Posts Tagged ‘Snowmelt’

Early season turnaround bodes well for water supply

Despite a parched start to winter, snowpack levels are on track thanks to a snowy December and early 2017 storms.

Denver Water's Winter Park crew works around the clock to ensure facilities are accessible during snowstorms.

Denver Water’s Winter Park crew works around the clock to ensure facilities are accessible during snowstorms.

By Travis Thompson

Like carpenters, water supply managers use an assortment of tools to get the job done. But instead of tape measures and hammers, their tool boxes are filled with charts and graphs, computer models and good old-fashioned experience.

With 80 percent of Denver’s water supply coming from snowmelt, no tool is used more during the winter months than the charts showing snowpack levels in the mountains above Denver Water’s facilities.

And this year is proving to be one of the more interesting in recent memory.

With more than half of the snow season still ahead, water managers have already seen near historic lows and highs to kick off the winter.

“Our team was starting to sweat a little bit this fall — literally and figuratively — with the unseasonably warm and dry weather,” said Dave Bennett, water supply manager for Denver Water.

In late November, snowpack levels in areas feeding the streams and rivers that flow into Denver’s mountain reservoirs were only 10 percent to 20 percent of normal.

Denver Water’s reservoirs were still above average because of the good water years carried over from 2014 and 2015, as well as efficient water use in the Denver metro area.

But the dry start to winter had Denver Water planners on edge.

“I knew that a couple of good storms would have us back to normal,” said Bennett. “It was too early to panic — well, that’s what I kept telling myself at least.”

Thankfully, he was right.

On Jan. 5, water supply manager Dave Bennett talked to 9News reporter Colleen Ferreira about the improved snowpack levels in Denver Water's collection area.

On Jan. 5, water supply manager Dave Bennett talked to 9News reporter Colleen Ferreira about the improved snowpack levels in Denver Water’s collection area.

In December, Denver Water’s Colorado River basin collection area received almost double the amount of accumulation than normal, with approximately 60 inches, making it the sixth snowiest December for this area over the past four decades.

Similarly, the South Platte River basin collection area that feeds Denver’s reservoirs received approximately 40 inches of snow compared to the normal 20 inches, making it the fifth snowiest December in this location over the same 40-year time period.

Couple that with the early 2017 snowstorms, and snowpack levels are now 137 percent and 128 percent of normal in the Colorado River and South Platte River watersheds — and, it’s still snowing!

It was such a significant turn of events that Bennett was featured on 9News, talking about the importance of the recent snow, not only for water supply but also for Colorado’s greatest asset: outdoor recreation.

“I’ve never seen an early season turnaround like it,” said Bennett. “But we still have a long way to go. A lot can happen between now and spring — the months we rely on the most for snowpack are still ahead of us.”

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Warm weather, wildfires and watersheds

How reducing the risk of catastrophic wildfires improves the quality of water flowing into our reservoirs.

By Steve Snyder

Not cool, bro.

Land near Cheesman Reservoir was severely damaged after the 2002 Hayman Fire.

Watershed lands near Denver Water’s Cheesman Reservoir were severely damaged after the 2002 Hayman Fire.

That’s one way to describe the warm, dry fall we experienced in Colorado this year, not only from a temperature standpoint, but from a broader view of what these conditions mean to our water supply.

Denver Water gets almost all of its supply from mountain snowmelt, so the lack of snow so far is a bit concerning. But weather like this also has a big impact on another part of our system — our watersheds. As melting snow travels downhill, it may pass through forests, farmland and even commercial, industrial and urban areas. This land is called a watershed, and it directly impacts the quality of water that eventually gathers in Denver Water’s reservoirs.

And warm fall weather only increases the risk of wildfires in our watersheds. In fact, a recent paper in Proceedings of the National Academy of Sciences suggests the effects of climate change are making forests in the Western United States drier and easier to burn, thus increasing the risk for large, catastrophic wildfires.

