How safe are Denver Water’s dams? – News on TAP

Dam safety team conducts annual inspections, manages upgrades and trains for emergencies to keep facilities secure.

Source: How safe are Denver Water’s dams? – News on TAP

Your Watershed: We all can help protect our water supply — Annie Whetzel

Colorado River Basin in Colorado via the Colorado Geological Survey
Colorado River Basin in Colorado via the Colorado Geological Survey

Here’s a guest column from Annie Whetzel that’s running in the Glenwood Springs Post Independent:

If the fight in Battlement Mesa over the proposed injection well zone and its proximity to the water intake for the public water supply taught us two things, it is that our drinking water comes from the river and it is vulnerable.

Throughout the Roaring Fork Valley and the middle Colorado River watershed, unless you have a well in your backyard, our water comes from surface water. (In fact, even if you have a private well, it is susceptible to surface water and chemicals at the surface that leach down.)

Surface water includes the water that runs off the surface of the ground, everything from the mountains upvalley to the sidewalk downtown, flows to the river, and into our home.

Source water, essentially the source of our water, is important to protect. It is the water we depend on for daily life. The Middle Colorado Watershed Council hosted an event recently and many participants wanted to know how they could help our watershed now. A quick answer is: protect source water.

Last year, Glenwood Springs finalized its source Source Water Assessment and Protection Plan. The city worked with a statewide organization called the Colorado Rural Water Association to identify where our water comes from, understand areas where the source water might be at risk, and ways to mitigate those risks to water.

Glenwood Springs highlighted two crucial areas. One area comes from the Flat Tops and flows into the Colorado River in Glenwood Canyon. This tributary, while remote, is extremely vulnerable to severe fire damage.

If a large fire rolls across the area, the resulting sediment in the tributary could be enough to affect our water supply. It happened in Fort McMurray, Alberta. A fire tore through the area followed by heavy rains filling the river with sediment. The water treatment facility managers had to shut down their intake valve to the facility because the sediment in the water was too great for the system to handle.

The second area highlighted as at risk for contamination is along the Lower Roaring Fork River. This area is impacted by industry, transportation and the public. Here is where we get to work together and take feasible steps to ensure safe water.

The first step we all can easily take in protecting our source water is making sure we are handling our home waste and house run-off effectively. Paul Hempel, source water specialist for the Colorado Rural Water Association, said to best protect source water at an individual level is to “take care of household activities.”

Taking care of household activities includes managing toxic household supplies effectively and ensuring something as simple as oil and grease are handled correctly. That is, don’t pour it down the drain.

In a prepared statement, Trent Mahaffey from Glenwood Springs Waste Water Treatment Facility, explained that oil and grease can easily damage water and septic systems and can “create overflows into local waterways or property.” He reminds us all to freeze oil and grease and dispose of it in our household trash, and wipe out oily pans with a paper towel before washing them, to prevent excess oil going down the drain.

Another common source water contamination is runoff directly from a house or driveway. Hempel mentioned that porous surfaces are helpful to prevent excess runoff. Runoff from the house directly to a sidewalk or down a driveway can easily collect debris, oil, animal droppings and other contaminants like fertilizers on its way to the storm drain or ditch. If you have a downspout, create a gravel catchment for the water so it doesn’t have the opportunity to pick up large contaminants on its way to the river.

Better yet, avoid potential contaminants all together. Hempel stresses that the most important aspect of protecting source water is to simply be aware. This means understanding that what we spray down our driveway or pour down our drain affects our water supply. We should strive to avoid fertilizers with nitrates and washing our car in the driveway. Even if we protect the flow of water to the storm drain with porous surfaces, it is possible for surface water to seep into our groundwater, which will also make its way to the river.

How can we help our watershed? Be aware of where our water comes from and be aware of what we are adding to the system. Let’s protect our source water.

Annie Whetzel is with the Middle Colorado Watershed Council, which works to evaluate, protect and enhance the Middle Colorado River Watershed through the cooperative effort of watershed stakeholders. To learn more, go to http://www.midcowatershed.org or on Facebook at http://facebook.com/midcowatershed.

@ClimateSociety: Weak La Niña Replaced With Neutral ENSO, and Uncertainty

Here’s the release from the International Research Institute for Climate and Society (Elisabeth Gawthrop):

Since last month’s briefing, sea-surface temperatures have warmed in the area of the central equatorial Pacific Ocean that define El Niño and La Niña events, called the Nino3.4 region. Last week, the weekly anomaly for Nino3.4 was +0.1ºC — the first time it’s been above 0.0ºC since June. The first image below shows the latest week’s anomalies.

