Day: April 21, 2014

Combined impacts of current and future dust deposition and regional warming on #ColoradoRiver Basin snow dynamics and hydrology

Dust streaming across Four Corners April 29, 2009 via MODIS
Dust streaming across Four Corners April 29, 2009 via MODIS

Click here to read the abstract (J. S. Deems, T. H. Painter, J. J. Barsugli, J. Belnap, and B. Udall):

The Colorado River provides water to 40 million people in seven western states and two countries and to 5.5 million irrigated acres. The river has long been overallocated. Climate models project runoff losses of 5–20% from the basin by mid-21st century due to human-induced climate change. Recent work has shown that decreased snow albedo from anthropogenic dust loading to the CO mountains shortens the duration of snow cover by several weeks relative to conditions prior to western expansion of the US in the mid-1800s, and advances peak runoff at Lees Ferry, Arizona, by an average of 3 weeks. Increases in evapotranspiration from earlier exposure of soils and germination of plants have been estimated to decrease annual runoff by more than 1.0 billion cubic meters, or ~5% of the annual average. This prior work was based on observed dust loadings during 2005–2008; however, 2009 and 2010 saw unprecedented levels of dust loading on snowpacks in the Upper Colorado River Basin (UCRB), being on the order of 5 times the 2005–2008 loading. Building on our prior work, we developed a new snow albedo decay parameterization based on observations in 2009/10 to mimic the radiative forcing of extreme dust deposition. We convolve low, moderate, and extreme dust/snow albedos with both historic climate forcing and two future climate scenarios via a delta method perturbation of historic records. Compared to moderate dust, extreme dust absorbs 2× to 4× the solar radiation, and shifts peak snowmelt an additional 3 weeks earlier to a total of 6 weeks earlier than pre-disturbance. The extreme dust scenario reduces annual flow volume an additional 1% (6% compared to pre-disturbance), a smaller difference than from low to moderate dust scenarios due to melt season shifting into a season of lower evaporative demand. The sensitivity of flow timing to dust radiative forcing of snow albedo is maintained under future climate scenarios, but the sensitivity of flow volume reductions decreases with increased climate forcing. These results have implications for water management and suggest that dust abatement efforts could be an important component of any climate adaptation strategies in the UCRB.

More Colorado River Basin coverage here.

Black Hills Exploration & Production is bankrolling $7 million cost to develop #ColoradoRiver diversion near De Beque

Colorado River near De Beque
Colorado River near De Beque

From The Grand Junction Daily Sentinel (Gary Harmon):

Ranchers and De Beque residents will gain irrigation water and the energy industry will have access to water for drilling under a project that will pump water out of the bottom of the Colorado River. Energy companies will pay most of the cost of the project that will use an existing intake at the bottom of the river to draw water out and pipe it into existing ditches and a small impoundment that energy companies can draw on for their drilling activities.

“It’s definitely an asset to the community,” said De Beque-
area rancher Tom Latham. “The town will benefit, irrigation and agricultural people will benefit and the oil and gas business will benefit.”

Latham and rancher Dale Albertson represent the Bluestone Water Conservancy District along with members of the board of the Colorado River Water Conservation District in pushing the project, for which work could begin this year.

Called the Kobe Project, the water it draws from the Colorado will be devoted mostly — 75 percent — to agricultural use and 25 percent for industrial use.

Black Hills Exploration & Production is bankrolling almost all the estimated $7 million development cost, some of which it will recoup through lower water costs and from other energy companies that use water from the project, officials said.

The Kobe project will draw 25 cubic feet per second from the Colorado, with 5 cfs set aside for industry and the rest for De Beque and agriculture, said Ray Tenney, an engineer with the River District.

The water won’t necessarily expand agriculture in the area, but it will be a welcome layer of security against continued drought, Latham said.

“The last two years, if it had been in place, it would have been a benefit,” Latham said.

Water availability also will make it easier to develop natural gas in areas that otherwise might have been impossible because of the difficulty of trucking it in, said Mesa County Commissioner Steve Acquafresca, who until recently served as the county’s representative on the project.

