The Imperial Irrigation District claims, “broad powers” to control distribution to members #ColoradoRiver #COriver

The American Canal carries water from the Colorado River to farms in California’s Imperial Valley. Photo credit: Adam Dubrowa, FEMA/Wikipedia.

From The Desert Sun (Ian James):

A legal fight over water rights is heating up in the Imperial Valley, pitting farmers against their own irrigation district in a struggle for control of the biggest water entitlement along the Colorado River.

A judge’s ruling has forced the Imperial Irrigation District to repeal its plan for apportioning water, which had set limits on how much water individual growers could use on their fields.

The case has also touched off heated arguments at meetings — and sharply worded letters between lawyers — about landowners’ water rights and the role the district should play as a “trustee” in divvying up and delivering water. While some farmers suggest the two sides should settle the dispute, others argue the differences are too substantial to reach an agreement and will need to be decided by a California appeals court.

Michael Abatti, the farmer who sued the district to challenge its water apportionment plan, stood at a meeting on Tuesday and told the IID board he strongly disagrees with the agency’s statement in a recent letter that it has “broad powers” to determine how much water is distributed to growers…

The case has elicited arguments stretching back over a century of western water law, from the 1922 Colorado River Compact to a 1980 U.S. Supreme Court decision, Bryant v. Yellen, in which the justices said Imperial Valley landowners “have a legally enforceable right, appurtenant to their lands, to continued service” by the irrigation district.

The Imperial Valley enjoys some of the oldest rights to Colorado River water, which began flowing to the area via canal in 1901 and turned this swath of the Sonoran Desert into a lush, green agricultural powerhouse.

Farming drives the local economy, contributing an estimated $4.5 billion annually in economic output and spending by ag companies and employees. The valley produces crops including alfalfa, wheat, lettuce, broccoli, onions, carrots, sugar beets, cauliflower, cabbage, Brussels sprouts and cantaloupes, among others.

The irrigation district supplies about 530 agricultural customers, delivering water through a network of canals and pipes that fan out across the valley like the lines on a circuit board.

The amount of water the district delivers is subject to an overall annual cap. When there are overruns, as happened in 2011 and 2012, the district is required to pay back the difference by taking less during subsequent years.

Responding to the two consecutive years of overruns, the IID board adopted its so-called Equitable Distribution Plan in 2013 in an attempt to stay within the annual limit. The district’s officials used what they called a “hybrid” method, basing the per-acre water limits partly on each farmer’s historical water use and partly on a standard amount applied to all growers.

#Drought expands over the southwest and southern plains #ColoradoRiver #COriver #snowpack

US Drought Monitor March 27. 2018.

From The Associated Press (Susan Montoya Bryan) via The Arizona Daily Sun:

A federal drought map released Thursday shows dry conditions intensifying across northern New Mexico and into southwestern Arizona. Every square mile of Nevada and Utah also are affected by at least some level of dryness.

On the southern high plains, Oklahoma is ground zero for the worst drought conditions in the United States.

The exceptional drought in the Panhandle — an area dominated by agriculture — has more than doubled in size. Many farmers rely on precipitation to help water their crops as pumping groundwater is the only other option…

Crop conditions around the region are declining as extreme drought spans from Kansas and Oklahoma to California. In New Mexico, about three-quarters of the winter wheat crop is in poor to very poor condition as meaningful moisture has been scarce since last fall.

Along the Rio Grande in southern New Mexico, the irrigation allotment will be less than half of what farmers received last year. Water orders will begin next week and officials with the local Irrigation district are encouraging growers to use their surface water as soon as crops demand it…

In Arizona, there’s concern for ranchers as the poor range conditions have left stock tanks dry. On the Navajo Nation, a drought emergency was declared earlier this month and residents have started hauling water for their sheep and other livestock…

But officials aren’t expecting any cuts to the water delivery systems that serve much of Arizona’s population.

From The Albuquerque Journal (Ollie Reed Jr.):

The best snowpack in the state, in the Rio Chama Basin, is at 45 percent of normal. The Jemez and Pecos river basins are at 16 and 3 percent of normal, respectively, and the Gila and Rio Hondo basins are at zero.

