Archive for the ‘Water Planning’ Category

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.”

snowpack-combined-stacked

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.

Big drilling rigs in Denver: It’s not what you think

Fracking, new supply, noise? The truth about Denver Water’s effort to look deep underground for new places to store water.

By Jay Adams

 

 

For the past century, Denver Water has looked to our mountain reservoirs to store water. But there may be another way to save our most precious resource for future use — right under our feet.

This fall, Denver Water will drill boreholes at four locations in Denver to test a process known as Aquifer Storage and Recovery, or ASR. The technique involves pumping treated water underground into aquifers during wet years and pumping it back up to the surface in times of drought.

Denver Water drilled four boreholes in 2015, but engineers determined additional samples were needed to gather more information about the rock under Denver.

“There are years when our reservoirs fill and spill,” said Bob Peters, water resource engineer for Denver Water. “Those are the years when we would take water from our distribution system and store that water underground.”

Bob Peters, water resources engineer, at an ASR testing location in Denver.

Bob Peters, water resources engineer, visits an ASR drilling test site in Denver.

Storing water in underground aquifers may provide another option as part of Denver Water’s long-term strategy to prepare for future demand challenges including population growth and climate change.

“We might see very large gaps between our supply and demand as we look into the future, so we need to look at all possible water storage options,” said Peters.

Crews are drilling down into the Denver Basin, a collection of aquifers that can stretch more than 2,000 feet under the surface, to investigate the basin’s water-bearing and storage capacity. The basin covers an area of roughly the size of Connecticut, stretching from Greeley to Colorado Springs and from Golden to Limon.

The tests are necessary because few details are known about the rock formations under Denver.

Geologist Cortney Brand, vice president of strategic growth at Leonard Rice Engineers, is working with Denver Water on the project. He compares the rock underground to a sponge. “We know the rock can hold water. We want to know if it’s economically feasible to put water in and take it out,” Brand said.

Aquifer water storage is a more sophisticated version of what people have been doing for centuries. Projects are currently in use or under study by several communities along the Front Range, including Colorado Springs, Highlands Ranch and Castle Rock.

There are two misconceptions about the big rigs people in Denver may see this fall:

The drilling tests are needed to determine the feasibility of storing water in the Denver Basin.

The drilling tests are needed to determine the feasibility of storing water in the Denver Basin.

No. 1: This is not fracking. While rigs may look similar to oil and gas rigs in northern Colorado, Denver Water is not fracking. “All we’re doing is collecting data on the groundwater aquifers that are right below our feet,” Peters said.

No. 2: Denver Water has no plans to tap into the basin for additional water supply. This project is entirely about finding a place to store excess surface water for when we might need it, Peters said.

“There are a number of benefits to underground storage,” Peters added. “You don’t have to build a new dam, it’s comparatively less expensive, there’s minimal impact on the environment and there’s less evaporation.”

The additional findings will help determine if using the aquifer for storing and extracting water is economically feasible. If results of the new bore tests are promising, Denver Water will decide whether to build a pilot well facility to continue studying the feasibility of ASR. This facility could be operational by 2019.

“This is future water supply planning in action,” Peters said. “There are always uncertainties that we need to deal with. We have to leave no stone unturned. We’re just looking to make sure our customers always have water.”

How much water can a reservoir really hold?

With its sophisticated sonar equipment, ‘Reservoir Dog’ presents a clearer picture of our water storage capacity.  

Jason Ellis, survey senior tech, conduct bathymetric survey on Cheesman Reservoir.

Jason Ellis, survey senior tech, conducts a bathymetric survey on Cheesman Reservoir.

By Kristi Delynko

With a likeness to Captain Nemo and his Nautilus submarine, Angelo Martinez expertly steers his vessel — known as “Reservoir Dog” — through Cheesman Reservoir. But unlike Nemo, survey supervisor Martinez doesn’t need a submarine to see what’s at the bottom. Denver Water uses bathymetric surveying, sonar and GPS technology to map the contours of the reservoir floor.

Like the Nautilus — depicted as ahead of its time in Jules Verne’s classic novel — Reservoir Dog houses some pretty sophisticated equipment. The department upgraded its survey instruments this year, allowing the team to more efficiently gather data with a more expansive sonar reach.