“Catastrophic wildfires in our watersheds have impacts on so many levels,” said Christina Burri, a watershed scientist at Denver Water. “They are devastating for communities and the environment, but they also impact our water quality. When water runs through watersheds scorched by catastrophic fires, rainfall picks up sediment and ash which harms the water quality in our streams and reservoirs.”

Climate change makes it even more challenging to protect watersheds against catastrophic wildfires, she said. “This year is a perfect example. The wildfire season is longer, and the risks are greater.”

But Denver Water works with other agencies and local communities to mitigate those risks, Burri said.

From Forests to Faucets, a partnership between Denver Water and the U.S. Forest Service, focuses on forest treatment and watershed protection projects in priority watersheds critical to Denver Water’s water supply.

Through the Upper South Platte Partnership, Denver Water works with local landowners, government officials and other community members to manage forests and protect and improve the health of the watershed in counties where our water supplies flow.

And Denver Water planners work directly with communities to ensure public drinking water resources are kept safe from future contamination. Denver Water worked with the Colorado Department of Public Health and Environment and the Coalition for the Upper South Platte to create a source water protection plan for the Upper South Platte Watershed and implement that plan with Park, Douglas, Jefferson, and Teller counties.

A restored and thinned forest in Jefferson County in the Upper South Platte Watershed.

A restored and thinned forest in Jefferson County in the Upper South Platte watershed is much less susceptible to catastrophic wildfires.

“Our watersheds are the first filter through which our source waters run,” said Burri. “We have a really good source of water in our system, but if we don’t have a healthy filter for it, it causes more challenges down the line when we treat water. We have to make sure those filters are in the best shape possible.”

Preserving the environment and promoting high-quality water. Now that is cool, bro.

Releasing water in the middle of a drought?

California does it, and so do we. It’s all part of managing a complex water system.

By Dana Strongin

Even in times of severe drought, sometimes a water system has to know when to let go.

Consider the conundrum in water-challenged California, where operators recently doubled the amount of water flowing out of federally run Folsom Lake, a Northern California reservoir.

“You can’t hold on to every drop,” said Shane Hunt, a spokesman for the Bureau of Reclamation, which runs Folsom.

AnteroJune2015_close

Water drains out of Antero Reservoir in June 2015 as part of preparations to rehabilitate Antero Dam.

Why would a water system release such a precious resource? We put the question to Nathan Elder, water resource engineer at Denver Water.

“The main benefit of drawing a reservoir down early is to be able to control releases from the reservoir,” Elder said. From a system view, opening space in one reservoir may create the flexibility to fill all of the reservoirs during the runoff season.

Call it science or a miracle, we are blessed to have the gift of Mother Nature’s snows as our primary source of water.

Denver Water’s mountain collection system spans about 4,000 square miles and houses a lot of infrastructure — facilities that cannot all be online all of the time. Maintenance and improvement projects, such as upgrading the outlet works at Dillon Reservoir and rehabilitating Antero Dam, are critical to keep the system working well into the future.

Operating reservoirs requires careful thought — including balancing many other important considerations, such as water supply, safety, recreation, the environment and hydropower.

With all of the complexities our planners consider, they can count on one simple fact: Every spring brings warmer weather, and most of the mountain snow will melt. We need a place to put that water to store it for future use.

DillonMay2009_making_room

Dillon Reservoir sits low in May 2009, after operators released water to make room for runoff.

Dillon Reservoir offers a good example. In early February 2014, when Dillon was 94 percent full, we started to make room for the robust runoff expected with snowpack at 163 percent of normal. And in late January 2015, because the reservoir was 99 percent full and we had a healthy snowpack, we began to slowly lower the reservoir.

It’s starting to happen again this year. Dillon Reservoir is 93 percent full, and snowpack above it is 108 percent of normal. In late February we began letting out more water to slowly decrease the reservoir level and benefit hydropower production at the same time. It’s possible we could decide later to release water at a higher rate to make more room for runoff.

