Kerr County had discussed buying such things as water gauges and sirens after previous flood disasters. But as with many rural Texas counties, cost was an issue.

A flood warning was issued by the National Weather Service on Tuesday at 6:21 a.m. in effect until 10:30 a.m. for Delaware County.

Mr. Trump and Melania Trump met with victims’ families and viewed some of the aftermath of last weekend’s flooding.

Despite the rising threat of climate disasters like last week’s deadly flash flood in Texas, the vast majority of America’s waterways are still not being monitored by water level gauges that help identify impending disasters.

A flash flood warning is issued when a flash flood is either imminent or already occurring. In flood-prone areas, it's crucial to move immediately to higher ground. A flash flood is a sudden and violent inundation that can develop within minutes to hours, and it can even happen in areas not currently experiencing rainfall.

At a news conference on Sunday, Governor Greg Abbott said people in Texas were used to flash flood warnings, but there was no sense of how deadly this would be. "There's no expectation of a water wall of almost 30ft high," he added.

KERRVILLE, Texas (AP) — Over the last decade, an array of Texas state and local agencies missed opportunities to fund a flood warning system intended to avert a disaster like the one that killed dozens of young campers and scores of others in Kerr County on the Fourth of July.

"Flood waters have receded. The heavy rain has ended. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures," according to the National Weather Service.

The National Water Center warned several rivers would face serious flooding by Friday afternoon, including the Colorado River near San Saba, Texas; the Guadalupe River near Comfort, Texas; the Guadalupe River near Kerrville, Texas; and the Guadalupe River near Hunt, Texas.

A flood watch was in effect July 7 for several states, including Virginia, Maryland, Delaware, New Jersey and Pennsylvania. "Storm total rainfall of 2 to 4 inches, with local amounts up to 6 inches, is expected," the Weather Prediction Center said in a 5 a.m. ET update. "An elevated risk for flash flooding will continue."