Posts Tagged ‘aquifer storage and recovery’

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.”

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.”

They’re coming. Will we have enough water?

More people, record-low demand; What’s going on?

By Jay Adams

Construction cranes fill the Denver skyline, a sign of the city's growing population.

Construction cranes fill the Denver skyline; a sign of the city’s growing population.

Could it be our beloved Broncos? Maybe it’s the great skiing in the mountains, the 300 days of sunshine or perhaps even our new marijuana laws. Whatever the case, Colorado’s population is booming.

The Denver Post reports that more than 100,000 people moved to Colorado from July 2014 through July 2015 — the second-highest population percentage increase of any state in the country, after North Dakota. Colorado’s state demographer, Elizabeth Garner, predicts the state’s population could rise by another 100,000 this year, according to the article.

Whatever their reasons, this much is clear: With all those new people, the pressures on our water system are bigger than ever.

“We don’t know what’s going to happen down the road, but as a water provider, we need to be prepared for a number of different scenarios,” said Greg Fisher, Denver Water manager of demand planning.

Water planning used to be more straightforward, Fisher said. “In the past, planners relied on historical weather and consumption data and paired it with population projections to estimate demand. It’s a little more complicated today.”

Drought in 2013 led to low water levels at Dillon Reservoir in 2013.

Drought conditions in 2013 led to low water levels at Dillon Reservoir.

Planners have to prepare not just for population growth, but also climate change, economic variability, changes in environmental attitudes, changes in water-use patterns, government regulations, new industries, droughts and other factors, Fisher said.

Each of those factors are interconnected, and each play a role in our long-term water planning, he said.

Last year was a perfect example of why it’s so difficult to predict future water consumption. According to Denver Water records, 2015 was our lowest demand for water since 1970, despite a population increase of 400,000 people. We also saw wild weather swings, with record-high precipitation for the entire watering season, followed by the warmest September in Denver Water’s records.

With half a million more people expected in the metro area by 2040, planners are taking an “all-in” approach that includes conservation, water reuse and development of new water supplies.

Here are examples of the strategy:

In conservation, Denver Water is constantly looking at ways to help our customers use water efficiently, said Jeff Tejral, manager of water conservation. After the 2002-2004 drought, Denver Water set a 10-year goal of cutting water use 22 percent from 2007 through the end of 2016. The average use since 2009 has met that conservation goal, and we continue to ensure that level is permanent.

DSC_0042

Denver Water employees spend the summer educating customers about efficient watering.

“Our customers have been doing a great job,” Tejral said. “We’ll keep working with them to maintain that level of savings and always strive for more.” Denver Water’s Conservation staff helps customers become more efficient by offering rebates on water-saving fixtures, fixing leaks and educating customers about water-smart lifestyles.

In terms of reuse, Denver Water produces an average of 2 billion gallons of recycled water each year, which is treated wastewater used for irrigation and industrial uses. Using recycled water reduces the demand on potable (drinking) water and helps keep more water in mountain streams.

Denver Water is seeking a permit to enlarge Gross Dam in Boulder County.

Denver Water is seeking a permit to enlarge Gross Dam in Boulder County.

For new supplies and storage, we continue to seek a permit to expand Gross Reservoir in Boulder County, and develop gravel pits in Adams and Weld counties for additional water storage. We’re even exploring the feasibility of storing water in underground aquifers.

“Planning for the water demands of tomorrow requires constant innovation and an understanding of how customer needs are changing,” Fisher said. “We always need to be thinking about the future and even challenge major assumptions.”

 

What lies beneath? (We’re about to find out)

Denver Water looks 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.

In the next month, Denver Water is drilling 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.

Bob Peters, water resource engineer at Denver Water, has spent the last two years planning the ASR test.

Bob Peters, water resource engineer at Denver Water, has spent the last two years planning the ASR test.

“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.”

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 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.

The drilling tests are needed to determine the water-bearing and storage capacity of the rock in the Denver Basin.

The drilling tests are needed to determine the water-bearing and storage capacity of the rock in the Denver Basin.

There are two misconceptions about the big rigs people in Denver may see in the next month:

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, he 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.”

Results of the tests are expected by the end of 2015. The findings will help determine if Denver Water should build a pilot well, and determine the location and design. If results of the bore tests are promising, the pilot well could be operational by 2018.

“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.”

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