Royce Fontenot, senior hydrologist in the Albuquerque office of the National Weather Service, said the snowfall season has peaked out.

“We are done there,” Fontenot said during a New Mexico Drought Monitor Working Group session this week. “What we have on the mountains is what you are going to get. What you see is what you get for (spring) runoff.”

[…]

The Drought Monitor Work Group, made up of members of the National Weather Service and state and federal agencies, determines the extent and severity of drought in the state. An updated drought map released Thursday shows that nearly 99 percent of New Mexico is in some stage of drought and more than 34 percent, the northern third of the state, is in extreme drought.

During the Working Group conference, Marshal Wilson of the New Mexico Department of Agriculture said there are reports that farmers in the northeast are planting less corn this year due to dry conditions and that livestock producers are downsizing their herds.

“We have started to see things getting pretty tough,” Wilson said. “The winter wheat crop was bad because we had no snow. We need moisture, and when we get it, high winds dry it out pretty quick.”

Wilson said ranchers are hauling water to herds and confronting a hay shortage that will make supplemental feeding of cattle a challenge.

Anthony Chavez, stage agricultural program specialist with the U.S. Department of Agriculture’s Farm Services Agency, said 15 northern counties now qualify for the federal Livestock Forage Program, which makes funds available to help ranchers buy feed for their cattle once a county has been in severe drought for eight consecutive weeks…

If there are silver linings, they are in the possibility of a better-than-normal summer monsoon season and the fact there is more water stored in most state reservoirs now than there was at this time last year.

Graphic credit: NOAA

A flurry of research illuminates snow’s foes — @HighCountryNews

From The High Country News (Emily Benson):

Depending on where in the West you are, this winter was either a winner or a big bust: Montana, for example, is swathed in snow while parts of the Southwest are dismally bare. As of late March, the Upper Colorado River Basin snowpack was well below average.

But the longterm trend is clear: Years of research show that the region’s snowpack is declining as the climate warms. About two-thirds of the West’s water comes from snow, and “we’re losing that natural reservoir,” says Sarah Kapnick, a hydroclimate scientist with the National Oceanic and Atmospheric Administration.

Forecasting the coming winter’s bounty months in advance could help Westerners prepare for surplus or scarcity, Kapnick says. Better predictions would allow officials time to implement flood control or water conservation measures, for example, and help farmers decide whether to plant thirsty crops or hardier ones.

The first step is understanding what can diminish a snowpack, like hotter temperatures, humid air and wind-blown dust. Here are three recent studies that dive into the snowpack and its foes:

Credit: California Cooperative Snow Survey via YouTube

THE STUDY: “Exploring the origins of snow drought in the Northern Sierra Nevada, California,” Earth Interactions, December 2017.

THE TAKEAWAY: Not all droughts are dry. A “snow drought” can occur even when there’s plenty of precipitation if it’s so warm that it falls as rain instead of snow.

WHAT IT MEANS: To understand what causes snow droughts, scientists from the Desert Research Institute in Reno, Nevada analyzed decades of monthly snow measurements from the northern Sierra Nevada, near Lake Tahoe. They identified several snow droughts caused by a variety of factors, including dry periods, warm weather and rain falling on snow and melting it.

The researchers found that some weather patterns have inconsistent impacts: For example, atmospheric river storms, bands of water-soaked air that can drench the West Coast, might initiate a snow drought if they bring mostly rain, or end one if they deliver snow.

While snow droughts aren’t a new phenomenon — the scientists found evidence for one in 1951, the earliest year they studied — it does appear that they are becoming more common. “We’re seeing them stack up a little bit more now,” says Benjamin Hatchett, one of the study’s co-authors. That trend will likely continue as the climate warms, stressing both ecosystems and economies that depend on snow and the water it holds.

Fog rolls in below snow-dusted peaks on Washington’s Olympic Peninsula. In relatively humid places like the Pacific Northwest, more water melts from the snowpack during the wintertime than in more arid regions. Brooke Warren/High Country News

THE STUDY: “Humidity determines snowpack ablation under a warming climate,” Proceedings of the National Academy of Sciences, January 2018.