“This really is a great local project converting local conditional rights to absolute rights for diverse purposes,” Acquafresca said.

The project also illustrates the need for water to remain in the Colorado as opposed to being diverted east to the Front Range.

“If we want to be more than a donor basin, we need to have a robust economy,” Acquafresca said.

“Kobe is a good example of what we need to be doing here with our water resources.”

More Colorado River Basin coverage here.

It’s Wastewater Worker Recognition Week

AWRA – Colorado Section EARLY BIRD PRICES EXTENDED : MAY 2 Annual Symposium – Water Hazards: From Risk to Recovery

Northern Water’s 2013 Annual Report is hot off the presses

Map of the Northern Integrated Supply Project via Northern Water
Map of the Northern Integrated Supply Project via Northern Water

Click here to read the report. Here’s an excerpt:

In April when the Board considered the quota, forecasts indicated below average runoff. Because the C-BT Project delivered more than 300,000 acre feet in 2012, storage reserves were significantly below normal in early 2013, and inadequate to provide the higher quota many would have preferred.

As this roller coaster year progressed, mountain snowpack and resulting runoff increased. The Board felt it prudent to not increase the declared 60 percent quota, hoping to build C-BT reserves and be better positioned for future years.

The September record-breaking rains and devastating floods will be forever remembered. Our hearts go out to all who were impacted. In addition to the personal and public property devastation, water supply infrastructure suffered severe damage. In many areas streamflows exceeded maximum levels recorded since the advent of South Platte Basin irrigation in 1859.

Rebuilding has been the region’s focus since the floods. Some efforts have succeeded, some will require more time. The Colorado Water Conservation Board stepped up and provided

As this roller coaster year progressed, mountain snowpack and resulting runoff increased. The Board felt it prudent to not increase the declared 60 percent quota, hoping to build C-BT reserves and be better positioned for future years.

The September record-breaking rains and devastating floods will be forever remembered. Our hearts go out to all who were impacted. In addition to the personal and public property devastation, water supply infrastructure suffered severe damage. In many areas streamflows exceeded maximum levels recorded since the advent of South Platte Basin irrigation in 1859.

Rebuilding has been the region’s focus since the floods. Some efforts have succeeded, some will require more time. The Colorado Water Conservation Board stepped up and provided $2.55 million in grants to help those in need. Northern Water was honored to act as CWCB’s agent, administering over 100 grants in accordance with CWCB criteria and direction.

Northern Water suffered relatively light flood damage compared to many. We are blessed with a very dedicated and talented workforce that aggressively took on the challenge of flood recovery. As a result, Northern Water completed flood repairs by early January.

Reclamation repaired additional C-BT Project facilities damaged by the floods. The exception is the Dille Tunnel Diversion on the Big Thompson River, which will likely not be fully operational until the beginning of the 2015 irrigation season.

In 2013 Northern Water successfully finished refurbishing the original Carter Lake outlet. This past year also marked the culmination of a 13-year effort to meet the annual water delivery requirements of the Colorado River Endangered Species Recovery Program. Through a unique solution that does not diminish C-BT Project yield, water was released from Lake Granby for beneficial uses in the Grand Valley while also meeting endangered species needs. This effort, implemented by Northern Water, was funded by East Slope entities that divert water from the Colorado River.

More Northern Colorado Water Conservancy District coverage here.

USGS: Geologic Sources and Concentrations of Selenium in the West-Central Denver Basin, Including the Toll Gate Creek Watershed, Aurora, Colorado, 2003–2007

selenium

Here’s the abstract from the USGS (Suzanne S. Paschke/Katherine Walton-Day/Jennifer A. Beck/Ank Webber/Jean A. Dupree)

