Through Sunday morning, Harvey continued to unleash record levels of rain on Houston, causing "catastrophic" flooding in the city and in surrounding Harris County. At least one storm-related death in Houston was reported on Sunday, after a woman was found dead by her water-deluged car.
Over 24 hours, the greater Houston and Galveston area received 24.1 inches of rain. The National Weather Service warned of "additional catastrophic, unprecedented and life threatening flooding" into the next week, and placed flash-flood emergencies for all of Southeast Texas.
As the much-anticipated storm pummeled the country's fourth-largest city — overwhelming the 911 system and sending some residents, against the advice of officials, into their attics to flee floodwaters — many asked the question: Should Houston have been evacuated? If so, why wasn't it?
At least one official thought it should have been.
At a Friday news conference, Texas Gov. Greg Abbott (R) encouraged residents in low-lying and coastal areas of the state to evacuate, even if a mandatory evacuation order had not been issued.
"Even if an evacuation order hasn't been issued by your local official, if you're in an area between Corpus Christi and Houston, you need to strongly consider evacuating," Abbott said. "What you don't know, and what nobody else knows right now, is the magnitude of flooding that will be coming.
"You don't want to put yourself in a situation where you could be subject to a search and rescue."
The governor's warning was in sharp contrast to the advice local and county officials had been dispensing for days: to shelter and stay in place. And it set off a scramble by local officials on social media to tell their residents otherwise.
"LOCAL LEADERS KNOW BEST," Francisco Sanchez, spokesman for the Harris County Office of Homeland Security and Emergency Management, tweeted in response to Abbott's warning. There were no evacuation orders in Houston, and only ones in a few communities in Harris County, Sanchez stressed.
In a follow-up tweet, Sanchez urged residents to heed the advice of local officials like Harris County Judge Ed Emmett and Houston Mayor Sylvester Turner, rather than Abbott.
On Saturday morning, as Hurricane Harvey's powerful winds and rain caused severe damage to coastal communities, the Houston mayor warned people there would be heavy rain and flooding in the city for the next four to five days — but once again emphasized they did not need to evacuate.
Turner also addressed concerns that Abbott and local officials had sent conflicting messages about what was safer: fleeing or staying in place.
"I think the governor and I both agree that this is a serious and unprecedented storm," Turner said Saturday on "Good Morning America." While everyone had agreed the Southeast Texas cities of Victoria and Rockport needed to be evacuated, as they were in the direct line of the hurricane, Houston and Harris County were different.
"For Houston, Harris County, the county judge and I both agreed that for us this was a major rainfall event and so there was no need to evacuate. We are asking people to stay off the streets," Turner said. "Quite frankly, leaving your homes, getting on the streets, you'll be putting yourself in more danger and not making yourself safer. And so, we're just asking people to hunker down."
However, reports and images from Houston and Harris County showed it was increasingly difficult for people to do so.
As The Washington Post's Greg Porter and Jason Samenow report, the situation is only getting worse:
"The Weather Service office in Houston reported 24.1 inches of rain in 24 hours as of 7 a.m. Sunday morning and said this August had become the wettest month in recorded history due to the storm.
"It added the 'majority' of rivers and bayous around Houston were at record levels and some were exceeding previous records by 10 feet.
"'Volume-wise, this has likely reached the rainfall that fell during Allison in June 2001, and it continues to rain,' said the Weather Service office in College Park, Maryland, responsible for rainfall forecasts.
"The National Weather Service Weather Prediction Center is calling for an additional 15-25 inches of rain over the middle and upper Texas coast, including the Houston area, during the next several days, with isolated amounts possibly reaching 40 inches."
"This disaster's going to be a landmark event," FEMA administrator Brock Long said on CNN's "State of the Union" Sunday. "This is a storm that the United States has not seen yet."
The dire reports didn't stop President Donald Trump from tweeting Sunday morning that the flood-response efforts were "going well":
"Wow - Now experts are calling #Harvey a once in 500 year flood! We have an all out effort going, and going well!"
Houston area officials who urged people to stay home before the storm may have been remembering that the city government was strongly criticized after the disastrous evacuation before Hurricane Rita in 2005.
In the hours before Rita struck the Houston area in September 2005, government officials issued an evacuation order, and some 2.5 million people hit the road at the same time, according to the Houston Chronicle.
More than 100 people died in the mass exit from the city - almost as many as were killed by the hurricane itself.
Dozens were injured or died of heat stroke waiting in traffic for nearly a full day. Fights broke out on clogged highways. A charter bus carrying people from a nursing home exploded on the side of Interstate 45, killing 24 people inside.
Meanwhile, the fear from Hurricane Rita turned out to be unfounded. It weakened from a Category 5 churning in the Gulf of Mexico to a Category 3 by the time it made landfall in East Texas - and resulted in a fraction of the damage and deaths as Hurricane Katrina, which had ravaged New Orleans three weeks earlier.
After Hurricane Rita, many in Houston returned to their homes after hours of languishing on the highway "and found the house was fine and the street wasn't flooded," according to Madhu Beriwal, the president and CEO of IEM, a disaster planning and prevention company who has worked in Harris County.
In evacuation planning, public officials are trying to find "the course of least regret," Beriwal said. Traveling by car has inherent risks, and any evacuation order comes with the grim understanding that people will die trying to get out, he added.
"We know that there's going to result in a certain number of deaths just by having so many people on the road," Beriwal told The Post. "When you have evacuation traffic, it's even more difficult, because you have people that are very vulnerable traveling. ... The people that tend to die in bigger numbers (during evacuations) are generally the elderly - people that wouldn't normally be on the road anyway."
But no matter which path officials decide to take, Beriwal said, "It is always better to speak with one voice so people know what the officials think is the best thing to do."
After Rita, officials began changing laws and government programs to improve future evacuations.
The state's emergency management division began to work more closely with municipalities to coordinate hurricane response plans, the Texas Tribune reported, "including finding ways to restore power sooner."
Lawmakers amended statutes to make it easier for emergency workers from other parts of the state to help during a crisis, the Tribune reported, and removed liability worries that hindered mutual aid.
And now, state and local authorities participate in drills to reverse the traffic flow on the highway to "ensure various agencies stay familiar with the process."