THE TAKEAWAY: The amount of moisture in the air drives wintertime dips in the snowpack. There’s more midwinter snowmelt in humid corners of the West than arid ones.

WHAT IT MEANS: Scientists from the University of Nevada Reno and the University of Utah scrutinized decades of weather and snow records from 462 sites across the West to understand why water in the snowpack sometimes dwindles during the wintertime.

They found that relatively wet places experienced more wintertime melting. During humid weather — a stretch of foggy days, for example — water vapor in the air condenses on the snowpack, releasing energy and heating the snow. Clouds and moist air also prevent nighttime cooling, pushing the snowpack closer toward thawing, sometimes well before spring. “If (snow) is melting and not sticking around to the times later in the year when we need and expect that water, that’s a real problem,” says Adrian Harpold, a hydrologist at the University of Nevada Reno and co-author of the study.

Harpold says parts of the Western snowpack could be hit hard by amplified humidity in the future. Because a warmer atmosphere can hold more moisture, places near the ocean or other large bodies of water will likely experience more humidity — and more melting.

Layers of dust stripe the sides of a pit dug into the snow in Colorado. Dust deposited or exposed on the surface of the snowpack contributes to faster warming and melting. Center for Snow and Avalanche Studies

THE STUDY: “Variation in rising limb of Colorado River snowmelt runoff hydrograph controlled by dust radiative forcing in snow,” Geophysical Research Letters, December 2017.

THE TAKEAWAY: Snow covered in dust melts faster than clean snow, because it absorbs more energy from the sun. In some areas, dust influences the speed of spring snowmelt more than air temperature.

WHAT IT MEANS: Dust blown in from the Great Basin and the Colorado Plateau periodically darkens alpine slopes in southwest Colorado’s San Juan Mountains. A team of scientists examined air temperature, dust deposition and how quickly a handful of rivers in the area rose in the spring between 2005 and 2014. Dust was the dominant factor: Spring runoff happened more quickly in years with more dust, regardless of whether the air was warm or cool.

Understanding how dust affects snowmelt and spring runoff is crucial for water management, says Tom Painter, an author of the study and a snow hydrologist at NASA’s Jet Propulsion Laboratory. A bigger, faster pulse of water could stress infrastructure and increase the risk of flooding.

That doesn’t mean air temperature is completely irrelevant. After all, that’s what determines how much precipitation falls as snow rather than rain. “That is an enormous impact on the water resources as well,” Painter says.

Emily Benson is an assistant editor at High Country News.

Stunning drops in solar, wind costs mean economic case for coal, gas is ‘crumbling’ — ThinkProgress

Aspen gets more than half of its electricity from wind turbines just north of I-80 in the Nebraska panhandle. Photo credit The Mountain Town News.

From ThinkProgress (Joe Romm):

Prices for solar, wind, and battery storage are dropping so rapidly that renewables are increasingly squeezing out all forms of fossil fuel power, including natural gas.

The cost of new solar plants dropped 20 percent over the past 12 months, while onshore wind prices dropped 12 percent, according to the latest Bloomberg New Energy Finance (BNEF) report. Since 2010, the prices for lithium-ion batteries — crucial to energy storage — have plummeted a stunning 79 percent.

“The economic case for building new coal and gas capacity is crumbling,” as BNEF’s chief of energy economics, Elena Giannakopoulou, told Bloomberg.

At the same time, solar and wind plants — which are increasingly being built with battery storage — are eating into the utilization of existing coal and gas plants, making them far less profitable. For instance, the super-efficient combined-cycle gas turbine (CCGT) plants that have been popular in recent decades, were designed to be used at full power between 60 percent and 90 percent of the time.

But their actual utilization rate (also called the “capacity factor”) has been plummeting in recent years, and is now close to a mere 20 percent in countries as diverse as China, Germany, and India.

#Colorado adds 70,000 new folks in 2017

Colorado Springs with the Front Range in background. Photo credit Wikipedia.

