Enterprise Stories-What if the Dam Breaks? Enterprise on Flood Watch in 1993

About a month ago, our family went for a ride to the Enterprise Reservoir. We were in hopes to find both reservoirs somewhat fuller than they had been in the summertime when we were there last. Sadly, we found both reservoirs very low and looking more like ponds than lakes.

The Upper Enterprise Reservoir in March 2016. ~ Photo:Stacee Seegmiller

The Upper Enterprise Reservoir in March 2016. ~ Photo: Stacee Seegmiller

Seeing the reservoirs so low was disappointing to say the least. As we turned around to head back home, I started thinking of a time in 1993 when the reservoirs were overflowing and the town was preparing for the worst scenario possible: the dam breaking. Below is an article that appeared in the Deseret News on March 9, 1993, regarding the full reservoirs that had many people wary.


Deseret News

By Lisa Riley Roche and Matthew S. Brown, Staff Writers

Published: Tuesday, March 9, 1993

Enough snow is ready to melt above the Upper and Lower Enterprise reservoirs to fill each 14 times over – and that’s if both were empty.

But after a long, wet winter, the reservoirs, like others in the area, are full. Worse, the 106-year-old Lower Enterprise Dam is leaking from narrow gaps as long as 19 inches after last year’s earthquake. The crumbling masonry, combined with the likelihood that the dam will overflow, has local, state and federal flood control officials worried about the town of Enterprise, just 7 1/2 miles downstream.

On Monday, Gov. Mike Leavitt flew by helicopter over areas of Washington and Iron counties threatened by flooding if the region’s warm temperatures continue. Rains forecast for later in the week are expected to worsen the chance of a torrent.

Temperatures are expected to stay in the mid-70s through Friday in St. George, with very little rain forecast through Saturday, said Tim McClung, a meteorologist at the Salt Lake office of the National Weather Service.

Leavitt, who’s from the area, was surprised by what he saw during his hourlong tour. “There’s more snow than I’ve ever seen before. It appears to me the real movement of water hasn’t begun. When it does, we need to be ready.”

An interagency flood evaluation team, made up of local, state and federal officials has been on the scene since Thursday, inspecting dams, reservoirs, rivers and flood channels.

Flood risk map shown in original article. ~ Deseret News

Flood risk map shown in original article. ~ Deseret News

Their report to the governor identified St. George, Santa Clara and Washington City as well as Enterprise as the main communities at risk. Hurricane, Virgin, Springdale and Toquerville are not in as much danger.

The Lower Enterprise Dam is a special concern because of the leaks. The problem is that mortar holding together the heavy stones has been worn away, leaving gaps.

The snowpack in the Pine Valley Mountains above Enterprise is 1,600 percent of normal this year. Basinwide, the snowpack is 300 percent of normal with a record water content of up to 40 inches.

A computer simulation showed a wall of water more than 13 feet deep could reach Enterprise in just 48 minutes if the dam breaks, Bill Self, regional dams and hydrologics engineer for the U.S. Forest Service, told the governor and other officials.

The dam was built in 1887 and was exceptionally well-designed for its time, according to Self.

Self said a dam that old is bound to have problems and needs to be overhauled. He said he has been monitoring the dam for some time and will return Wednesday and again on Friday to check it.

The Lower Enterprise Reservoir overflowing. Date unknown. ~ Photo: Cody F http://aroundguides.com/23430834/Photos/36254287

The Lower Enterprise Reservoir overflowing. Date unknown. ~ Photo: Cody F. http://aroundguides.com/23430834/Photos/36254287

But many local residents believe the quality of craftsmanship used in the dam’s construction will keep it from collapsing even in the worst of conditions, Self said.

“It’s a really good dam, I think,” said Enterprise Mayor Merrill A. Staheli. “I’m not worried about it breaking.”

Despite their pride and confidence in the old dam, Staheli and other residents are preparing for the worst.

Staheli said a response plan is in place, and the volunteer network of local LDS Church wards is poised to assist widows and elderly.

“We’ve activated our siren. If it’s a long ring then a member of each family meets at the (LDS Church’s) stake center for instructions. If the ring’s up and down then everyone evacuates,” he said.

Residents also are filling thousands of sandbags with sand trucked in last week by the Utah Department of Transportation. Sandbag dikes are being erected in front of homes near the Shoal Creek Wash, where mountain runoff flows as it makes its way into the Escalante Valley.

Farmers in the area could lose crops or worse, their homes, if severe flooding occurs. Lowel and Gina Day, who raise alfalfa in the wash, said snowmelt already flooded their fields about two weeks ago.

“The lower end of the farm was like a lake,” Gina Day said. The water stood for just 24 hours before soaking into the ground. Unless the dam breaks, the Days said their family and livelihood will be safe.

“Ain’t too much to be concerned about,” Lowel Day said. “If it does it, it does it.”


Article source: http://www.deseretnews.com/article/279581/FULL-RESERVOIRS-CRUMBLING-DAM-HAVE-FLOOD-WATCHERS-WORRIED.html?pg=all

Feature Photo: Rusty Hunt http://aroundguides.com/23430834/Photos/44969537



Stacee Seegmiller

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