Walking the soggy streets of her League City neighborhood, Diane Alston said she was “heartbroken” that so many people waited out Harvey’s steady rains from inside their flooding homes, following instructions from local officials.

Alston, 23, looked like one of the lucky ones in this community about 25 miles southeast of Houston, even if she spent most of Friday night moving furniture in her two-story home to reduce the chances any of it gets ruined by floodwater. On Sunday, her family still had electricity, and their street wasn’t completely under water. 

But the others?

“Now they're having to be rescued,” Alston said. “If we had known it would be like this, I think we would've left.”

At least five people have already been reported dead as Harvey, previously a hurricane and now a slow-moving tropical storm, continues to feed rising waters across the nation’s fourth-largest city and its surrounding communities. As the waters strand thousands of folks in their homes and send some onto rooftops, a chorus of onlookers have asked: Why didn’t local officials order mandatory evacuations, as more than a dozen other smaller Texas cities and counties did?

Such a decision is thorny in any community, and it only grows more so in such a sprawling metropolitan area. 

On Friday, with Harvey approaching the Gulf Coast, Gov. Greg Abbott told folks in Corpus Christi and Houston, the two largest cities in the storm's path, to “strongly consider evacuating” northward. While Corpus Christi issued a voluntary evacuation, neither Houston nor Harris County issued any such evacuation order at all.

Ultimately, mayors and county judges are charged with making such decisions. Leaders in Houston and Harris County told residents to stay put ahead of the storm and have since defended those decisions — even as bayous spill into the streets in what might be the worst flood event the area has ever seen.

“To suggest that we should have evacuated 2 million people is an outrageous statement,” Harris County Judge Emmett told CNN on Sunday.

Emmett and others have offered a litany of reasons for hunkering down. That includes the reality that such a mass evacuation can turn into logistical nightmare with huge safety risks of its own. 

“People disproportionately die in cars from floods, so evacuation is not as straightforward a call as seems,” Marshall Shepherd, a program director in atmospheric sciences at the University of Georgia, tweeted Sunday. 

Shepherd pointed to data from the National Oceanic and Atmospheric Administration showing that drivers accounted for 66 percent of U.S. flood fatalities in 2014. 

For a vivid example of what can go wrong in a large-scale evacuation, Texans can look back 12 years to Hurricane Rita, when more than 3 million people from south and southeast Texas set off on one of the largest evacuations in U.S. history.

The backdrop of that blistering summer in 2005: Just three weeks earlier, Hurricane Katrina had submerged New Orleans and killed 1,200 people when Rita barreled toward the coastline. Texans didn’t want to stick around to see how Rita would compare, so they bolted — or tried to.

Traffic jams stretched across hundreds of miles over two days, and many people ran out of gas. Dozens died from accidents and heat-related illnesses, all before Rita even made landfall.

Of the 139 deaths that the state linked to Hurricane Rita, 73 occurred before the storm hit Texas. Twenty-three people died in a bus fire. Ten others died from hyperthermia due to heat exposure. In the years since Rita, state and local officials say new laws and better planning would help the state’s next evacuation go more smoothly, but Houston mayor Sylvester Turner this weekend indicated Rita’s legacy factored into his decision.

“You cannot put, in the city of Houston, 2.3 million people on the road ... That is dangerous,” he said in a news conference Sunday. “If you think the situation right now is bad — you give an order to evacuate, you create a nightmare."

Emmett, the Harris County Judge, has pointed to additional factors in defense of calls to stay, drawing distinctions between danger from Harvey — primarily rainfall — and the hurricanes that struck before it.

“When we have hurricanes, we know who to evacuate because you have a storm surge coming, and we have that down to a very fine art,” he told CNN Sunday. “In this case, we have a rain event. Unless you know where the rain is going to fall, we don’t know who to evacuate.”

While ordering a hurricane evacuation is common, telling residents to flee a rainstorm is rare, if not unprecedented. “We’ve had three major rain events in the past two years. This is now the fourth," Emmett said.

Emmett, in the CNN interview, bristled at those who were pushing conflicting messages. That included retired Lt. Gen. Russel Honoré, who commanded a joint task force that responded to Hurricane Katrina.

“If you are living in an area that’s flooded before, you need to evacuate,” he told CNBC Friday. “Because it’s going to flood, and the roads are going to close and when the roads are going to close, the power is going to go out, and you’re going to be isolated in that home alone.”

Alston, who said she didn’t realize the full scope of the storm until the day before it struck, said it was “mind-boggling to see the conflicting messages from city and state officials.”

Abbott, for his part, said he’s not spending his time second-guessing local officials.

“As far as the evacuation, now’s not the time to second-guess the decisions that were made,” he said at a news conference Sunday. “What’s important is that everybody work together to ensure that we are going to first save lives and then second help people across the state rebuild.”

Harris County wasn't the only Harvey-hit community where residents were told to stay in place. Corpus Christi and Nueces County refrained from calling for mandatory evacuations before the storm took aim Friday. 

Corpus Christi was largely spared from massive property damage and life-threatening destruction when the storm hit farther east along the coast, killing at least one person in Aransas County, where an evacuation order was mandatory.

“I think we made the right decision,” Corpus Christi Mayor Joe McComb said Friday, before the storm hit. “That was after a lot of conversation, a lot of dialogue.”

Alana Rocha, Edgar Walters and Neena Satija contributed to this report. 

Read related Tribune coverage:

• This is already Houston’s "worst flood." It’s only going to get worse. [Full story]

• As Hurricane Harvey made landfall, no area felt the impact as harshly as Aransas County. [Full story]

• Before Hurricane Rita hit the Texas coast in 2005, there was an evacuation marked by a traffic disaster. [Full story]