But it’s way too early to know for sure. Denver Water operators keep their eyes on the skies and weather forecasts so they can stay nimble if conditions change quickly.

Either way, releasing reservoir water is not necessarily a loss. “Water released from Dillon is used to generate hydropower,” Elder said. “If conditions present themselves, releases can be managed and timed to prolong rafting season on the Blue River.

“The water may not go to customer’s taps, but that does not mean it is not put to use.”

Why we love juicy flakes (and you should, too!)

Not all snowflakes are created equal; some have more love to give.

By Jay Adams and Kim Unger

When the snowflakes begin to fall, we’re guessing the last thing on your mind is moisture content. Isn’t all snow created equal? Turns out, there is a big difference between the type of snowflake and how much moisture it will produce — which makes a difference in filling our mountain reservoirs. Check out our infographic to see why juicy flakes are best.

 

infographic-snowflakes-waterContent-reservoirs-v6

El Nino: Helping hand or just a lot of hot air?

Snow in Colorado. Rain in California. Is El Nino the cause, and can it keep the water coming?

By Steve Snyder

Too big to fail.

No, this isn’t about enormous financial institutions. We’re talking about the biggest, baddest El Nino weather pattern we’ve seen in years.

This year’s version of the warming surface water in the Pacific Ocean was supposed to blast much of California and other western states with potentially record-setting moisture. If you’re keeping up with climate news, California in particular could use the water.

This map of a typical El Nino weather pattern shows Colorado right on the edge of moisture impacts. (Courtesy: National Weather Service)

This map of a typical El Nino weather pattern shows Colorado right on the edge of moisture impacts. (Courtesy: NOAA)

And so far, so good, at least in terms of moisture content. But the key words are “so far,” as even this supersized El Nino hasn’t made a huge dent in the Golden State’s decade-long drought.

So why is Denver Water watching the weather in California so closely? One reason is that water resources for Colorado and California are closely linked. Any moisture California gets is good for Colorado and the entire Colorado River Basin.

We’ve seen a lot of moisture in Colorado this winter, too, and it has really helped our snowpack. But how much is our winter wonderland related to our warm-blooded friend in the Pacific?

“It’s difficult to credit El Nino for all of our weather this winter,” said Laurna Kaatz, climate adaptation program manager for Denver Water. “El Nino typically increases precipitation across the southwest, and our Rocky Mountains are right on the fringe of this area. So El Nino can influence our weather, but it’s not the only factor.”

It’s also difficult to predict what the rest of the winter and early spring will bring in terms of moisture for Colorado, as each El Nino pattern is different. But there are some historical patterns to study.

“Past El Nino cycles have usually brought moisture to Southern Colorado,” Kaatz said. “The three-month outlook calls for above-normal precipitation in Colorado, but nothing is certain here in terms of weather, given our location and topography.”

Of course, as long as the snow keeps piling up in our mountains, we don’t care if it’s El Nino or El-Nacho Libre causing the stir. We’ll take all we can get, especially with Colorado’s unpredictable weather.

Our party starts now

From mucky messes to bears in the road, see the scenes that sizzled (and drizzled) in our 2015 water year.

By Dana Strongin

One-fourth of your year may be left, but Denver Water’s 2016 has already begun. The water year calendar of October through September dictates much of our work, which cycles with the seasonal conditions that drive reservoir storage and water use.

It’ll be a while before your New Year’s Eve party, so feel free to join ours. Check out these photos to see some of the wonders and oddities that we saw in 2015’s water year.

Note: This slideshow may not work depending on the type and configuration of your Web browser. If that’s the case, click here to view it.

The “why” behind our fluoride policy

Denver Water’s board decided to continue community water fluoridation by weighing the evidence. Now you can, too.

By Denver Water staff

Denver Board of Water Commissioner members listen to information at the July 2015 fluoride information session.

Denver Board of Water Commissioners listen to information at the July 2015 fluoride information session.

In the end, it came down to the science. And there’s a lot of it.

