While I was raised in Littleton, I grew up hearing stories from my family about their farm. They were farmers and ranchers along Bear Creek until their land was taken under eminent domain for the Bear Creek Reservoir. I have a hard time picturing an agricultural community in an area that is now suburbs, golf courses, and a park. To create a metropolitan area like Denver, the landscape has changed completely and will continue to change. Today, many other communities are concerned how much longer their way of life can persist in the wake of such change.
By 2050, Colorado’s population will almost double to 10 million, bringing with it a water shortage of more than 500,000 acre feet per year. Municipalities will look to agricultural water as a source of supply. In that same timeframe, the irrigated acreage in the South Platte Basin may decrease by…
Since March, Denver Water has replaced more than 260 lead service lines found during our construction work.
By Jay Adams
The Postal Service delivers mail to your mailbox. The power company sends electricity to your meter. And Denver Water provides safe drinking water to your service line, which connects our water main to your home.
Denver Water foreman, Johnny Roybal, overlooks Steve Foster (left) and Daniel Ruvalcaba as they work to replace a lead service line.
Wherever your outdoor adventures take you, being mindful of snakes, bears and other animals is a must.
Read and follow the signs, like the one pictured here, throughout Waterton Canyon to learn how to safely interact with the wildlife.
By Tyler St. John
With a footprint larger than Rhode Island and Delaware combined, the opportunities to experience and observe wildlife in its most natural form are vast at Yellowstone National Park.
But as Public News Service story recently explained, park officials are shifting their focus from the 67 species of mammals that call this park home to the 68th found in this park every single day — humans.
Ryan Atwell, the park’s new social science coordinator, described the challenges his team faces with social media. “Every other person seems to be taking a selfie, or looking at a phone instead of watching where they’re walking,” he told Public News…
Here’s an interview with Audubon’s new Colorado River Project director, Jennifer Pitt, from Xander Zellner writing for the Audubon website. Here’s an excerpt:
Over the past century, the dams and diversions built to support the explosive growth of cities and agriculture in the American West have left the once-mighty Colorado River a shadow of its former self. The river, which once flowed straight to the Gulf of California, and through parts of Mexico, is now fully allocated for human use, and dries up some 100 miles short of the sea, disrupting the riparian ecosystems along the river’s banks. With climate change promising to make water an even scarcer commodity, it’s more important than ever that water-management plans in the West take the health of the river and the wildlife it supports into account.
That’s where Jennifer Pitt, the National Audubon Society’s new Colorado River project director, comes in. Before joining Audubon last winter, Pitt spent 17 years working on Colorado River projects for the Environmental Defense Fund, including taking part in the negotiations for Minute 319, an historic water-sharing agreement between the United States and Mexico. Through that treaty, conservationists were able to secure a delivery of 34 billion gallons water to the Colorado River Delta; that release of water allowed the Colorado River to flow all the way to the Gulf of California for the first time in decades, providing a desperately needed shot of hydration to the delta’s ecosystems. In her role at Audubon, Pitt is working on the negotiations for the second iteration of the Minute 319 agreement, in addition to increasing Audubon’s role in western water policy to ensure the Colorado River is used to support both people and wildlife.
Pitt spoke with Audubon about how she’s hoping to change the future of the Colorado River, and why the moment is ripe for productive partnerships between conservationists and other Colorado River stakeholders.
Audubon: Why are we at a such a critical moment for the Colorado River?
Jennifer Pitt: There is no excess water in the Colorado River; it’s all been over-allocated. From a water supply perspective, or water user’s perspective, the fact that demand now exceeds supply is the big story. The reservoirs are 50 percent empty right now—as an average—and in the last 15 years of drought, instead of reducing uses, we’ve been emptying what’s in storage. And we can’t do that forever, obviously.
A: What’s been the impact on wildlife that depends on the river?
JP: Eighty percent of the water in the Colorado River starts out as snow: It snows in the mountains and then over the late spring and summer, that snow begins to melt and it flows into headwater creeks and flows downstream and into the bigger rivers, eventually flowing all the way down to the Upper Gulf of California. The riparian forests—the cottonwoods and willows—evolved along with these big spring and summer floods. For those trees to grow or reproduce, they need to have floods that get onto the river bank. That’s how you sustain healthy riparian forests over time.