Toll Gate Creek, in the west-central part of the Denver Basin, is a perennial stream in which concentrations of dissolved selenium have consistently exceeded the Colorado aquatic-life standard of 4.6 micrograms per liter. Recent studies of selenium in Toll Gate Creek identified the Denver lignite zone of the non-marine Cretaceous to Tertiary-aged (Paleocene) Denver Formation underlying the watershed as the geologic source of dissolved selenium to shallow ground-water and surface water. Previous work led to this study by the U.S. Geological Survey, in cooperation with the City of Aurora Utilities Department, which investigated geologic sources of selenium and selenium concentrations in the watershed. This report documents the occurrence of selenium-bearing rocks and groundwater within the Cretaceous- to Tertiary-aged Denver Formation in the west-central part of the Denver Basin, including the Toll Gate Creek watershed. The report presents background information on geochemical processes controlling selenium concentrations in the aquatic environment and possible geologic sources of selenium; the hydrogeologic setting of the watershed; selenium results from groundwater-sampling programs; and chemical analyses of solids samples as evidence that weathering of the Denver Formation is a geologic source of selenium to groundwater and surface water in the west-central part of the Denver Basin, including Toll Gate Creek.

Analyses of water samples collected from 61 water-table wells in 2003 and from 19 water-table wells in 2007 indicate dissolved selenium concentrations in groundwater in the west-central Denver Basin frequently exceeded the Colorado aquatic-life standard and in some locations exceeded the primary drinking-water standard of 50 micrograms per liter. The greatest selenium concentrations were associated with oxidized groundwater samples from wells completed in bedrock materials. Selenium analysis of geologic core samples indicates that total selenium concentrations were greatest in samples containing indications of reducing conditions and organic matter (dark gray to black claystones and lignite horizons).

The Toll Gate Creek watershed is situated in a unique hydrogeologic setting in the west-central part of the Denver Basin such that weathering of Cretaceous- to Tertiary-aged, non-marine, selenium-bearing rocks releases selenium to groundwater and surface water under present-day semi-arid environmental conditions. The Denver Formation contains several known and suspected geologic sources of selenium including: (1) lignite deposits; (2) tonstein partings; (3) organic-rich bentonite claystones; (4) salts formed as secondary weathering products; and possibly (5) the Cretaceous-Tertiary boundary. Organically complexed selenium and/or selenium-bearing pyrite in the enclosing claystones are likely the primary mineral sources of selenium in the Denver Formation, and correlations between concentration of dissolved selenium and dissolved organic carbon in groundwater indicate weathering and dissolution of organically complexed selenium from organic-rich claystone is a primary process mobilizing selenium. Secondary salts accumulated along fractures and bedding planes in the weathered zone are another potential geologic source of selenium, although their composition was not specifically addressed by the solids analyses. Results from this and previous work indicate that shallow groundwater and streams similarly positioned over Denver Formation claystone units at other locations in the Denver Basin also may contain concentrations of dissolved selenium greater than the Colorado aquatic-life standard or the drinking- water standard.

More South Platte River Basin coverage here.

USGS: Remediation Scenarios for Attenuating Peak Flows and Reducing Sediment Transport in Fountain Creek, Colorado, 2013

Fountain Creek Watershed
Fountain Creek Watershed

Here’s the abstract from the USGS (Michael S. Kohn/John W. Fulton/Cory A. Williams/Robert W. Stogner, Sr.)

The U.S. Geological Survey (USGS) in cooperation with the Fountain Creek Watershed, Flood Control and Greenway District assessed remediation scenarios to attenuate peak flows and reduce sediment loads in the Fountain Creek watershed. To evaluate these strategies, the U.S. Army Corps of Engineers Hydrologic Engineering Center (HEC) hydrologic and hydraulic models were employed.

The U.S. Army Corps of Engineers modeling system HEC-HMS (Hydrologic Modeling System) version 3.5 was used to simulate runoff in the Fountain Creek watershed, Colorado, associated with storms of varying magnitude and duration. Rain-gage precipitation data and radar-based precipitation data from the April 28–30, 1999, and September 14–15, 2011, storm events were used in the calibration process for the HEC-HMS model. The curve number and lag time for each subwatershed and Manning’s roughness coefficients for each channel reach were adjusted within an acceptable range so that the simulated and measured streamflow hydrographs for each of the 12 USGS streamgages approximated each other.