While the sea-surface temperatures (SSTs) point to a neutral ENSO state, the convection patterns in the equatorial Pacific (i.e. at what longitudes along the equator clouds and thunderstorms form) continue to show a La Niña-like pattern. Although this pattern is what is most likely to in turn influence precipitation patterns around the world, it is expected to weaken or disappear during the remainder of February and early March.

The upcoming seasonal forecasts are not showing much in the way of La Niña influence. “The models are expecting the convection patterns to return to neutral very soon, such as within the coming few weeks,” said Barnston. “The March-May climate is not expected to be materially influenced by the current cloudiness conditions.” The National Oceanic and Atmospheric Administration’s Climate Prediction Center issued a Final La Niña Advisory last week.

ENSO Forecasts
To predict ENSO conditions, computers model the SSTs in the Nino3.4 region over the next several months. The graph in the first image of the gallery below shows the outputs of these models, some of which use equations based on our physical understanding of the system (called dynamical models), and some of which use statistics, based on the long record of historical observations.

The mean of the statistical models’ forecast is similar to that of last month, with Nino3.4 SSTs staying around 0ºC or just above through the end of the year. The mean of the dynamical models’ forecast, especially later in the year, has increased from last month’s forecast. These dynamical models now call for anomalies around +0.8ºC as the northern hemisphere’s summer comes to a close. Last month’s forecast from the dynamical models didn’t quite reach +0.5ºC.

These forecasts, however, extend past what’s known as the spring predictability barrier — a function of ocean dynamics that makes it hard to predict ENSO past June of each year, so uncertainty is high.

The IRI/CPC probabilistic ENSO forecast issued mid-February 2017. Note that bars indicate likelihood of El Niño occurring, not its potential strength. Unlike the official ENSO forecast issued at the beginning of each month, IRI and CPC issue this updated forecast based solely on model outputs. The official forecast, available at http://1.usa.gov/1j9gA8b, also incorporates human judgement.
The IRI/CPC probabilistic ENSO forecast issued mid-February 2017. Note that bars indicate likelihood of El Niño occurring, not its potential strength. Unlike the official ENSO forecast issued at the beginning of each month, IRI and CPC issue this updated forecast based solely on model outputs. The official forecast, available at http://1.usa.gov/1j9gA8b, also incorporates human judgement.
This graph shows forecasts made by dynamical and statistical models for SST in the Nino 3.4 region for nine overlapping 3-month periods. Note that the expected skills of the models, based on historical performance, are not equal to one another.
This graph shows forecasts made by dynamical and statistical models for SST in the Nino 3.4 region for nine overlapping 3-month periods. Note that the expected skills of the models, based on historical performance, are not equal to one another.

Based on these model outputs, odds for La Niña are close to zero for the next several seasons, with neutral conditions dominating (see second graph in gallery above). The warmer SSTs shown in the plume graph, especially in the dynamical models, are reflected in the increasing likelihood for El Niño conditions later in the year.

The official probabilistic forecast issued by CPC and IRI in early February shows a similar overall pattern. This early-February forecast uses human judgement in addition to model output, while the mid-February forecast relies solely on model output.

From NOAA (Emily Becker):

Well, that was quick! The ocean surface in the tropical Pacific is close to average for this time of year, putting an end to La Niña, and forecasters expect that it will hover around average for a few months. Let’s dig in to what happened during January, and what the forecast looks like.

Not with a bang

This La Niña wasn’t exactly one for the record books. Our primary index, the three-month-average sea surface temperatures in the central Pacific Niño3.4 region, only dipped to about 0.8°C cooler than the long-term average during the fall of 2016. However, these cooler-than-average temperatures persisted for several months, and the atmosphere over the tropical Pacific responded as expected to the cooler waters. Namely, during the fall and winter to date, the Walker Circulation was strengthened: stronger near-surface east-to-west trade winds, stronger upper-level west-to-east winds, more rain than usual over Indonesia, and less rain over the central Pacific.

Monthly sea surface temperature in the central tropical Pacific Niño 3.4 region, from OISST.v2 temperature data. Data shown is the difference from the 1981-2010 average. Climate.gov graph from CPC data.
Monthly sea surface temperature in the central tropical Pacific Niño 3.4 region, from OISST.v2 temperature data. Data shown is the difference from the 1981-2010 average. Climate.gov graph from CPC data.

During January, the sea surface temperature edged close to normal, and the average temperature in the Niño3.4 region was just about 0.3°C below normal by the end of the month. (Note, this is using the weekly OISST data. There are some differences between our sea surface temperature data sets, which Tom described in detail here.)

