Rain was falling so heavily when Chad White pulled up in his gold Ford F-250 pickup that his hazard lights were the only indication he was there.

Along with dozens of other people, White and his young son got stuck Sunday morning at an intersection on Interstate 610 headed south from downtown Houston.

The flashing lights of a police vehicle blinked ahead of him, blocking a body of water about the size of an Olympic swimming pool that rendered the small stretch of highway impassable.

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White was trying to get to Friendswood in southeast Harris County, where people were trapped in homes swamped by unprecedented flooding.

He had a boat and supplies, and a determination to help. It was a scene that played out across the Houston area Sunday, as residents using boats, rafts and anything else that floated turned into rescuers.

1 / 9Houston SWAT officer Daryl Hudeck carries Catherine Pham and her son 13-month-old son Aiden to safety after they were rescued via boat from the flooding on Interstate 610 south in Houston on Sunday. (Louis DeLuca/The Dallas Morning News) 2 / 9A tractor-trailer rig kicks up foam as it navigates through the flooding on Intersate 610 south. (Louis DeLuca/The Dallas Morning News) 3 / 9Chad White, center rear, and his son John, right rear, pilot their boat back to higher ground as residents of Meyerland are helped by their volunteer effort. (Louis DeLuca/The Dallas Morning News) 4 / 9Chad White gets an appreciative handshake after he and his son helped stranded residents of Meyerland make it to dry ground. (Louis DeLuca/The Dallas Morning News) 5 / 9Motorists stranded in the flooding on Interstate 610 south in Houston make their way to higher ground in the flood waters. (Louis DeLuca/The Dallas Morning News) 6 / 9A stranded motorist tightropes along a highway divider as flooding closed Interstate 610 south near the Post Oak exit in Houston. (Louis DeLuca/The Dallas Morning News) 7 / 9Meyerland resident Connor Childs, in orange life jacket, and his dog Lacey are rescued by a water rescue team along Interstate 610 south. (Louis DeLuca/The Dallas Morning News) 8 / 9Greg Mayfield gives Jack the dog a chance to rest as he and friends help rescue a family from their flooded home and bring them to higher ground on Interstate 610 south. (Louis DeLuca/The Dallas Morning News) 9 / 9Lacey the dog peers out from the safety of a car after being rescued from a flooded home in Meyerland near Interstate 610 sout. (Louis DeLuca/The Dallas Morning News)

White set out Sunday morning from his home in El Campo, about 75 miles west of Houston, long before Harris County Judge Ed Emmett put out a public plea asking boat owners to offer any assistance they could.

“We desperately need boats and high-water vehicles,” Emmett said at an afternoon briefing. “We can’t wait for assets to come from the outside.”

White already knew that.

As he watched morning news reports of the devastation, he decided to hitch his 20-foot, flat-bottomed boat to his pickup, fill it with life vests and gasoline, and set out toward Friendswood to “pay it forward,” he said.

This is what White encountered when he got stopped on I-610:

Uniformed men were trying to clear the way for rescue vehicles to pass through. People fleeing their flooded homes walked unsteadily along a highway divider like they were on a balance beam. A red car floated along in the current.

One distressed couple trudged through waist-high water, but almost turned back over fears that their dogs, still at home, would drown. Water spilled over into a parking lot just before the Braeswood Boulevard exit, where others were waving and asking for assistance. A man was waist-deep in water, trying to help a woman who couldn’t swim.

Within minutes, White’s pickup was backing up toward the water, where National Guardsmen and police worked quickly to unhitch it and fill it with supplies. Then it was off, disappearing under the overpass.

It returned a half-hour later with an elderly man, his two sons and a yellow Lab. They carried large gray trash bags stuffed with all they could carry from their home.

Back and forth went White and his boat. Each time, he returned with grateful passengers. A mother of three and two little dogs. A woman carrying her 13-month-old boy.

Katrina Lee lives in Meyerland, the community just off the highway where she was waiting out the storm with her family.

“It just started rising,” she said, describing the water that poured into her one-story home and reached a depth of about 3 feet. “I didn’t think we were going to be able to stay there for another day, since more rain was coming.”

They fled to a neighbor’s two-story home, where two families totaling seven people called 911 for help.

“They said there was a lot of people calling,” Lee recalled.

So they hunkered down, and waited. Then, a knock on the door. Rescue teams had arrived, and they got there faster than they would have without White’s boat.

“We’re so thankful for their bravery,” Lee said.

White said he wanted to help because people gave him a hand when he experienced a hard time earlier in his life.

“I just want to do my part,” he said.

Sunday seemed like the right opportunity, he said. “I’ve never seen anything like this before. This ain’t normal."