Rescue crews use boats to reach stranded drivers and families trapped in their homes.

The tail-end of Tropical Storm Imelda that flooded parts of Texas killed at least two people on Thursday, with rescue crews using boats to reach stranded drivers and families trapped in their homes.

By Thursday night, floodwaters had started receding in most of the Houston area, and officials planned to work well into the night to clear freeways of vehicles stalled and abandoned because of the flooding.

Officials in Harris County, which includes Houston, said there had been a combination of at least 1,700 high-water rescues and evacuations to get people to shelter as the duration and intensity of the rain caught many by surprise.

More than 900 flights were cancelled or delayed in Houston and there were the inevitable widespread travel disruptions across a good part of eastern Texas.

Imelda’s remnants led to the death of two men on Thursday. A 19-year-old man was electrocuted while trying to move his horse to safety during a lightning storm.

Another man drowned when he tried to drive a van through eight-foot-deep (2.4 metres) floodwaters near Bush Intercontinental Airport in Houston during the Thursday afternoon rush hour, Harris County Sheriff Ed Gonzalez said.

The Houston area faced downpours, leading forecasters to issue a flash flood emergency for Harris County. Forecasters predicted possible hourly rainfall of 75-125mm (three to five inches).

Houston recorded 234mm of rain in 24 hours up to 06:00GMT on Friday. A staggering 203mm fell in just six hours. The average for the entire month of September is 125mm.

Elsewhere, Beaumont, located 145km (90 miles) to the east of Houston, notched up 421mm of rain on Thursday.

Shelters were set up in southeast Texas to provide a haven for people displaced by the heavy rain and flooding linked to the remnants of Imelda.

A shelter opened on Thursday at City Hall in the town of China, located about 16km (10 miles) west of Beaumont. Organisers say about a dozen people were at the site on Thursday afternoon, a shelter that could hold about 50 people.

People bought supplies, food and water to the shelter in the community of about 1,200, as some residents whose homes also flooded in 2017 during Hurricane Harvey had to evacuate again.

China Mayor Butch Sanders says many people arriving on Thursday at the shelter also had to leave their homes during Harvey and “it’s bothering a lot of them”, he said, having to go through this again. “But there’s nothing you can do about it except rebuild and move on.”

The worst of the rain is now beginning to weaken as it creeps north. Texas will be largely dry by the end of Friday with the worst of any bad weather moving into Arkansas and Oklahoma.