The U.S. Army Corps of Engineers modeling system HEC-RAS (River Analysis System) versions 4.1 and 4.2 were used to simulate streamflow and sediment transport, respectively, for the Fountain Creek watershed generated by a particular storm event. Data from 15 USGS streamgages were used for model calibration and 7 of those USGS streamgages were used for model validation. The calibration process consisted of comparing the simulated water-surface elevations and the cross-section-averaged velocities from the model with those surveyed in the field at the cross section at the corresponding 15 and 7 streamgages, respectively. The final Manning’s roughness coefficients were adjusted between –30 and 30 percent at the 15 calibration streamgages from the original left, right, and channel-averaged Manning’s roughness coefficients upon completion of calibration.

The U.S. Army Corps of Engineers modeling system HEC-RAS version 4.2 was used to simulate streamflow and sediment transport for the Fountain Creek watershed generated by a design-storm event. The Laursen-Copeland sediment-transport function was used in conjunction with the Exner 5 sorting method and the Ruby fall-velocity method to predict sediment transport. Six USGS streamgages equipped with suspended-sediment samplers were used to develop sediment-flow rating curves for the sediment-transport-model calibration. The critical Shields number in the Laursen-Copeland sediment-transport function and the volume of sediment available at a given cross section were adjusted during the HEC-RAS sediment-model calibration process.

HEC-RAS model simulations used to evaluate the 14 remediation scenarios were based on unsteady-state streamflows associated with a 24-hour, 1-percent annual exceedance probability (100-year) National Oceanic and Atmospheric Administration Type II precipitation event. Scenario 0 represents the baseline or current conditions in the watershed and was used to compare the remaining 13 scenarios. Scenarios 1–8 and 12 rely on side-detention facilities to reduce peak flows and sediment transport. Scenario 9 has a diversion channel, and scenario 10 has a reservoir. Scenarios 11 and 13 incorporate channel armoring and channel widening, respectively. Scenarios 8 and 10, the scenario with the most side-detention facilities, and the scenario with the reservoir, respectively, were the most effective at reducing sediment transport and peak flow at the Pueblo, Colorado, streamgage. Scenarios 8 and 10 altered the peak flow by –58.9 and –56.4 percent, respectively. In turn, scenarios 8 and 10 altered the sediment transport by –17.7 and –62.1 percent, respectively.

More Fountain Creek coverage here.

The Lower Ark and Otero County enter into IGA to form the Arkansas Valley Rural Water Authority

The water treatment process
The water treatment process

From the La Junta Tribune Democrat (Bette McFarren):

On Wednesday, the Lower Arkansas Valley Water Conservancy District entered into an intergovernmental agreement with Otero County for the purpose of creating the Arkansas Valley Rural Water Authority. As Bill Hancock of the LAVWCD explained, this organization has been a long time coming about and is much needed in the valley so that small water companies may deal with new regulations on drinking water.
The organization will help the companies in many ways. First, it will enable them to apply for grants and loans to maintain or replace outdated equipment. More important, they can now speak as a group. They can get together a portfolio that will enable them to connect with the conduit (to receive higher quality water from Pueblo Reservoir). Perhaps the most important point of all, said Hancock, is that they will be able to hire a full-time person to deal with the extremely complex problems involved with water distribution and getting funds for improvement.

After passing the intergovernmental agreement which makes the organization possible, the LAVWCD appointed its two members of the AVRWA board, Wayne Snyder and Jolean Rose. Snyder has been working with the three founding members of the AVRWA for months to find a way to create the organization. Rose’s husband was one of the originators of the idea of the independent water companies joining forces. These companies are Valley Water, represented by Sam Fosdick; Vroman Water, represented by Kenny Wilson; Fayette Water, represented by Alan Franz. Other companies may join the association. The Otero County Commissioners entered into the IGA on Monday at their regular meeting. They will be taking applications for their two spots on the board. The other board member will be selected by the members of the AVRWA.

Terry Dawson, standing in for Roy Vaughan for the U.S. Bureau of Reclamation, gave the group the good news that we may actually be having a wet year. The Pueblo Reservoir is up to average for the first time in many years. As of April 14, 195,543 acre-feet are stored in Pueblo; 129,145 a/f of project water, 35,266 a/f of excess capacity water, 127,804 a/f of Project space in Pueblo, 70,161 a/f of Project space in Twin and Turquoise.

