Floodwaters be contaminated with debris as well as high levels of bacteria, chemicals, waste and other pollutants, which can cause prolonged health risks, experts say.

Kerr County failed to secure a warning system, even as local officials remained aware of the risks and as billions of dollars were available for similar projects.

Numerous scattered showers and storms will continue in the area through Sunday, with pockets of heavy rain and an increase in the risk for flash flooding.

At least 27 campers and counselors at Camp Mystic perished in Friday's floods, with the total death toll in the floods now surpassing 100.

Camp Mystic owners successfully appealed to the Federal Emergency Management Agency to redesignate some buildings that had been considered part of a flood-hazard zone.

Some regions in the mid-Atlantic are also facing risks of flooding. On Sunday, Tropical Storm Chantal flooded parts of North Carolina, where more than 10 inches of rain fell near the Chapel Hill area. The Haw River, near Bynum, North Carolina, crested to nearly 22 feet, the highest crest on record there, as a result of those heavy rains.