Weekly Climate, Water and #Drought Assessment of the Intermountain West

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

A Southwest water dispute reaches the Supreme Court — @HighCountryNews

From The High Country News (Sarah Tory):

Southern New Mexico’s Mesilla Valley is like an island: a fertile patchwork of farm fields and groves of pecan trees surrounded by the brown Chihuahuan Desert.

For Mesilla Valley farmers, the metaphor rings true in other ways as well. Though they live in New Mexico, the residents of the roughly 90,000-acre-area are caught between their own state and Texas. The Rio Grande water they depend on is not technically New Mexico’s water, but rather part of the water that goes to Texas under the Rio Grande Compact, a treaty ensuring that Texas, New Mexico and Colorado get their fair share of the river. New Mexico’s delivery obligation to Texas hinges on collecting enough water in Elephant Butte Reservoir, 90 miles from the Texas border and the neighboring Mesilla Valley. Unfortunately, that leaves the farmers downriver in a complicated no-man’s-land of interstate water management.

“We cringe when we hear, ‘Not one more drop to Texas,’ because that means not one more drop for us,” says Samantha Barncastle, the lawyer for the Elephant Butte Irrigation District, which manages and delivers irrigation water to Mesilla Valley farmers.

After more than a decade of back-and-forth between New Mexico and Texas, the fight has finally reached the Supreme Court. The first round of oral arguments took place on Jan. 8, with a final decision expected by early spring. For the farmers, the conflict has only heightened their sense of isolation from their own state — and made the costs of poor water management in a hotter and drier West more obvious than ever.

Elephant Butte Dam is filled by the Rio Grande and sustains agriculture in the Mesilla Valley of New Mexico.
Sarah Tory

Built in 1916 by the Bureau of Reclamation, Elephant Butte Dam made a large-scale agricultural economy possible in New Mexico’s dry south. But disputes between states over the river continued, especially during times of drought.

The latest stems from a 2014 lawsuit filed by the state of Texas, claiming that by allowing farmers in southern New Mexico to pump groundwater, New Mexico was depleting the water destined for Texas under the Rio Grande Compact.

Farmers in the Mesilla Valley receive a yearly allocation of 36 inches of water per acre from the reservoir, as long as flows in the Rio Grande are sufficient. But in the 1950s, a severe drought curtailed that allotment. To supplement irrigation supplies, the Bureau of Reclamation encouraged local farmers to pump groundwater.

“Everyone did,” recalls Robert Faubion, a fourth-generation local farmer.

When the current drought began in 2003, farmers came to rely more on their groundwater wells, sometimes receiving almost 80 percent of their yearly irrigation needs from the aquifer. (The region’s towns and cities, including Las Cruces, rely 100 percent on groundwater.) According to the U.S. Geological Survey Mesilla Basin Monitoring Program, between 2003 and 2005 the Mesilla Valley aquifer declined by up to 5 feet and held steady until 2011, when it began dropping sharply again. In some places, groundwater levels fell by 18 feet.

As the situation worsened, the Elephant Butte Irrigation District and its longtime rival in Texas, the El Paso County Water Improvement District, agreed that the time had come to resolve their grievances. So the two agencies settled on an “operating agreement” in 2008, which required New Mexico to relinquish some of its Rio Grande water to Texas in exchange for Texas ceasing its complaints about groundwater pumping.

The signing coincided with Valentine’s Day. “We had sort of a love fest,” says Gary Esslinger, the treasurer and manager of the Elephant Butte Irrigation District.

The love lasted until 2011, when, in a surprise move, then-New Mexico Attorney General Gary King sued the irrigation district and the El Paso County Water Improvement District No. 1 as well as the Bureau of Reclamation, arguing that the deal gave away too much of New Mexico’s water. The decision to sue one of its own irrigation districts was, to Barncastle, “incredibly strange.”

In 2014, Texas fired back with its own lawsuit against New Mexico, bringing us to today’s scenario: If the Supreme Court rules against New Mexico, the state budget will take a hit. New Mexico could owe billions of dollars in damages — on top of the $15 million already spent on legal fees — and potentially have to find additional sources of water to send to Texas, as a way to make up for its groundwater pumping.

According to Barncastle, the case is motivating stakeholders in southern New Mexico to work on a framework for better groundwater management. The impacts of climate change are adding yet another layer of uncertainty, since no one knows how weather patterns might affect water scarcity in the future.

Regardless, the outcome will have major implications, says southern New Mexico Sen. Joe Cervantes. Most of the state’s population and industry is located along the riparian corridor. “If the health of the Rio Grande is threatened, then all of those communities are put at risk,” Cervantes warned.

Correspondent Sarah Tory writes from Paonia, Colorado. She covers Utah, environmental justice and water issues.

Poncha Springs Trustees OK waterline loan

Water infrastructure as sidewalk art

From The Mountain Mail (Brian McCabe):

Poncha Springs trustees moved forward on the town’s water infrastructure project Monday as they voted unanimously to approve a loan from the Colorado Water Resources and Power Development Authority (CWRPDA) and to accept a bid for work on the water trunk line…

They then adjourned and convened as the board of the Water Activity Enterprise Fund.

As that board, they considered Ordinance 2018-1, a 30-year, zero percent interest loan through the CWRPDA not to exceed $2,450,000 for construction of a new water tower and improvements to the town’s water system.

Brian Berger, town administrative officer, presented the ordinance to the board of trustees. He explained that it originally was proposed to fund the trunk line with reserves, but because this loan had been lowered to zero percent interest, with repayments not due to begin for six to eight months, it was the best choice for the town.