In a single day, surveyors can now gather up to 10 million data points — an increase of almost 9 million from previous technologies. This data must then be processed and analyzed. “It’s a lengthy process to work through all the data and ensure it’s accurate before bringing it into GIS software,” said Brad Geist, surveyor.

Angelo Martinez, survey supervisor, explains the remote station the team sets up to ensure a strong signal when Reservoir Dog is out on the water

Angelo Martinez, survey supervisor, explains the remote station the team sets up to ensure a strong signal when Reservoir Dog is out on the water.

Once analyzed, the information can be used by a variety of Denver Water departments, including engineering and planning.

The last time Denver Water surveyed the bottom of Cheesman was in 2013. That bathymetric survey showed evidence of the lasting damage from the 1996 Buffalo Creek Fire and 2002 Hayman Fire, when fires charred the land, creating sediment that washes into the reservoir when it rains.

“With the fires damaging the reservoir’s watershed, a large amount of sediment gets washed into the reservoir, which decreases the storage capacity over time,” Geist said. “The data we gather this year can be compared to 2013 to see how this sediment impacts capacity, and in which areas of the reservoir it tends to accumulate.”

As environmental variables change over time, Denver Water planners want to know exactly how much water the reservoirs can hold. Bathymetric surveying is one way to help plan for future storage.

“I’m not sure of any other water utility in Colorado doing bathymetric surveying at this level,” Geist said.

While no sea monsters have been spotted thus far, the team has made some interesting finds at the bottom of the reservoirs, including roads in Dillon Reservoir and an old railroad grade in Eleven Mile Canyon Reservoir.

Take a ride with Martinez on Reservoir Dog.

Reservoir Dog, ready for action, at Cheesman Reservoir.

Reservoir Dog, ready for action, at Cheesman Reservoir.

Searching for solutions to help trout keep their cool

Experiment aims to improve stream health in Fraser River Valley by releasing water intended for the Front Range.

By Jay Adams

 

The Fraser River Valley in Grand County is known for its scenic views, hiking, biking and fishing, but this summer the valley turned into a high-altitude laboratory for the second year of a landmark experiment.

After water temperatures rose in Ranch Creek — a popular trout-fishing stream in Grand County — Denver Water voluntarily released around 120 acre-feet (40 million gallons) of water into the creek instead of diverting it to customers on the Front Range.

In early August, Denver Water released an additional 40-million gallons of water from its diversions into Ranch Creek over a 10-day span.

Over a 10-day span in early August, Denver Water released an additional 40 million gallons of water into Ranch Creek instead of diverting the water to the Front Range.

The 10-day experiment in August was part of Learning By Doing — a new partnership between Denver Water, Northern Water, Grand County, Trout Unlimited, Colorado Parks and Wildlife, and West Slope water groups devoted to protecting the rivers and streams of Grand County.

“We want to see what happens to the stream temperature when we release more water into the creek,” said Travis Bray, Denver Water environmental scientist. “We want to know if extra water makes a difference in temperature and how much water it takes to make a difference.”

Cold water temperatures are critical to sustaining a healthy trout fishery, which is why the Learning By Doing partners are searching for ways to keep water in Grand County streams cool during the warm summer months.

“The most vulnerable streams are on the valley floor,” said Kirk Klancke, president of the Colorado River Headwaters Chapter of Trout Unlimited. “That’s where the streams flatten out, slow down and heat up.”

As part of the experiment, Denver Water measured the stream flow, stream temperature and air temperature to determine the correlation between all three. Other factors that will be evaluated in the study include shade, land use, humidity, solar radiation, wind speed and rainfall.

“We can’t change the weather, but Learning By Doing is helping us find opportunities on both sides of the divide that can make a difference in the health of the rivers,” Bray said.

Denver Water started diverting water from Grand County in the 1930s and currently collects water from 36 streams in Grand County to store in Gross Reservoir for Front Range customers.

Learning By Doing ran a stream flow experiment when Ranch Creek warmed up this summer.