On Aug. 26, the Denver Board of Water Commissioners voted to continue its practice of community water fluoridation.

That decision was not entirely unexpected. Denver Water has been regulating fluoride in the water since 1953, but board members said they took opposition to the policy seriously and requested a review of the latest science from the foremost national and local authorities to inform our policy.

Fluoride naturally occurs in many of Denver Water’s supply sources. We add fluoride as necessary to achieve an average concentration equal to the target recommended by the U.S. Public Health Service and the Colorado Department of Public Health and Environment.

Earlier this year, opponents of water fluoridation began appearing at Denver Water board meetings, urging commissioners to end the practice. In response, the board held a fluoride information session on July 29 and encouraged public input. Many individuals and organizations submitted comments and reference documents.

“We are just trying to educate people on this issue,” said Greg Gillette, a spokesman for We are Change Colorado, a group urging Denver Water to stop adding fluoride to water. “We hope everybody has an open mind.”

After reviewing the presentations, the extensive research on this issue, and the advice of public health and medical professionals in Colorado, the board announced there would be no change in its water fluoridation policy.

The resolution the board adopted at its meeting stated: “Nothing we heard through the presentations or learned in research would justify ignoring the advice of the public health agencies and medical organizations or deviating from the thoroughly researched and documented recommendation of the U.S. Public Health Service.”

Denver Water Commissioner Greg Austin went on record saying, “After careful consideration of the information put forth by both sides of the fluoridation debate, I am convinced that the community water fluoridation level recommended by the U.S. Public Health Service provides substantial health benefits, and is a safe, cost-effective and common sense contribution to the health of the public.”

The research on fluoridation is quite extensive. Here’s a sample of what board members and Denver Water staff reviewed:

  • The work of the Federal Panel on Community Water Fluoridation. This group of physicians, epidemiologists, environmental health experts, dental professionals, toxicologists, statisticians and economists re-examined water fluoridation levels.
    • In 2011, the U.S. Public Health Service published a proposed recommendation based on the conclusions of that panel.
    • The Public Health Service then received thousands of comments opposing community water fluoridation, raising the same categories of objections as those submitted to Denver Water at our public forum and during the public comment period.
    • The Panel did not identify compelling new information to alter its assessment that fluoride levels of 0.7 milligrams per liter provide the best balance of benefit to potential harm.
    • In May 2015, the Public Health Service issued its final decision document, adopting a recommendation to change to a single target fluoride concentration of 0.7 milligrams per liter.
  • Letters, documentation and personal stories from public and professional health organizations and medical professionals supporting the continuation of community water fluoridation. Notably, every public health agency operating in our service area urged us to continue our practice of managing fluoride concentrations in our drinking water.

Commissioners also noted that if Denver Water stopped managing fluoride levels, our customers would still be drinking fluoridated water.

“But the levels would vary significantly, creating an imbalance throughout our service area,” Denver Water Commissioner Penfield Tate said. “Community water fluoridation provides dental health benefits across all socioeconomic communities in a predictable and uniform manner.”

Filter beds at a Denver Water treatment plant. Fluoride is added after filtration, prior to disinfection. Learn more about the treatment process: denverwater.org/WaterQuality/TreatmentProcess

Filter beds at a Denver Water treatment plant. Fluoride is added after filtration, prior to disinfection.

“Community water fluoridation is a public health action, which by definition protects the health of the population in general, and sometimes conflicts with individual choice,” said Denver Water General Counsel Patricia Wells. “Those who object to fluoridated water do have alternatives, such as nonfluoridated bottled water or in-home filtering systems.”

With their decision, the commissioners said they were relying on experts who bear the responsibility to protect the health of the public. Community water fluoridation provides health benefits to all our customers, at all stages and ages of their lives, regardless of their access to health care or their adherence to healthy living guidelines.

Denver Water consumers can inform themselves about fluoride levels in their water by accessing readily available public information on our website.

 

 

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