#Runoff news: Lake City prepares and waits, so far so good

The historic Hidden Treasure Dam above Lake City on Henson Creek will be removed to avoid a surge of debris which could impact the community of Lake City. Efforts will begin immediately. Hidden Treasures Dam owners, the Hurd Family, made the hard decision to remove the dam after it was determined it would likely not survive the high flow spring runoff. The decision was made following analysis conducted by an advisory group which included the Hurd Family as well as representatives from the Bureau of Land Management, Colorado Office of Emergency Management, Hinsdale County, Town of Lake City, Colorado Geological Survey and Colorado Division of Water Resources – Dam Safety. All available options to save this historic structure were considered. The Hidden Treasure Dam dates back to the 1890s when both the Hidden Treasure and Hard Tack mines were in operation. Photo credit: Hinsdale County

From The Denver Post (Elise Schmelzer):

Lake City, the only town in remote Hinsdale County, is one of many rural Colorado communities working to prepare for potential flooding as the winter’s epic snowpack begins to melt. Mountain towns across the state are preparing sandbags and warning visitors about high water…

Although numerous mountain towns have prepared for high water, Lake City’s predicament was particularly dire and threatened lives before the emergency crews arrived, state officials said.

More than 60 avalanches, some more than a half-mile wide, pushed mountainsides of trees, boulders and snow to the floors of the two river valleys surrounding the town, which sits at the confluence of Henson Creek and the Lake Fork of the Gunnison River…

Authorities feared a wall of water could build if the logs jammed or blocked one of the two historic dams. If the debris jam or dam were to break, the surge of water sent downstream could send feet of water into some of the low-lying areas of town within 15 minutes.

At a town meeting Tuesday, officials estimated there was a 10 percent chance that the worst-case scenario could happen if weather conditions aligned perfectly and predicted that high water could begin as early as this weekend. Federal, state and local officials have worked in the city for a few weeks to mitigate the chance of such a surge, including partially deconstructing one of the dams…

Lake City residents knew the avalanches around their town of about 400 people this past winter were unprecedented. The avalanches in February and March caused voluntary evacuations and flattened the Hinsdale County sheriff’s house outside town.

But it wasn’t until crews in April started exploring the two mountain roads along the river valleys that the size of the avalanches became apparent. Piles of centuries-old trees, snow and boulders covered sections of roads up to a half-mile long…

Mitigation efforts have been broad. Personnel from the group of agencies built a berm along one of the rivers in town. They partially destroyed one of the historic dams so water could flow better. They also placed additional sensors along the rivers so the flows could be monitored in real time. They helped organize the filling and deployment of more than 18,000 sandbags around town to protect important buildings. Crews surrounded the most vulnerable homes near the confluence with 3,000-pound mega sandbags…

Engineers recommended that the town demolish the 129-year-old Hidden Treasure Dam because they worried that avalanche debris could block the dam and cause it to fail, sending a rush of water toward town. Contractors used a remote-controlled jackhammer suspended on a sling to chip away at the top of the dam and small explosives to blast away the bottom.

But engineers later determined the new gaps at the top and the bottom were big enough to avoid a jam…

Signs along the Rio Grande on Wednesday prohibited anybody — or any boat — from entering the raging water. Along Colorado 149, the river overtook tree trunks and washed out boat ramps, but left houses untouched. Campgrounds and some roads in the area remained closed.

Mineral and Rio Grande counties, as well as sections of Conejos and Saguache counties, remained on flood watch Thursday. Officials in Chaffee and Summit counties, as well as the towns of Silverthorne, Buena Vista, Avon and Ouray, have opened sandbag stations…

In Creede, about 50 miles southeast of Lake City, waters have taken over the floodplain but haven’t threatened any structures, said Kathleen Murphy, director of the town’s chamber of commerce. The city worked last week to widen a concrete flume that directs water through town. A road north of town washed out after avalanche debris built up, releasing a surge of water. Some lower-elevation hiking trails were flooded as well.

From The Summit Daily News (Allen Best):

In Colorado, where snow still blankets the San Juan Mountains, the Durango Telegraph has proclaimed El Niño as the winner of this year’s Hardrock 100. The race was scheduled for mid-July.

Organizers canceled the 100-mile foot race among the peaks of the San Juans around Silverton owing to “unprecedented avalanche debris, unstable snow bridges and high water” that compromised 40 miles of the race course.

It was the third time in 27 years that the race had been canceled, the first being in 1995 because of too much snow and then in 2002 because of forest fires.

At the California Weather Blog, meteorologist Daniel Swain suggests a big view of weather extremes across North America: floods in Nebraska, tornadoes in Oklahoma, a massive forest fire in Canada and record heat in the Arctic. They’re all connected, he points out.

Emerging evidence suggests that such weather extremes may be occurring with greater frequency and intensity as the Arctic continues to warm faster than the rest of the planet.

“Interestingly, though, this doesn’t necessarily mean that the impacts we experienced in 2019 will be exactly the same the next time this pattern repeats,” Swain wrote on his blog. Every iteration of the “wavy jet stream” produces new patterns of warmth vs. coolness and very wet vs. very dry.

From KOAA.com (Tyler Dumas):

The Arkansas River keeps rising in Fremont and Pueblo Counties.

10 feet is considered flood stage in Canon City and the river reached that level at 8:30 a.m. Saturday morning. Minor flooding is expected in flatter areas, like along Raynolds Ave.

In Avondale, flood stage is considered 7 feet, which was reached around 11 p.m. Friday night…

Parks and Wildlife has closed off the river below the dam at Lake Pueblo State Park to swimmers and all non-whitewater boats, including inner tubes and kayaks.

Law enforcement in Pueblo has also closed off the river east of Pueblo Blvd. to the Otero County line because of fast-moving water.

From InkStain (John Fleck):

The Bureau of Reclamation’s monthly storage model runs, based on the latest Colorado River Basin runoff forecasts, show Lake Powell ending the water year (Sept. 30) at 13.8 million acre feet. That’s an increase of more than a million feet over the May estimate, and 2.8 million acre feet above the Sept. 30, 2018 number:

From email from Reclamation (James Bishop):

Releases from Green Mountain to the Blue River will increase according to the following schedule starting at midnight [June 15, 2019] (cusp between 15 and 16 June):

12:00 a.m. Adjust release from 1100 cfs to 1200 cfs
3:00 a,m. Adjust release from 1200 cfs to 1300 cfs
6:00 a.m. Adjust release from 1300 cfs to 1400 cfs

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