SANTA CLARA, Washington County — A breach in a retention basin caused a surge of water to flow into a Santa Clara neighborhood Tuesday, resulting in flood damage to at least 25 homes and a dozen businesses, forcing residents to evacuate.
The dike, categorized as a high-risk dam once homes and businesses were built below it, was scheduled to be rebuilt before it spilled over Tuesday, said Ron Whitehead, Washington County public works director. The basin originally was built to protect the nearby highway, but expansion gradually surrounded it with structures.
"It's just been there for years," Whitehead said. "We never had a problem with it. It never filled up as fast as it did like this. Today we had some big thunderstorms that put a lot of water over the drainage area and just filled it up fast, and it wouldn't hold."
Whitehead, who witnessed the dike break Tuesday, said water began seeping through the top of the dam as the earthen face eroded and pressure built up behind it. The breach sliced slowly downward to the rock base, widening as it went, he said.
Whitehead couldn't estimate how much water spilled through the breach, but he said the flow turned a Santa Clara park into a pond.
"If it were to rain again like it did this morning and there's big drainage that would fill it up like that, it would cause some more severe damage," he said.
With more storms in the forecast, any additional flooding will pour straight through the wound in the dike, Whitehead added.
"There is tons of damage between my yard and my neighbor's yard and the yard down from me," said Ivins resident Andrew Hawk. "I mean, we're going to have to completely rebuild our front yards. We both have bridges that we access our houses from. They're completely ripped out."
Hawk said the flow of water was "absolutely unreal." He estimated a bed in front of his home collected 10 feet to 12 feet of water in about a half an hour Tuesday.
Skyler Ray faces similar damage to his home, something he feared as he heard and then saw the flood approaching.
"I saw the first wave of water just crushing by this street and realized, 'Holy cow, I don't have flood insurance,'" he said.
Ray managed to save important documents in his home and then proceeded to help clear a foot of water from his in-laws' house.
As word of the breach spread, Wendy Basso and her husband headed for their home, which has seen previous flooding.
"We began to worry," Basso said, "and as we headed home, we heard the mandatory evacuation. They wouldn't let us on our street to drive, so my husband and I walked through our backyard. The water was running through like a river on four or five homes."
The Bassos grabbed what possessions, photos and documents they could from the basement, just as the water began to pour in. They won't know the extent of the damage until cleanup begins.
It was only a matter of time before the dike gave way, Basso said.
"It was an earthen dam, and sooner or later everyone said, 'It's going to have to go,' and it went today," she said.
Rep. Dave Clark, R-Santa Clara, the former speaker of the Utah House, has lived near the earthen dike, not far from Snow Canyon Middle School, for 25 years. Clark said he can't remember a time when it was so full, so fast.
"I'm just astonished. I've seen it full only a half-dozen times," he said, adding that his home on high ground was spared.
But in the past week, including Tuesday morning before the break, Clark said he had seen the retention basin full twice. When full, Clark estimated the dike held an area of water that was about 30 feet deep and 100 feet wide at its widest part.
Clark said he recently noticed small signs of leaking, but nothing that would have raised alarm.
But by Tuesday afternoon, city engineers had predicted it would collapse. The breach in the dike was 60 feet to 80 feet wide at the base, Clark said.
KSL meteorologist Kevin Eubank said the Santa Clara area experienced significant rainfall in a relatively short time Tuesday morning. Almost 1 inch of rain fell in St. George, while between 1½ inches and 2 inches of rain fell onto the nearby mountains that feed into the Santa Clara and other rivers.
"Those red rocks are beautiful, but they don't absorb much," Clark said. The torrents threatened an area that he called "probably the nicest neighborhood in Santa Clara."
The National Weather Service issued a flash flood warning for parts of Washington and Wayne counties at 1:45 p.m. A flash food watch was in effect for much of southern Utah through 11 p.m.
County officials also closed several roads due to washed out portions and potential damages that could not be fully assessed until Wednesday.
Eubank said additional rainstorms are heading northeast from Las Vegas toward the St. George area and are expected to move up the I-15 corridor.
The Red Cross provided support Tuesday for a temporary evacuation center in the Santa Clara City Building, 2603 Santa Clara Drive.
Volunteers also turned out to help, reminiscent of the recent effort that followed the Saratoga Springs mudslide. Just before 8 p.m. Tuesday, Washington County Emergency Services mentioned that additional volunteers would not be needed until Wednesday morning.
Emergency officials said the flooding is being caused by a different problem from what was experienced in 2005. In that massive round of flooding, 34 homes were washed into the Santa Clara River or otherwise damaged after a wave of storms that caused an estimated $180 million in damage in the Green Valley area of St. George.
Contributing: Pat Reavy