“In the past, we haven’t taken many steps to offset the environmental impacts we cause in Grand County,” Bray said. “With this experiment and through Learning By Doing, we’re changing that.”

Results of the experiment will be used to manage the streams in Grand County after the Gross Reservoir Expansion Project is approved and built.

Part of the expansion plan includes Denver Water’s agreement to release 1,000 acre-feet of water (about 326 million gallons) into Grand County streams each year strictly to help the environment. This is water that would have been diverted to the Front Range.

“The environmental pool is one of the greatest gifts Denver Water could give to our rivers and that’s why this experiment is so important,” Klancke said. “The scientific data will tell us the best way to distribute the pool water across the Fraser Valley so it can benefit as many streams as possible.”

The Learning By Doing team will decide how to use the environmental water with the assistance of Denver Water. “We’re looking for opportunities to collect water in a way that has as little environmental impact as possible,” Bray said.

Results from the Ranch Creek experiment are expected next spring. The Learning By Doing team is already planning additional experiments and projects.

“This experiment is what Learning By Doing is all about,” Klancke said. “We’re now looking at problems and truly learning how to fix them by doing something about it.”

Preparing Denver for multiple futures, not just one

Water planners must account for potential changes in climate, population, the economy and other variables.

By Kristi Delynko

Not everyone is Marty McFly, making the job of a Denver Water planner a difficult one.

We can’t time travel like Marty, though it would sure make it much easier to be a Denver Water planner.

Have you ever wished you could hop in your silver DeLorean with Marty McFly and Doc Brown and travel through time, like in Back to the Future?

For a Denver Water planner, the ability to zip back and forth across decades would certainly make the job of predicting future water demand much easier. “Try telling a planner he can’t predict the future — it’s a hard reality for us to accept,” said Greg Fisher, manager of demand planning. “But the fact is, no one can predict the future with absolute certainty, so we have to be ready for a variety of scenarios.”

Planning is a continuous process at Denver Water, and while we don’t budget for flying Deloreans, our water planners do employ some forward-thinking tactics to ensure we can deliver enough water to a growing population.

“Gone are the days when you could write a formal plan every few years, based on a linear planning process,” said Sarah Dominick, water resources engineer. “In the past, we would predict population growth and then correlate that with a straight, upward line to show future water demands.”

Today, new variables, such as climate change, demand a more flexible, comprehensive planning process, using a methodology that imagines several possible futures, not just one.

It’s called scenario planning — a type of adaptation planning — to study water supply requirements 50 years into the future. In addition to planning for things like population growth and decline, our planners also consider climate change, economic factors and government regulations to develop a number of possible futures. This makes it easier to adjust when conditions actually change.

Take climate change. The National Climate Assessment suggests climate change may be to blame for water shortages in the Southwest.

Among many other possibilities, Denver Water is exploring how Aquifer Storage and Recovery may contribute to delivering high-quality drinking water to our customers far into the future.

Among many other possibilities, Denver Water is exploring how Aquifer Storage and Recovery may fit in future planning efforts.

“The Southwest is warming, which will result in overall drier conditions. Unfortunately, we don’t know how precipitation will change in the future, but we know our water supply is very sensitive to warming,” said Laurna Kaatz, climate program manager. “Planning for multiple futures enables us to prepare for these types of unknowns.”

The planners monitor long-term climate trends and are always looking for innovative projects and new technologies that can improve efficiency, encourage reuse and increase the water supply.

“Having the flexibility to move water throughout our system, increase water storage capacities and build redundancy into our system, allows us to be prepared for whatever Mother Nature throws our way,” Dominick said.

Preparing for various scenarios also helps Denver Water invests wisely in its infrastructure, said CEO Jim Lochhead. “That ensures we build the right project, at the right time, and at the right cost,” he said. “Effective scenario planning means we are able to be financially responsible, while also making sure we have the appropriate facilities and resources to meet our customers’ water needs.”

5 things you may not know about Chatfield Reservoir

This popular recreation spot also happens to be one of Colorado’s hardest-working bodies of water.

By Jessica Mahaffey

Are you a Chatfield junky?

