Tag: Colorado River

Colorado River Delta still benefiting from flood experiment

Colorado River delta
The Colorado River Delta captured in a 2004 image from the International Space Station. Via NASA Earth Observatory.

Monitoring report documents renewed life

Staff Report

In just two years following a man-made flood in the Colorado River Delta, cottonwoods and willows have grown 10 feet tall, rebuilding habitat for other native plants and animals, according to a new monitoring report on the international experiment to re-water the long-arched region.

“This short-term event has had lasting consequences. This really demonstrates that a little bit of water does a lot of environmental good,” said Karl W. Flessa,  professor of geosciences at the University of Arizona. Continue reading “Colorado River Delta still benefiting from flood experiment”

Will global warming boost groundwater supplies in the Upper Colorado River Basin?

Some climate models project more rainfall in the West

A bend in the Yampa River near Dinosaur National Monument in northwest Colorado.
Will global warming boost flows in Colorado River tributaries? @bberwyn photo.

Staff Report

While most recent research suggests that the Colorado River will be depleted well beyond current demands as global temperatures increase, there may be one small bright spot on the horizon. Even if runoff from snow declines, groundwater replenishment in the basin may hold stead under projected increases in  precipitation, the U.S. Geological Survey and U.S. Bureau of Reclamation found in a new study.

“You can’t manage what you don’t measure,” said Fred Tillman, lead author and USGS scientist. “These results are the first step in understanding the quantity of groundwater we can expect in the Upper Colorado River Basin; however, further studies are needed to help more accurately forecast future groundwater availability.”

The Colorado River is a critically important source of water for more than 35 million people in the United States and 3 million people in Mexico. As much as half the water flowing in the rivers and streams in the Upper Colorado River Basin originates as groundwater. Understanding how much groundwater is available and how it’s replenished is important to sustainably manage both groundwater and surface water supplies in the Colorado River basin now and in the future.

In the new study, USGS and Reclamation scientists estimated projected changes in groundwater recharge for the Upper Colorado River Basin from recent historical (1950–2015) through future (2016–2099) time periods using climate projections and a groundwater-recharge model.

Simulated future groundwater recharge through 2099 is generally expected to be somewhat greater than the historical average in most decades due to an anticipated wetter future climate in the basin under the most advanced climate modeling projections. Groundwater resources are replenished through increases in precipitation, which may offset reductions from increased temperatures. The full report is available online in the journal Geophysical Research Letters.

But researchers urged caution interpreting the results because a few of the models suggested  decreased future recharge relative to the historical climate period.

Continue reading “Will global warming boost groundwater supplies in the Upper Colorado River Basin?”

Colorado River pulse flow released surge of greenhouse gases

New growth in delta could offset CO2 released from riverbed

Colorado River delta
The Colorado River Delta captured in a 2004 image from the International Space Station. Via NASA Earth Observatory.
Our special series on the Upper Colorado River is made possible with support from the Colorado River Water Conservation District. Contact Summit Voice for other sponsorship opportunities and click on the banner to visit the river district online.
Supported by the Colorado River District.

Staff Report

Human management of natural ecosystems always has unintended consequences, and the Colorado River is no exception. After decades of intense dam building and diversions, the mighty river is a mere shadow of it former self, reduced to a trickle in some places and polluted by return flows in others. Along its entire length, ecosystems, including riparian zones and native fish, have suffered, with some of the biggest impacts in the Colorado River delta.

In an effort to restore at least some key reaches of the river, scientists and water managers have teamed up to try mimic some of the Colorado’s natural functions, with controlled releases of water to build up beaches. Those efforts culminated in early 2014 during an eight-week experiment that unleashed a mighty torrent of water from Morelos dam (on the border with Mexico and the USA).

The huge surge (130 million cubic metres) of water raised river levels down to the delta, which has been starved of water for decades. Scientists closely monitored how the release — and potential future releases — affect agricultural crops and natural plant and animal life of the lower delta.

But the pulse flow had another side effect. As the water washed over earth and rocks that had been dried out for many years, it dissolved carbon and sent a surge of greenhouse gases into the atmosphere. Continue reading “Colorado River pulse flow released surge of greenhouse gases”

Colorado Parks and Wildlife targets illegally stocked pike in Green Mountain Reservoir with a bounty for anglers

Northern pike
Colorado Parks and Wildlife is offering a $20 bounty for northern pike caught in Green Mountain Reservoir. Photo courtesy CPW.