But that water cycle has been quite altered by the extensive building of reservoir storage on this river and by all the diversions. From the bird’s-eye view, there’s been a loss of the healthy riparian forests extensively through the entire watershed.
In the Colorado River Delta, the environmental impact of the imbalance between supply and demand has been quite extreme. The delta was North America’s most significant desert estuary—380 bird species have used the habitat in the delta. Remnant wetlands in the region support 70 percent of the entire population of the Yuma Ridgeway’s Rail, an endangered bird. But until the Minute 319 treaty in 2012, the delta had been decimated.
A: How do we ensure that in the midst of this water crisis, wildlife and their habitats get their due?
JP: A couple of decades ago, the conservation community on its own had all these ideas about how to change water management to be more in line with what we need for healthy rivers to support fish and wildlife. And we weren’t making a lot of progress, because water users had a management system that was working for them.
We’re now in a moment where everything is not working for the water users. The water stored in Colorado River reservoirs is declining nearly every year, and we’re witnessing an extended drought. Climate change is already decreasing water availability in this region, and over the next several decades we’ll see the impact of those reduced flows playing out to an even greater degree. On top of that, more and more people continue to move into this region.
Water users and managers across this region have been forced to a day of reckoning; they have to take a fresh look at how water is managed and used in this region. And as they’re doing that, Audubon has an opportunity to come to the table to look for places where river and water management can align better with what we need to sustain healthy habitats for birds and wildlife.
A: Why has the existing legal framework been so challenging to work with?
JP: Let me take you back to the first European settlers who moved out to this region to mine. There was a gold rush here around 1859 and in order to do the mining they needed a water supply. Some guy went up to the mountains and he diverts the creek so he has a flow going through. So he’s got his mine up and running and he’s getting gold and getting rich. The next spring, some other dude comes and claims a mining claim further up the mountain. Now the first guy who was there, his water dries out because the guy uphill from him is diverting the water. It’s on that settlement pattern that the one of the fundamentals of water management was established—and it’s called the Doctrine of Prior Appropriations: The first person who diverted the water has the most senior right and the new guy is not allowed to take water until the first person gets all of their water.
A: Is this system outdated?
JP: It’s just the way it is. There’s not going to be a revolution; we’re not trying to wipe the legal system clean and start over from scratch. Thousands of people own water rights, and this is the United States of America, so we’re not going to seize their property. So the question is, how can you—within the constraints of this existing system—build policies and programs and investments and infrastructure that meet 21st century water needs? The fundamental thing we need to ensure is that we’re taking care of our rivers is to include river health as one factor when making decisions.
A: What’s the big project on your plate right now?
JP: Minute 319 expires in 2017, and at the moment, the United States and Mexico are engaged in figuring out the next agreement. They don’t want to just let the agreement expire; they want a new version, which might be exactly the same or it might be modified. I’m working on trying to make sure that that agreement has solid components that ensure that the water deliveries go to environmental purposes. And I’m also working on making sure that we’re implementing the existing commitments to flows and dollars in restoration [for the existing agreement].
Global warming will take a toll on reptiles and birds in the Southwest. @bberwyn photo.
Many bird species could lose between 78 and 85 percent of their existing habitat
Birds and reptiles in the Southwest that live in fragmented habitat will be hit hardest by global warming in the decades ahead, according to a new study by scientists with the U.S. Geological Survey and the Northern Arizona University.
The researchers took a close look at about 30 different animals, including well-known species such as the Gila monster, horned lizard, chuckwalla, Sonoran desert tortoise, pinyon jay, pygmy nuthatch, sage thrasher and black-throated sparrow.
A few species could see their habitat expand as the climate warms, but many others will be hit hard by global warming. Most climate models project temperatures to increase by about 6 degrees Fahrenheit in the Southwest in the next century, while precipitation is expected…
KREMMLING – Denver Water has taken steps to distance itself from a recent risk assessment of Ritschard Dam, which forms Wolford Reservoir five miles north of Kremmling.