Another factor that we watch is the temperature of the tropical Pacific Ocean below the surface. Over the past few months, the amount of cooler-than-average water at depth has been decreasing, and by the end of January it had disappeared. These deeper waters often give an idea of what we can expect at the surface in following months. Meaning, the lack of cooler water at depth makes it unlikely that the surface will cool off again substantially in the next few months

Monthly average heat content in the upper 300m of the equatorial Pacific. Data shown is the difference from the 1981-2010 average between 180°W and 100°W. Climate.gov graphic from CPC data.
Monthly average heat content in the upper 300m of the equatorial Pacific. Data shown is the difference from the 1981-2010 average between 180°W and 100°W. Climate.gov graphic from CPC data.

How will global warming affect Colorado River flows?

Summit County Citizens Voice

Water woes ahead for the Southwest

qwer The Colorado River will be hit hard by climate change. @bberwyn photo.

Even if precipitation stays the same or increases slightly in the next few decades, Colorado River flows are likely to dwindle due to increasing temperatures in the West. The projected warming in the 21st century could reduce flows by half a million acre feet per year, according to a new study to be published in the AGU journal Water Resources Research.

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#Snowpack news: SW basins lead the way = 157% of normal

Click on a thumbnail graphic to view a gallery of snowpack data from the NRCS.

And here’s the Westwide basin-filled map for February 20, 2017.

westwidesnotel0220017

Humans causing climate to change 170 times faster than natural forces — The Guardian

Greenland ice canyon filled with melt water in summer 2010.Ian Joughin, UW APL Polar Science Center
Greenland ice canyon filled with melt water in summer 2010.Ian Joughin, UW APL Polar Science Center

From The Guardian (Melissa Davey):

For the first time, researchers have developed a mathematical equation to describe the impact of human activity on the earth, finding people are causing the climate to change 170 times faster than natural forces.

The equation was developed in conjunction with Professor Will Steffen, a climate change expert and researcher at the Australian National University, and was published in the journal The Anthropocene Review.

The authors of the paper wrote that for the past 4.5bn years astronomical and geophysical factors have been the dominating influences on the Earth system. The Earth system is defined by the researchers as the biosphere, including interactions and feedbacks with the atmosphere, hydrosphere, cryosphere and upper lithosphere.

But over the past six decades human forces “have driven exceptionally rapid rates of change in the Earth system,” the authors wrote, giving rise to a period known as the Anthropocene.

Steffen and his co-researcher, Owen Gaffney, from the Stockholm Resilience Centre, came up with an “Anthropocene Equation” to determine the impact of this period of intense human activity on the earth.

Explaining the equation in New Scientist, Gaffney said they developed it “by homing in on the rate of change of Earth’s life support system: the atmosphere, oceans, forests and wetlands, waterways and ice sheets and fabulous diversity of life”.

“For four billion years the rate of change of the Earth system has been a complex function of astronomical and geophysical forces plus internal dynamics: Earth’s orbit around the sun, gravitational interactions with other planets, the sun’s heat output, colliding continents, volcanoes and evolution, among others,” he wrote.

“In the equation, astronomical and geophysical forces tend to zero because of their slow nature or rarity, as do internal dynamics, for now. All these forces still exert pressure, but currently on orders of magnitude less than human impact.”

Report: Energy budget increases reduce mean streamflow more than snow–rain transitions: using integrated modeling to isolate climate change impacts on Rocky Mountain hydrology

Evaporation and transpiration graphic via the USGS
Evaporation and transpiration graphic via the USGS

Click here to read the report (Lauren M Foster, Lindsay A Bearup, Noah P Molotch, Paul D Brooks and Reed M Maxwell):

Abstract

In snow-dominated mountain regions, a warming climate is expected to alter two drivers of hydrology: (1) decrease the fraction of precipitation falling as snow; and (2) increase surface energy available to drive evapotranspiration. This study uses a novel integrated modeling approach to explicitly separate energy budget increases via warming from precipitation phase transitions from snow to rain in two mountain headwaters transects of the central Rocky Mountains. Both phase transitions and energy increases had significant, though unique, impacts on semi-arid mountain hydrology in our simulations. A complete shift in precipitation from snow to rain reduced streamflow between 11% and 18%, while 4 °C of uniform warming reduced streamflow between 19% and 23%, suggesting that changes in energy-driven evaporative loss, between 27% and 29% for these uniform warming scenarios, may be the dominant driver of annual mean streamflow in a warming climate. Phase changes induced a flashier system, making water availability more susceptible to precipitation variability and eliminating the runoff signature characteristic of snowmelt-dominated systems. The impact of a phase change on mean streamflow was reduced as aridity increased from west to east of the continental divide.