a section of the San Jacinto River near Lake Houston, police said.

"Excessive runoff has resulted in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations, particularly urban areas," the National Weather Service said in its latest advisory, noting that river flooding continued Sunday morning and ranged from moderate to major depending on the location. 

A severe weather outlook issued for the same region noted that localized flash flooding was also expected, "especially for areas that already received heavy rainfall over the last few days." With that, powerful and potentially damaging winds, large hail and tornadoes could also occur, according to the weather service. The heaviest rainfall was forecast in the morning.

Southeastern Texas has been hit hard by heavy rains over the last week, with Houston and neighborhoods in its vicinity feeling the brunt of the impacts. Hidalgo on Thursday announced that she had signed a disaster declaration for Harris County after the area got more rain than expected the previous night, putting communities near the San Jacinto River at particular risk, CBS affiliate KHOU reported. But storms have for days imperiled people living in river basins much farther inland, and the disaster declaration for Harris County came on the same day Texas Governor Greg Abbott expanded a broader disaster declaration to include 88 of the state's counties in total.