The 21-year-old dam has found to be moving slightly and settling more than normal and a risk analysis workshop was held in February by a group of experts assembled by the Colorado River District, which owns the dam and reservoir.
After the risk workshop John Currier, the chief engineer for the River District, wrote a memo to the district’s board saying “a key conclusion” of a consultant review board is that “the dam is safe” and “there is no need for immediate action.”
Currier also wrote in his April 7 memo that the “key parties and participants” in the February risk workshop “included 1) the State Dam Safety Branch, 2) Denver Water, 3) our consultant review board, 4) our engineer, AECOM and 5) River District staff.”
But on May 2, Robert Mahoney, the director of engineering for Denver Water, sent Currier a letter critical of his April memo.
“In the memorandum, you characterize Denver Water as a ‘risk estimator’ and an active participant during the workshop,” Mahoney wrote. “Denver Water takes exception to these characterizations. At no time did Denver Water participate in the workshop as a risk estimator, nor was it ever invited to participate as a risk estimator on the panel.”
Mahoney also said that Denver Water “disagrees with characterizations in the memorandum implying that Denver Water was an active participant and that we concluded and agreed with the findings of the risk estimators. Denver Water’s role in attending the workshop was that of a concerned observer.”
Currier included the letter from Denver Water in a July 7 memo to the River District board. The memo and the letter were made public this week when the public agenda was released for the district’s July 20 board meeting in Glenwood Springs.
Mahoney raised other concerns in his letter as well.
“Based on our observations, the workshop and your memorandum only addressed the probability of a dam failure consequence,” Mahoney wrote. “While the probability of a dam failure appears low, dam failure is not the only potential adverse impact of concern to Denver Water. The probability of cracking in the core of the dam, which could reduce storage capacity, has a much greater range of uncertainty.”
Denver Water currently leases 40 percent of the water in Wolford Reservoir from the River District.
The reservoir can store 66,000 acre-feet of water and on July 14 the dam was holding back 65,240 acre-feet.
When its lease expires at the end of 2020, Denver Water is slated to become a part owner of the water in the reservoir.
“The River District will convey ownership, use and control of 40 percent of storage space and water right in Wolford Reservoir to Denver Water,” according to Jimmy Luthye, a communications specialist with Denver Water who checked Friday on the status of Denver Water’s stake in the facility.
As Jim Pokrandt, director of community affairs at the Colorado River District put it on Friday, “Denver Water currently holds a 40 percent lease. After 2019, it will be a 40 percent owner.”
Dam has issues
In his letter, Mahoney also suggested that developing a plan to fix the dam would be “beneficial.”
“According to Mr. Dick Davidson (of AECOM), cracking of the core has a 50 percent annual probability of occurrence starting in 20 years (the time criteria set for the workshop and probability estimation),” Mahoney wrote. “Given this uncertainty, it would be beneficial to develop plans now to remediate Ritschard Dam in the event of a crack.
“Further, based on the information presented at the workshop, Denver Water does not agree that Ritschard Dam is functioning as designed because no dam is designed to function with the degree of movement observed at Ritschard Dam to date.
“As addressed in the April 27, 2016 letter from Bill McCormick, chief of the Dam Safety Branch of the state engineer’s office, Ritschard Dam is in the category ‘of dams with significant issues’ and is on ‘an abnormal trend,'” Mahoney wrote.
Ritschard Dam is 122 feet tall, 1,910 feet wide, and sits across Muddy Creek, which flows into the Colorado River east of Gore Canyon. It was built for the River District in 1995 at a cost of $42 million by D.H. Blattner and Sons of Minnesota.
The dam has an impermeable clay core that is covered on both the upstream and downstream sides with rock fill, including shale rock excavated on site during construction.
In 2008, engineers working for the river district noticed the dam had settled downward by a foot-and-a-half, instead of the expected normal settling of one foot.
They decided to install monitoring equipment, including inclinometers, which measure slope angles.