From KOAA.com (Bill Folsom):

Growth in Colorado is booming. State census numbers just out, show Colorado’s population jumped by around 70,000 people in 2017…

When it comes to water supply, Colorado Springs utilities planners look decades into the future. Within the last year they completed what is called an Integrated Water Resources Plan. “That really looked at our future water supply, 50 plus years out. And a big component of that was estimating our future demand based in part on population.”

[…]

The supply is strong right now and into the near future, but they know long term growth will require expanding our water system. Front Range water comes from an extensive system of reservoirs, pumps and pipes. “If we didn’t change our system at all with our current configuration or our water supply system we’re probably good on water supply for at least another 20 to 25 years.” Growth, however, is expected to continue, so planning is happening now for future water needs. “When we need to start thinking about bringing in additional storage, maybe expanding some of our reservoir storage, perhaps building new reservoirs.”

#Drought news: The aridification of the #ColoradoRiver Basin #COriver

Click here to go to the US Drought Monitor website. Here’s an excerpt:

Summary

Early in the drought week, moderate precipitation fell in an area covering southern Minnesota stretching southeastward through central Iowa and Illinois, southern Indiana, Kentucky, southwestern Virginia, and much of North Carolina. Heavier precipitation fell in coastal California and the Sierra range. Coastal Oregon and Washington also saw moderate to heavy precipitation amounts during the first half of the drought week. The Northeast experienced its fourth Nor’easter in as many weeks. Near the end of the drought week, a swath of precipitation fell from Texas, eastern Oklahoma, into Missouri and Indiana. The dry pattern continued for the drought stricken areas of the southern Rockies and Plains and parts of the Southeast…

South

Precipitation was generally above normal (0.5-2.0 inch surpluses) across north central Texas, eastern Oklahoma and extreme northwestern Arkansas during the USDM period. During the last 30 days, much of Texas, Oklahoma and Louisiana were running 1-3 inches below normal while Arkansas was as much as 5 inches above normal. According to the USDA, 65 percent of wheat in Texas was in poor to very poor condition while 72 percent of topsoil moisture across the state was short to very short. Moderate and Extreme drought was expanded in central and parts of southern Texas. Precipitation continues to miss western Oklahoma where 28-day streamflows are running below the fifth percentile and precipitation for the last 6-months is around 20 percent of normal. Extreme drought was expanded to cover more of the Panhandle of Oklahoma, reaching into Kansas and Texas. Drought and dryness is not currently affecting the majority of the other states of the region…

High Plains

Precipitation was light across the region during the USDM period as, generally speaking, less than 1 inch of precipitation fell. Aside from Kansas and Colorado, precipitation during the past 30-days was just ahead of normal as surpluses of 0.50 to 1 inch fell in much of North Dakota, eastern South Dakota and eastern Nebraska. Winter wheat conditions were rated 49 percent poor to very poor in Kansas while 69 percent of topsoil moisture across the state was short to very short. In southern Kansas, 180-day precipitation departures are 4-8 inches below normal. In southwestern South Dakota, recent precipitation allowed for D0 and D1 to be contracted. Severe drought (D2) was contracted in west central Colorado and in the Dakotas. Extreme drought (D3) was expanded southern and western Colorado and southern Kansas…

West

Copious amounts of precipitation fell in the West during the USDM period, helping to restore the below-normal seasonal mountain snowpack in the Sierra. In the lower elevations, the atmospheric river event caused flash flooding and mudslides in the same area where forest fires last December charred the landscape. Little to no precipitation fell during the week in Arizona and New Mexico. Despite the recent precipitation in California, departures are evident beyond 30 days. At the 6-month time scale, precipitation amounts are 30-50 percent of normal in Southern California. However, for the same period (6-month), the recent storm brought the precipitation totals closer to normal in the central and northern Sierra. River basin snow water content now measures 75-90 percent of average in the central Sierra. The recent storm allowed the contraction of drought across much of the West this USDM period. However, where the precipitation did not fall (Desert Southwest and northwestern New Mexico), Severe and Extreme drought (D2-D3) was expanded.