He said in a memo to the board that this allowed the best options for well designs and type of elevated tank, and the town was “by no means” required to use the entire amount.

Joe DeLuca with the Crabtree Group, the engineering firm for the trunk line, presented the six bids received for the job.

Lowry Contracting, with a bid of $476,928.68, came in more than $200,000 less than the next lowest bid from ESCO Construction, at $687,784…

In their last order of business as the water board, the trustees decided to table until next month a consideration of the 2018 leasable water bids, as the board thought current bids might change in this fluid situation.

#Snowpack news

Westwide SNOTEL basin-filled map January 23, 2018 via the NRCS.

From 9News.com (Cory Reppenhagen):

In a normal year, 80 percent of the water used by Coloradans comes from snow. That’s 4 out of 5 cups of water.

A weekend snowstorm boosted Colorado’s snowpack up by 3 percent and is now at 63 percent of normal.

The reason that snowpack totals are frequently reported in the news, is that it is something the affects every single one of us. Anyone that drinks water, eats food, washes the dishes, takes showers, or uses water in any way…

the height of Rocky Mountains does a great job of pulling out even the slightest bit of moisture that’s left in the atmosphere.

In the winter, that water is stored as snowpack, which conveniently melts and runs down to us when we need it the most, the spring and summer.

Brian Domonkos, a snow survey supervisor with the Natural Resources Conservation Service (NRCS) monitors the snowpack every day. He told 9NEWS that water managers rely on their data to plan how to allocate water in the coming summer.

“We try to predict how much water is going to be in the streams come June and July,” said Domonkos.

That water will be used to drink, to water lawns, to grow food, to make power, and of course to recreate.

“We still have a significant portion of our winter left but we are beyond the halfway point,” said Domonkos.

He said our statewide snowpack deficit will likely remain, and while reservoir storage is high, a dry finish to this season might not hurt us this summer, but it will likely catch up to us at some point…

NRCS says the South Platte Basin would only need slightly more than normal snowfall for the rest of the year to get back to average, but areas of southern Colorado will need more than twice the amount of snow they normally get in February, March, and April.

NRCS analysis also shows that since 1981, Colorado has only received enough snow in the final three months of the snow season (February, March, and April) to overcome a deficit of this magnitude 3 times during that span.

The Upper Rio Grande Basin has never during that 36-year stretch received enough snow to overcome a deficit like this year’s, but the South Platte Basin has received enough snow to overcome it’s current deficit 17 times.

Key #climatechange effect: Loss of Piñons and the Western Water Cycle

Piñon pine (Juniperus_occidentalis). Photo credit: Wikimedia

Click here to access the report. Here’s the abstract:

Tree Mortality Decreases Water Availability and Ecosystem Resilience to Drought in Piñon-Juniper Woodlands in the Southwestern U.S.

Climate-driven tree mortality has increased globally in response to warmer temperature and more severe drought. To examine how tree mortality in semiarid biomes impacts surface water balance, we experimentally manipulated a piñon-juniper (PJ) woodland by girdling all adult piñon trees in a 4 ha area, decreasing piñon basal area by ~65%. Over 3.5 years (2009–2013), we compared water flux measurements from this girdled site with those from a nearby intact PJ woodland. Before and after girdling, the ratio of evapotranspiration (ET) to incoming precipitation was similar between the two sites. Girdling altered the partitioning of ET such that the contribution of canopy transpiration to ET decreased 9–14% over the study period, relative to the intact control, while noncanopy ET increased. We attributed the elevated noncanopy ET in the girdled site each year to winter increases in sublimation and summer increases in both soil evaporation and below-canopy transpiration. Although we expected that mortality of a canopy dominant would increase the availability of water and other resources to surviving vegetation, we observed a decrease in both soil volumetric water content and sap flow rates in the remaining trees at the girdled site, relative to the control. This postgirdling decrease in the performance of the remaining trees occurred during the severe 2011–2012 drought, suggesting that piñon mortality may trigger feedback mechanisms that leave PJ woodlands drier relative to undisturbed sites and potentially more vulnerable to drought.

From Water Deeply (Matt Weiser):

Piñon trees have been dying in droves across the West. Laura Morillas, lead author of the new study, found that losing piñon trees doesn’t necessarily free up more water in these arid habitats. It could mean the opposite.

This forest, in which piñon and juniper trees grow together, is a unique natural community common throughout the arid West. It covers millions of acres in nine states, but is most abundant in Colorado, Arizona, New Mexico, Nevada and Utah.

Piñon and juniper trees, somewhat shrubby and short, are not particularly majestic compared to a ponderosa pine or a sequoia. But they’re vitally important to people, wildlife and water supplies. By providing shade in sunny, high-elevation landscapes, piñon-juniper forests help ensure snow and rain last long enough to reach rivers and groundwater before evaporating.

Unfortunately, piñon trees seem to be particularly vulnerable to climate change. They’ve been dying in great swathes in recent years due to heat and drought. What does this mean for water supplies?

A new study led by scientists at University of New Mexico begins to answer that question. At a 10-acre research site, the researchers intentionally girdled the piñon trees (removed a strip of bark from their circumference) to kill them, then compared results over several years to a nearby control site. They found a surprising result: Losing piñon trees did not make more water available in the soil or for surviving juniper trees, as common sense would dictate. Instead, the entire test plot lost moisture more rapidly.