Category: rivers

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.
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Supported by the Colorado River District.

Staff Report

Human management of natural ecosystems always has unintended consequences, and the Colorado River is no example. 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”

Pharmaceutical pollution widespread in Southeast U.S. streams

Many streams are at risk from pharmaceutical pollution

Cumulative median concentrations of pharmaceutical chemicals detected during the sampling conducted in June of 2014 in 59 small streams. The four urban study areas are shown in boxes, with details in the study.
Cumulative median concentrations of pharmaceutical chemicals detected during the sampling conducted in June of 2014 in 59 small streams. The four urban study areas are shown in boxes, with details in the study. Via USGS.

Staff Report

Traces of pain-relieving substances, diabetes drugs and allergy medicines are widespread in small streams across the Southeast, especially in urban zones like Raleigh, North Carolina, the U.S. Geological Survey found in a new study.

The USGS in 2014 sampled 59 small streams in portions of Alabama, Georgia, North Carolina, South Carolina and Virginia for 108 different pharmaceutical compounds and detected one or more pharmaceuticals in all 59 streams. The average number of pharmaceuticals detected in the streams was six. Continue reading “Pharmaceutical pollution widespread in Southeast U.S. streams”

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.
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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”

Denver authorizes gray water program

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A new gray water program in Denver could help temper demand for new water development projects in Colorado. @bberwyn photo.

City takes big step toward more sustainable water use

Staff Report

Denver, Colorado took a big step toward meeting an ambitious 20 percent water conservation target by passing an ordinance authorizing the use of gray water for residential, commercial and industrial purposes. The city hopes to cut per capita use of potable water by 20 percent by 2020.

Enabling large water users like hotels, multi-family residential complexes and dormitories, as well as industrial facilities, to use gray water will not only help conserve a valuable resource, it will help those facilities save money. Continue reading “Denver authorizes gray water program”

Environment: Can dams be operated without killing rivers?

Glen Canyon Dam. Image courtesy NASA Earth Observatory.
Glen Canyon Dam. Image courtesy NASA Earth Observatory.

New study eyes impacts to aquatic insects

Staff Report

Using a vast sample of data collected in a citizen science project, researchers say they’ve been able to discern how hydropeaking affects aquatic insects that form the base of river food chains. The information could help resource managers develop alternative hydropower practices that aren’t as harmful to ecosystems, according to a new study published in the journal BioScience.

Hydropeaking refers to the practice of increasing river flows at times of peak demand, generally during the day. This study shows how abrupt water level changes affect aquatic insects in every stage of life. The research was done by scientists with the U.S. Geological Survey, Oregon State University, Utah State University and Idaho State University. Continue reading “Environment: Can dams be operated without killing rivers?”

Study says high mountain streams serve as ‘climate refuge’

There’s hope for coldwater fish in the West, especially if resource managers are able to plan and implement conservation measures

CDOW Aquatic biologist Jon Ewert holds a rainbow trout for measurement while sampling fish populations in the Blue River in Silverthorne, Colorado.
CDOW Aquatic biologist Jon Ewert holds a rainbow trout for measurement while sampling fish populations in the Blue River in Silverthorne, Colorado. @bberwyn photo.

Staff Report

Global warming is hitting the high mountain world especially hard, with records from recent decades showing temperatures above 13,000 feet increasing 75 percent faster than at lower elevations in some regions. But for a while at least, the high country may end up being a last-ditch climate refuge for many species, including cold-water fish.

A recent study suggests that water temperatures in mountain streams aren’t going up as fast as previously projected. That means there’s time to survey ecological communities and plan conservation strategies, according to a new study published in the Proceedings of the National Academy of Sciences. Continue reading “Study says high mountain streams serve as ‘climate refuge’”