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How Pineview Dam plays critical role in preventing flooding

By Jed Boal, KSL TV | Posted - May 19th, 2019 @ 10:27am


2 photos

OGDEN — With all the snow that piled up in Utah’s mountains this year, flood concerns have been on the minds of many water managers.

Numerous dams collect and store the water for us to use in the summer when the precipitation dries up, but the dams also protect lives and property from flooding.

The Ogden River below Pineview Dam is running fast, but well within its channel right now. Without the dam, in years like this with high runoff it’s unlikely anyone could live in the canyon with an uncontrolled river roaring through.

"Every year is different, so we just have to roll with the punches," said Darren Hess, chief operating officer of Weber Basin Water Conservancy District.

Pineview Reservoir is filling up this spring after being drawn down to only a third of capacity last fall. It stores water for the Weber Basin Water Conservancy District, which operates the dam built by the Bureau of Reclamation.

"Every one of our dams has a flood control benefit,” said Wayne Pullan, Provo-area manager for the Bureau of Reclamation.

It’s a balancing act using the dam for storage and flood control.

"We need to make sure that we fill the reservoir in a year like this, and we don’t release too much water,” said Hess. “But we also need to make sure that we release enough water so that we create room to catch those higher runoffs when it really warms up.”


All of that would be coming down on Mother Nature’s timetable. With this dam here, it comes down in a way that we can control it.

Above the reservoir, the south rork of the Ogden River is boiling with rapids from the runoff. It’s the most swollen river in our state, right now, flowing at 85 percent of flood stage Wednesday. It was forecasted to peak in the next five days at 93 percent of flood stage. Without the Pineview Dam, that water would not be stored. Plus the raging river, unchecked by the dam, would wash away structures and homes in Ogden Canyon, if they could even be built there.

"All of that would be coming down on Mother Nature’s timetable," said Pullan. "With this dam here, it comes down in a way that we can control it."

The dam was originally built in the 1930s, and then re-built in the 1950s by the Bureau of Reclamation, partly with federal money specifically for flood mitigation.

It’s 91 feet tall and about 300 feet wide. It’s an earthen dam constructed mainly of large rocks and other natural materials. The dam’s capacity is 110 acre feet, right now holding about 85 percent of that.

Two months ago, due to the deep snow up in the mountains, it seemed inconceivable to the water managers that there would not be some flooding somewhere in Utah. But, cold and cool weather, punctuated by bursts of heat has stretched out the runoff period. Combined with flood mitigation strategies, that has helped most flood-prone communities avoid problems this spring, so far.

Photo: KSL TV

"Mother Nature throttles the temperature up and back down, and up and back down," said Pullan. "It allows the lower elevation snow to come off, and then the mid-range snow to come off, and then the high range snow, so you don’t have them all coming off at once."

Two weeks ago, Weber Water reached the maximum release of water from the dam, probably averting further flood concerns for the Ogden River.

"It looks like we reached the peak on the Ogden River," said Hess. "It all depends on the weather."

The forecast calls for another cool down, more rain and warming again next week. There is still high elevation snowpack to come down other rivers statewide. The weather and flood mitigation strategies have worked to hold back flooding, so far.

Photos

Jed Boal

KSL Weather Forecast