*For details on Eastern Colorado and Eastern Wyoming, refer to the High Plains region…

Looking Ahead

During the next 5 days, precipitation amounts are forecast to be high (3-5 inches) in an area stretching from Louisiana, Arkansas, Alabama, western Tennessee and into Kentucky. Elsewhere, lighter precipitation is forecasted to fall in the northern and central Rockies, High Plains, and Northeast. The drought-stricken Four Corners region, western Texas and the Southwest are expected to continue to be dry.

The 6-10 day outlook from the Climate Prediction Center calls for an increased chance of below-normal precipitation in the High Plains stretching into the Great Lakes region while the highest probability of above normal temperatures is centered around the Southwest. The probability of above-normal precipitation is highest in the South. Below-normal precipitation is most likely to occur across parts of the Southwest.

From KUNC (Luke Runyon):

“Everybody talks about 2001 and 2002,” [Chuck] McAfee says. “That one was a very dry time just like this is. This is appearing to be scarier and worse.”

By most measures, portions of the American southwest in the Colorado River Basin are in their 18th year of drought. A handful of wet years dot the historical record in that stretch of time, but storms haven’t brought enough moisture to fill reservoirs and replenish groundwater. It’s the longest period of sustained dry and warm weather since consistent records have been kept.

That’s leading some to ask: If a drought lasts that long, is it still a drought or something else entirely?

[…]

The lack of robust conversations about the dry conditions might be a symptom of our limited vocabulary to describe what’s going on, says Brad Udall, a climate and water researcher with Colorado State University.

“Language is how you think, right? It’s how your opinions form and how your thought processes work. If you have the wrong words in your thoughts, you might actually come up with the wrong solutions,” Udall says.

Udall and other academics with the Colorado River Research Group published a paper arguing that our conversations about drought in the southwest need to change — specifically the word “drought.” It’s no longer a helpful concept in talking about the fundamental climate shifts reshaping the southwest, Udall says.

“Drought is often viewed as a lack of water and is viewed as a temporary situation,” Udall says.

But the latest science points toward a drier, warmer future for the Colorado River Basin, Udall says. If we see that change as “drought,” as something that eventually goes away, we hold onto false hope and fail to adequately prepare…

“This isn’t really drought,” [Udall] says. “This is the ongoing aridification of the Colorado River Basin and we think we should start to talk about it in these terms rather than this older term, ‘drought.’”

Here’s the March 2018 Drought Update from the Colorado Water Conservation Board (Taryn Finnessey) and Colorado Division of Water Resources (Tracy Kosloff):

Despite near normal precipitation across most of the state in February, March precipitation has been well below average statewide. Currently Colorado is experiencing the 3rd lowest snowpack on record, with only 2002 and 1981 being drier. Extreme drought has expanded to cover most of Southwestern Colorado, The San Luis Valley and Southeastern Colorado. West Slope providers with limited storage are concerned about the demand season and thinking about possible restrictions, while Front Range providers are thinking about conservation messaging.

  • As of March 23rd, statewide snowpack at SNOTEL sites is 69 percent of average. The North and South Platte basins have experienced the highest levels of precipitation in the state, at 90 and 81 percent, respectively. While the Yampa & White and Colorado River Basins are slightly lower at 80 percent. The southern half of the state has been significantly drier with the Southwest basins of the San Miguel, Dolores, Animas & San Juan, Rio Grande, Gunnison and Arkansas all well below normal precipitation at 54, 54, 61 and 58 percent respectively.
  • Many basins’ year –to-date precipitation, based on SNOTEL is tracking near 2002, as is the state as a whole.
  • 74 percent of the state is in some level of drought classification with 24 percent in moderate drought, 30 percent in severe drought and 20 percent classified as extremely dry. An additional 16 percent of the state is experiencing abnormally dry conditions (see image on reverse side).
  • Reservoir storage statewide is at 116 percent of normal, with all basins above average. The Arkansas basin is reporting the highest average storage at 145 percent. The Southwest basins of the San Miguel, Dolores, Animas & San Juan have the lowest storage levels in the state at 105 percent of normal.
  • The Surface Water Supply Index(SWSI) values improved slightly for March 1, but remain below normal with much of the western slope classified as moderate to extremely dry. These values are expected to decline when new numbers are released on April 1, this is largely the due to below average streamflow forecasts.
  • Streamflow forecasts are well below average for the vast majority of the state and near normal in isolated areas including the Blue River, St. Vrain and Cache La Poudre basins (see image on reverse side).
  • Short term forecasts show that temperatures will be more seasonal with a normal chance of precipitation, however longer term forecasts indicate increased likelihood of below average precipitation and above average temperatures.
  • A weak La Niña remains active and is projected to transition to neutral conditions in May or June, indicating that warm and dry conditions are likely to persist through the spring. While the monsoonal rainfall forecast is still uncertain, above average temperatures should continue into the summer months.
  • Statewide Basin High/Low graph March 25, 2018 via the NRCS.