The melting of the snowpack will start early this year, predicts the Bureau. The problem with pumping the water from Turquoise to Twin Lakes has been solved with fixing the troublesome pump. In other words, the water situation looks good for agriculture. Dawson said the wet weather will continue through the spring to early summer, followed by a dry period, then another wet period in the fall, according to best predictions. A cautionary note: weather may be predicted with any degree of accuracy for only a week at a time.

More Arkansas River Basin coverage <a href="

NSF — Earth Week: Bark beetles change Rocky Mountain stream flows, affect water quality

mountainpinebeetles

From the National Science Foundation (Cheryl Dybas):

On Earth Week–and in fact, every week now–trees in mountains across the western United States are dying, thanks to an infestation of bark beetles that reproduce in the trees’ inner bark.

Some species of the beetles, such as the mountain pine beetle, attack and kill live trees. Others live in dead, weakened or dying hosts.

In Colorado alone, the mountain pine beetle has caused the deaths of more than 3.4 million acres of pine trees.

What effect do all these dead trees have on stream flow and water quality? Plenty, according to new research findings reported this week.

Dead trees don’t drink water

“The unprecedented tree deaths caused by these beetles provided a new approach to estimating the interaction of trees with the water cycle in mountain headwaters like those of the Colorado and Platte Rivers,” says hydrologist Reed Maxwell of the Colorado School of Mines.

Maxwell and colleagues have published results of their study of beetle effects on stream flows in this week’s issue of the journal Nature Climate Change.

As the trees die, they stop taking up water from the soil, known as transpiration. Transpiration is the process of water movement through a plant and its evaporation from leaves, stems and flowers.

The “unused” water then becomes part of the local groundwater and leads to increased water flows in nearby streams.

The research is funded by the National Science Foundation’s (NSF) Water, Sustainability and Climate (WSC) Program. WSC is part of NSF’s Science, Engineering and Education for Sustainability initiative.

“Large-scale tree death due to pine beetles has many negative effects,” says Tom Torgersen of NSF’s Directorate for Geosciences and lead WSC program director.

“This loss of trees increases groundwater flow and water availability, seemingly a positive,” Torgersen says.

“The total effect, however, of the extensive tree death and increased water flow has to be evaluated for how much of an increase, when does such an increase occur, and what’s the water quality of the resulting flow?”

The answers aren’t always good ones.

Green means go, red means stop, even for trees

Under normal circumstances, green trees use shallow groundwater in late summer for transpiration.

Red- and gray-phase trees–those affected by beetle infestations–stop transpiring, leading to higher water tables and greater water availability for groundwater flow to streams.

The new results show that the fraction of late-summer groundwater flows from affected watersheds is about 30 percent higher after beetles have infested an area, compared with watersheds with less severe beetle attacks.

“Water budget analysis confirms that transpiration loss resulting from beetle kill can account for the increase in groundwater contributions to streams,” write Maxwell and scientists Lindsay Bearup and John McCray of the Colorado School of Mines, and David Clow of the U.S. Geological Survey, in their paper.

Dead trees create changes in water quality

“Using ‘fingerprints’ of different water sources, defined by the sources’ water chemistry, we found that a higher fraction of late-summer streamflow in affected watersheds comes from groundwater rather than surface flows,” says Bearup.

“Increases in stream flow and groundwater levels are very hard to detect because of fluctuations from changes in climate and in topography. Our approach using water chemistry allows us to ‘dissect’ the water in streams and better understand its source.”

With millions of dead trees, adds Maxwell, “we asked: What’s the potential effect if the trees stop using water? Our findings not only identify this change, but quantify how much water trees use.”

An important implication of the research, Bearup says, is that the change can alter water quality.

The new results, she says, help explain earlier work by Colorado School of Mines scientists. “That research found an unexpected spike in carcinogenic disinfection by-products in late summer in water treatment plants.”

Where were those water treatment plants located? In bark beetle-infested watersheds.