Engineers for the river district have since installed an increasingly sophisticated array of monitoring devices. And they’ve verified that the dam has settled over 2 feet downward.
The dam has also moved horizontally, by 8 inches, at a location about 40 to 50 feet from the top of the dam.
Mike May, an engineer with AECOM, told the river district board in January 2015 that because of “poorly compacted rock fill,” the dam’s rocky outer shells are still moving, especially the downstream shell, and that the clay core of the dam, which is somewhat elastic, is also moving.
While the dam does not have “a global stability problem,” May said the concern is that if enough movement occurs, it could cause cracks in the clay core.
Water could then find its way into those cracks, start transporting material and widening the cracks, and the dam could eventually be at risk of failing.
McCormick, in his April 27 letter referenced by Mahoney, also included Denver Water as part of the risk assessment group.
“At the conclusion of the meeting it was the opinion of the participants, CRD, AECOM, risk analysis consultants John Smart and Larry Von Thun, Colorado Dam Safety and Denver Water that the risk of sudden failure of the dam by any of the failure modes analyzed was remote,” McCormick wrote. “It was also agreed that given that determination the need to continue to actively pursue physical modifications to the dam was not warranted at this time.”
McCormick also said that the results of the risk analysis session “now allow the Colorado River District and Colorado Dam Safety Branch to return to more normal reservoir operations with confidence that public safety is not being compromised.”
However, McCormick also noted that “due to the remaining uncertainty of the deformation behavior we agreed that Ritschard can only be classified as ‘conditionally satisfactory’ and that continuing action with respect to monitoring and observations is required by Colorado River District to operate the reservoir as planned.”
In his letter, McCormick cited a presentation at the risk workshop by Dr. Gavin Hunter, a professor at the University of New South Wales who has researched deformation behavior in 130 embankment dams.
Gavin compared the magnitude of the settlement observed at Ritschard dam with other dams in his data set.
“The displacement observed at Ritschard exceeds the majority of the dams studied, with only half the available data,” McCormick wrote. “Dr. Hunter describes this as ‘an abnormal trend.'”
McCormick also noted that Gavin’s research on the amount of settlement at Ritschard put it in the “region of dams with significant issues” category.
As such, McCormick said the River District should develop a plan for remediation work on the dam.
“We would encourage the Colorado River District to fully appreciate the abnormal and as yet not fully understood behavior of Ritschard dam and put an appropriate timeline on the ‘foreseeable future,’ McCormick wrote. “Based on the analyses done to date one could reasonably anticipate that remediation work will be necessary at some point in the future. We strongly encourage the Colorado River District to continue to plan for such remediation to avoid undue pressure on the operation of that facility as might be caused by a sudden change in the dam’s performance.”
McCormick said Friday that a workshop to develop an “action plan” has been set for the third week of August.
In his April 4 memo, Currier of the River District had written that the district’s analysis indicated that risk of failure of the dam from deformation was 1 in 100 million, while the risk of the dam failing by a “probable maximum flood” causing overtopping – a standard measure of risk – was one in a million.
He also explained why monitoring the dam’s movement was a better approach than trying to stop the dam from moving.
“With the dam failure risk so low, even with twice the current deformation, the estimators concluded that there is really no compelling technical or health, safety and welfare reason to embark on a remediation plan,” Currier wrote. “In fact, from a ‘do no harm’ perspective continued monitoring is equally if not more preferable to active remediation.
“While remediation might put to rest some nagging uneasiness about on-going deformation and when it might end, there is no absolute certainty that it would or should allay that uneasiness.
“In essence, remediation might replace one known uncertainty with a new, unknown, uncertainty. All dam owners are faced with some level of future uncertainty, we just happen to be keenly aware of it by virtue of extensive monitoring and investigation,” Currier wrote.
And in his July 7 memo sent to the River District board, Currier said an additional inclinometer has recently been installed at the toe of the dam to track movement, and that he would be sending Mahoney of Denver Water “a short response clarifying a few matters and inviting Denver’s continued involvement and expertise in the deformation issues.”