    Statewide SNOTEL snowpack is well below average at [72] percent of normal, and tracking close to 2002 levels. To reach a normal snowpack peak we would need to 480 percent of normal accumulation. Snowpack typically peaks in early to mid April.

    March 1 streamflow forecasts are below 60 percent of average for nearly all of southern Colorado, while the central portion of the state ranges from 70-80 percent of average. With dry conditions throughout March the April 1 streamflow forecasts are projected to decline.

    Click here to read the current drought assessment from the Colorado Climate Center. Click here to go to the NIDIS website hosted by the Colorado Climate Center.

    #Snowpack news: Disappointing snow accumulation season for most of the West

    Western spring snowpack has been below normal six of the past seven years, meaning less water during the traditionally dry summer months. Graphic credit: Climate Central

    From Climate Central:

    Even with the heavier snow in parts of the West last week, the snowpack depth measured at the end of the season for the West as a whole is below normal. It is a shift from last year’s snow surplus but is more representative of the long-term trend; 2011 and 2017 were the only two years this decade in which the snowpack was above normal. The Northwest had a favorable snowfall season, but drought returned to California after last year’s wet season, with extreme drought now extending eastward from California to the Southern Plains. Arizona and New Mexico are particularly dry, with each state receiving less than half of its normal snowfall through the end of March.

    As the world continues to warm from increased concentrations of greenhouse gases in the atmosphere, early spring snowpack has been trending downward. In addition to more intense droughts from decreased snowpack, warming winters mean that the percentage of winter precipitation that falls as snow is decreasing, which also contributes to the snowpack decline.

    While the West has a long history of droughts and wet periods, the droughts have been getting more intense over the past century. This has led to a depletion of deeper groundwater, which takes more than a single wet season to recover. According to the National Environmental Education Foundation, water managers in 40 states expect water shortages in some parts of their states in the next 10 years.

    From The Sopris Sun (Will Grandbois):

    The Roaring Fork Conservancy’s weekly snowpack report has the watershed as a whole at 75 percent of normal — better than the southwestern part of the state but not as robust as parts of northern Colorado and the Front Range. According to Education & Outreach Coordinator Liza Mitchell, area snowpack usually peaks around April 1, but that’s just a milestone, not a point of no return.

    “We’re going to have above average years and we’re going to have below average years,” she said. “While there’s definitely concern, there is sort of a silver lining in that we’re coming off of two years that were well above average… Our reservoirs are like savings accounts for a not-so-rainy summer. When it becomes really bad is when we have back-to-back years like this.”

    The Conservancy and local partners have also put effort into programs that will help residents, ranchers and wildlife weather tough years. The Crystal River Management Plan, for instance, makes it possible for irrigators to reduce their usage without losing their water rights.

    “The only certainty is that things will become more unpredictable, so we’re trying to set ourselves and the river up for success — be proactive instead of reactive,” Mitchell said. “Each and every one of us is a water user and therefore water diverter.”

    Karl Wetlaufer, a hydrologist and assistant supervisor with the National Resources Conservation Service Colorado Snow Survey, gestures to indicate how high snowpack has been in past years at the McClure Pass site. Data collectors would have to climb the rungs up to the second, higher door to access the shelter.