As a long-time Littleton resident, I have fond memories of sailing, water skiing, swimming, fishing and camping at the reservoir with friends on my summer breaks from nearby Columbine High School (Rebel Pride!).

Today, I still enjoy afternoon walks on my favorite trails and take my two small dogs to the onsite dog park.

I’m hardly alone. Chatfield State Park is summer sanctuary in Denver’s back yard, welcoming more than 1.5 million visitors each year, according to Colorado State Parks.

The result: Nearly $10 million in economic impact to the communities within 50 miles of the park.

With all the pleasure it provides, many people may not realize that this is one hard-working reservoir, handling multiple duties and obligations. Here are five facts about Chatfield you probably don’t know:

album-101-21-south-platte-flood

Photo of the South Platte River flood of June 1965, looking due east.

  1. Chatfield was built for flood-control — not to store public drinking water.

It was built in 1967 by the U.S. Army Corps of Engineers in response to the 1965 flood of the South Platte River that cost more than $500 million and claimed 28 lives.

This reservoir can hold more than 350,000 acre-feet of flood water in emergency situations, but its current capacity is only 27,000 acre-feet of water, the equivalent of 8.8 billion gallons.

During drought conditions, water can be pumped from Chatfield to Marston treatment plant to supplement Denver’s public drinking water supply.

  1. Even though we don’t own or operate the reservoir, only water from Denver Water is currently stored behind the dam.

The U.S. Army Corps of Engineers owns Chatfield and leases the land to Colorado State Parks, which oversees day-to-day operations at Chatfield State Park.

Under a state agreement, Denver Water can fill Chatfield Reservoir with water, as long as we maintain water levels for community recreation.

  1. The water stored in Chatfield is used for water exchanges.

Think of an exchange reservoir as a bank. The water we “deposit” (store) at Chatfield can be used to “pay” (trade) downstream users with rights to the water, instead of sending it from our upstream reservoirs that supply Denver’s drinking water. This allows us to keep water higher in our reservoir system and to later deliver it by gravity to our water treatment plants.

  1. Chatfield provides recreational benefits beyond the obvious.

    Bypass flows released from Strontia Springs Reservoir located at the top of Waterton Canyon keep the river at optimum levels, sustaining a healthy trout fishery for anglers like the author’s brother Jason Kirk, pictured here.

    Bypass flows released through Waterton Canyon sustain a healthy trout fishery for anglers like the author’s brother Jason Kirk, pictured here.

In addition to preserving water levels for recreation, Denver Water uses its space in Chatfield to capture water it releases from Strontia Springs Reservoir, located a few miles upstream of Chatfield. These so-called “bypass flows” keep the river at optimum levels all year long, supporting the trout fishery in Waterton Canyon.

  1. Chatfield is about to take on even more responsibility.

The Army Corps of Engineers recently approved the Chatfield Storage Reallocation Project.  The project will increase water levels at the reservoir by about 12 feet, which is about 20,000 additional acre-feet, or about 6.5 billion gallons.

But this won’t be Denver’s water. Instead, it will help meet the water demands of growing populations in Centennial, Castle Rock, Castle Pines and other Front Range communities. It will also be used by farmers downstream of Denver. Denver Water will still maintain its original storage pool of more than 27,000 acre-feet and will remain involved in the overall operation of Chatfield after the reallocation is completed.

But that’s not all. The Chatfield Reservoir Mitigation CompanyColorado Parks and Wildlife and the Colorado Water Conservation Board are developing a plan for an environmental pool to provide up to 1,600 acre-feet of storage. But there is room for more. Learn more about Denver Water and The Greenway Foundation’s effort to provide more water for fishing, farmers and fun on the South Platte: Not your average pledge drive.

So whether you are a Chatfield regular like me or someone who simply enjoys driving by it from time to time, I hope knowing more about Chatfield Reservoir increases your appreciation for this metro-area amenity.

Chatfield Reservoir can hold more than 350,000 acre-feet of flood water in emergency situations, but its current capacity is only 27,000 acre-feet of water, the equivalent of 8.8 billion gallons.

The water levels at Chatfield Reservoir will increase by about 12 feet, which is about 20,000 additional acre-feet, or about 6.5 billion gallons.

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