Non-native predators could threaten endangered species in Colorado River

Staff Report

Colorado wildlife managers will try to curb expansion of non-native northern pike in Summit County’s Green Mountain Reservoir by paying anglers a $20 bounty for each fish they deliver to the Heeney Marina.

The illegally introduced fish are taking a toll on trout in the reservoir north of Silverthorne and could escape to the Blue River and make their way to the Colorado River. That could add to the challenges of trying to recover four endangered native Colorado River fish species, according to Colorado Parks and Wildlife.

“The (pike) were dumped in there several years ago by someone who selfishly didn’t consider the serious consequences we are now dealing with,” said CPW aquatic biologist Jon Ewert. “People should know that illicit stocking is a problem not only for ethical reasons but legal reasons as well. Anyone caught doing it faces severe penalties.” Continue reading “Colorado Parks and Wildlife targets illegally stocked pike in Green Mountain Reservoir with a bounty for anglers”

Groundwater a huge factor in sustaining Colorado River flows

New study helps resource managers plan for climate change

Evening clouds along the Yampa River in northwestern Colorado.
Groundwater is a huge factor in assessing climate change impacts on the Colorado River. @bberwyn photo.
kn
Resource managers need as much information as possible about Colorado River flows to make sustainable management decisions.

Staff Report

Resource managers grappling with the vexing question of how to allocate Colorado River water to the thirsty cities, ranches and farms of the Southwest have some new food for thought. A new U.S. Geological Survey study published this week in the journal Water Resources Research shows that more than half the streamflow in Upper Colorado River Basin originates as groundwater.

The information is especially important in the context of how climate change — through increased temperatures and evaporation, as well as changing precipitation patterns — will affect the river. One recent study, for example, showed that warmer spring temperatures are reducing flows independently of winter precipitation. In 2014, another study found that groundwater depletion threatens the sustainability of the Colorado River. Continue reading “Groundwater a huge factor in sustaining Colorado River flows”

April storms boost Colorado snowpack

Much of West reports record-fast meltdown under El Niño heat

Colorado snowpack May 1 2016
April storms boosted Colorado’s snowpack, with near average runoff and river flows expected during the spring and summer in most parts of the state.
Colorado snowpack map
Southern parts of Colorado have not had above average snowpack readings for several years in a row, which could be part of the “new normal” in the global warming era

Staff Report

April storms helped boost Colorado’s statewide snowpack to above average, but two river basins in the southern part of the state continue to report below normal readings.

The state’s mountain areas benefited the most from a series of wet, El Niño-fueled storms, bringing precipitation for the water year to average, according to Brian Domonkos, the Colorado snow survey supervisor for the USDA Natural Resources conservation service.

“At this time last year the water supply outlook was grim at best,” Domonkos said. “Colorado’s current snowpack and precipitation levels are right where we want to be this time of year. Elsewhere in the Western United States seasonal snowpack during 2016 succumbed to early spring warming and did not recover as Colorado did from recent storms,” he added. Continue reading “April storms boost Colorado snowpack”

Climate: Snowpack dwindles across southern Colorado

‘Every El Niño is different’

western precipitation map 2016
Precipitation across the West has been patchy for the water year to-date.

Staff Report

March snowfall across the Colorado mountains helped maintain the statewide snowpack near average for the water year to-date, but the strong El Niño hasn’t played out as expected.

Instead of boosting moisture in the southwestern corner of Colorado, this year’s edition of the Pacific Ocean warm-water cycle sent the storm track surging into the Pacific Northwest and then down across Colorado’s northern mountains. Northeastern Colorado has been the wettest of all, with a wide section of the plains seeing up to double the average annual rainfall so far.

That’s bad news for the Southwest, where moisture has been sparse for the past several years. Western New Mexico, most of Arizona and the southern California deserts and coast have been especially dry since the start of the rainy season. Regionally, snowpack in the Colorado River Basin above Lake Powell was 94 percent of average as of March 17, and the Federal Bureau of Reclamation is projecting that the inflow to Lake Powell will be just 80 percent of average for the April to July period. Continue reading “Climate: Snowpack dwindles across southern Colorado”