    From Aspen Journalism (Brent Gardner-Smith):

    For much of the winter, the snowpack at McClure Pass hovered around the second-lowest measurement on record for a 30-year period.

    By Thursday, March 22, the McClure Pass site and the Independence Pass site had dipped to the lowest ever recorded snow-water equivalent for that date.

    “It’s a very notable statistic because [McClure Pass] has a pretty long period of record — 38 years,” said Karl Wetlaufer, a National Resources Conservation Service hydrologist and assistant supervisor with the Colorado Snow Survey. “It definitely indicates there will be well below normal streamflow resulting from those areas.”

    It’s one thing to read about record low snowpack in a graph, and quite another when you see what it looks like on the ground where the data is gathered.

    At an early March Water Education Colorado workshop, participants traipsed around McClure Pass on snowshoes digging snow pits, measuring snow depth, and testing the snow-water equivalent of snow samples, looking for clues about this year’s spring runoff.

    That’s because today’s snow is tomorrow’s water.

    At the top of the 8,755-foot pass is a SNOTEL (short for snow telemetry) site, which is an automated system of sensors that collect weather and climate data hourly and beam it to the NRCS office in Boise, Idaho. There are 115 SNOTEL sites across Colorado, mostly in remote, mountainous watersheds.

    SNOTEL sites have a precipitation gauge, a pressure-sensing snow pillow, a snow-depth gauge, and an air temperature sensor. Some enhanced sites measure soil moisture content and humidity. They run on solar panels and also come equipped with a small shelter that housees the cables and wires that run the unit.

    Currently, the snow-water equivalent at McClure Pass is around 55 percent of normal and the water year-to-date precipitation is around 62 percent. Manual measurements from the group recorded the McClure Pass snowpack at around two feet deep and the snow-water equivalent, which is the liquid content of the snow, measured around 21 percent.

    The information gleaned from SNOTEL sites as well as from manual measurements by hydrologists can reveal a lot about what to expect from spring runoff.

    The entire Roaring Fork watershed is at 76 percent for snow-water equivalent and 67 percent of normal for water year-to-date precipitation. The National Resources Conservation Service releases a monthly water supply outlook report based on SNOTEL data. For March 1, the Roaring Fork Basin was predicted to be at 59 percent of average volume for April through July. That dropped to 49 percent of average by mid month.

    Liza Mitchell, education and outreach coordinator with the Roaring Fork Conservancy, left, and a participant in the Water Education Colorado SNOTEL workshop measure the snow-water equivalent of different layers of the snowpack. The liquid content of snow from this site measured roughly 21 percent. (March 2018)

    Not just depth

    Snow-water equivalent is the best predictor of streamflow volume, but there are other factors that can affect the volume, and especially the timing, of spring runoff. Some of those include the date when the ground becomes free of snow cover, solar radiation, whether there is a layer of dust in the snowpack, and the soil moisture conditions prior to winter’s first hard freeze.

    Liza Mitchell, education and outreach coordinator with the Roaring Fork Conservancy, explained that an earlier bare ground date means thirsty plants sprout earlier and absorb the water out of the soil, leaving less to flow into streams. Likewise, a dry fall means lower runoff. If dried-out soil froze with empty pore space, the snowmelt will fill these empty spaces in the soil first, instead of flowing into waterways.

    Dust on snow and solar radiation also can affect streamflow volume and timing. Spring storms from the southwest can deposit a layer of dark-colored dust on top of the snowpack causing it to melt quicker. Sometimes the dust layer is buried several inches or feet down.

    “If you have bright white snow, most of the solar radiation is going to get bounced off,” Mitchell said. “If there’s a dust event, it can change the reflectivity of the snow. Now that solar radiation is hitting a darker surface, most of the energy is being absorbed by the snowpack.”

    NRCS streamflow forecasts are created using only the SNOTEL data and don’t take into account these other environmental variables. The reason for this is mostly for simplicity’s sake. NRCS manages about 600 streamflow forecasts throughout the western United States with a limited staff, said Angus Goodbody, a Portland, Oregon-based NRCS forecast hydrologist.

    “If you have a good way to account for these other factors, then yes, they should improve your forecast,” Goodbody said. “But the biggest impact [these other factors] will have is not on the total volume, but the timing of runoff. We are predicting total volume, not when it’s going to happen.”

    A detail of a section of Castle Creek, the city of Aspen’s main water supply. Photo credit: Aspen Journalism

    Stream management

    So who could potentially be affected by low stream flows this year? The city of Aspen, for starters.

    Margaret Medellin, utilities portfolio manager for the city, said she will meet with City Council in April to discuss whether to implement water shortage restrictions in the coming months. The municipality does not have much water storage in the form of reservoirs, and it is required to keep a minimum amount of water in its stream sources of Maroon and Castle creeks.

    In Stage 1 restrictions, the city would ask residents to voluntarily reduce their water usage by 10 percent in what is essentially an awareness campaign. Stage 2 would require some restrictions on outdoor water use and Stage 3 could ban it altogether. All three stages would see an accompanying increase in water rates.

    “The city is committed to not drying up the creeks, so if they fall below a certain level, we stop diverting,” Medellin said. “We will use the little storage we do have or switch between one creek and the other.”

    Some irrigators, especially those with lower priority water rights, could suffer as a result of low stream flows. But the biggest loser would probably be instream flows and ecosystems, said Andy Schultheiss, executive director of the Colorado Water Trust.

    Instream flow rights are typically junior to most other water rights and streams can go dry in years when there isn’t much snowmelt coming down from the high country.

    “People in their homes won’t notice much of a difference, but that doesn’t mean there aren’t some really bad things happening,” Schultheiss said. “In even moderately dry years, the fish and the whole ecosystem tends to congregate in smaller and smaller pools, which creates disease and competition for food.”

    One potential solution is a pilot program that would let water rights owners lease water rights to the Colorado Water Conservation Board in order to keep more water in the stream. The Colorado Water Trust is a partner in this new voluntary water-sharing program that would benefit the state’s instream flow efforts.

    For more information or to track SNOTEL data, go to https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/water/snowsurvey/

    From The Glenwood Springs Post Independent (Jon Nicolodi):

    SnoTel sites are automated stations that collect data on snow, operated by the Natural Resources Conservation Service, and there are 115 in Colorado alone. While numerous measurements are taken, the most commonly used is snow water equivalent. Snow height is measured, but it doesn’t take into account the density of the snow, which can vary between 5 percent and 20 percent.

    The snow water equivalent is measured in inches and can best be thought of as what the depth of the water would be if you instantaneously melted the entire snowpack. Snow height is a favorite measurement of skiers and snowboarders. Snow water equivalent is a favorite measurement of scientists and anyone looking at water beyond the winter, which is a popular notion in Colorado.

    In an end-of-February report, Nick Barlow at the Colorado Avalanche Information Center reported the snow water equivalent of all of Colorado to be averaged at 73 percent, compared to what it historically is at the end of February.

    But not all areas of Colorado are favored equally with snowfall. The Front Range, including the North and South Platte basins, are at 90 percent and 91 percent, respectively. The lower half of the state, including the Arkansas, Gunnison, Upper Rio Grande and the southwesternmost watersheds, are in the low 60s or high 50s, bringing down that state average. The Yampa and the White in northwestern Colorado are at 81 percent of snow water equivalent compared to a median year.

    The Colorado River watershed, including the Roaring Fork and any other tributaries joining the Colorado along the I-70 corridor, comes in at 85 percent relative to its median snow water equivalent. On the whole, not too shabby. But not inspirational either.

    In most of Colorado, higher-than-average snowfall in February greatly helped these percentages. All of the previous months had been a bit dismal for winter, with November and December being particularly dry. The storms that did come were flanked by warm weather, so large portions of our snowpack melted away. In an average year, that snowpack and its snow water equivalent reach peak numbers by April 9 before melting as a whole, contributing to all of the industries that rely upon a hearty spring thaw, ample soil moisture and flowing water as deep into our dry summers as possible.

    Westwide SNOTEL basin-filled map March 27, 2018 via the NRCS.