Aridification is the New Megadrought

Updated: May 26

What is going on?

The Western United States is currently preparing for and experiencing what has historically been known as a megadrought. California, Nevada, Utah, Arizona, New Mexico, Texas, and Colorado are all measuring some level of Extreme or Exceptional drought according to the U.S. Drought Monitor. Each state is experiencing some combination of unusually dry monsoon seasons, below-average precipitation, reduced snowpack, early wildfires, and declining runoff and water flows from the regions key water sources of the Colorado River and Rio Grande.

While average statewide precipitation in Arizona between June and March is 11 inches, between June 2020 and March 2021, the state only received four inches. New Mexico is just as dire, with more than 50% of the state in the Exceptional drought category as of April 2021, while a year ago over 50% of the state was drought-free. Nevada is seeing wildfires already starting, and with Lake Mead’s water levels dropping, the Hoover Dam’s power generation will be impacted. Although the drought in Denver is improving, the majority of Western Colorado is in an Exceptional drought. The Sierra Nevada Mountains in California are currently only at 2% of their average snowpack for this time of year and Gavin Newsom has declared drought in two California counties. The situation in Texas isn’t much better, with 75% of the state in a Moderate level drought or worse.

As AIQUEOUS is #DataDriven, we see the cause of these “drought” conditions as clear and pointing to one key issue – warming temperatures driven by climate change. Climate change is no longer a far-off event that we can push on to the next generation to solve. It’s here to stay, currently underway, and already causing life-altering changes.

Aridification is the New Megadrought

Calling the current situation a drought, or even a megadrought, perpetuates a belief that this situation is temporary. A great paper by Overpeck & Udall explains how a drought implies there will be an end to these conditions and average rain and snow levels will return to “normal.” However, there is no drought. This is the new normal. With climate change in our faces, we need a new term. A word that helps the public grasp the severity of the situation and signifies the long-term implications of climate change.

Aridification, or aridity, is emerging as the new term that gives a more accurate depiction of what is really going on. At its base, aridity means “extreme dryness of the kind that can have serious impacts on humans and the natural systems upon which they depend.” Warming temperatures that cause aridity are only going to continue and expand if climate change is occurring. Drought is temporary, aridification is permanent.

The result of an increasingly arid climate is currently being seen in the Southwest and West. Overpeck & Udall lay out the symptoms and solution– progressively lower river flows, drier landscapes, higher forest mortality, and more severe widespread wildfires, not on a year-by-year basis but instead with a clear, long-term trend towards greater aridification that only climate action can stop.

To wrap it up nicely, Overpeck and Udall say; “the good news is that we know the cause of expanding aridification. Unfortunately, climate change and this aridification are likely irreversible on human timescales, so the sooner emissions of greenhouse gases to the atmosphere are eliminated, the sooner the aridification of North America will stop getting worse.” Even with decarbonization targets established within the United States and globally, as a nation we still have to address aridification now. What can and should be done?

Water Management and Conservation

The short-term solution will fall on water management policies and conservation. The challenge going forward as of now will be to ensure that water management policies reflect the scientific reality. Water management practices need to change – we can’t rely on the past anymore because at this point, the future is not going to look like anything we’ve ever seen in the past.

The Bureau of Reclamation has laid out several strategies to support reliable water and power deliveries in the West. They are applying climate change information to risk assessments for infrastructure and drought planning and helping to improve decision support tools to manage risks from wildfires. They are currently supporting initiatives that manage risks to water deliveries and water users and support reliable hydropower deliveries and fish and wildlife habitats (page 37-50 of report).

Seven states who rely on the Colorado River signed a short-term drought relief plan through 2026 that lays out possible reductions in water deliveries to lower the risks of the river’s reservoirs hitting extremely low levels. Despite this, the Bureau of Reclamation is predicting the first-ever major water conservation plan will be prompted to go into effect in June as Lake Mead’s water level is currently sitting at 1,079 feet. If the water level falls below 1,075 feet, a federal shortage would be declared. Utah's governor issued an executive order to enact water conservation at all state facilities, and the California Senate has also proposed a $3.4 billion spending budget to sustain programs and projects that will set them up for future dry months.

On a local level, there’s a number of ways small groundwater management districts and regional water planning groups can prepare for these arid conditions as Texas State Climatologist John Nielsen-Gammon lays out in his paper; “Unprecedented Drought Challenges for Texas Water Resources in a Changing Climate: What Do Researchers and Stakeholders Need to Know?.” It would be beneficial for small groundwater management districts to acquire in-house technical expertise on climate change science instead of relying on management’s personal opinions on climate change when it comes to making climate-related decisions. Having access to qualitative climate change information will drive better-informed and unbiased plans to manage climate change. Regional water planning groups will be better equipped to deal with the arid climate by developing multiple water supply sources that respond to climate change or megadroughts differently, or by developing water supply sources that are unresponsive to climate change.

But what are the strategies that Currents readers can pursue?

Urban Outdoor Water Conservation: per the Bureau of Reclamation, "irrigated turfgrass is one of the largest irrigated crops in the United States.” For something that we can’t eat, wear, or use to build anything, it’s astounding that we use drinking quality-water across the country to sustain it. AIQUEOUS clients such as City of Spokane, Washington and Scottsdale, Arizona work with their customers to convert turfgrass to less water-intensive landscapes, and Tempe, Arizona and San Antonio Water System offer home consultations to lower outdoor water use.

For our energy utility readers out there, the treatment and transport of drinking water can be a very energy-intensive business, and partnering with water utilities on outdoor water conservation could be a defensible strategy for claiming energy efficiency savings (let alone maintaining surface water for thermal electricity production).

Urban Indoor Water Conservation: indoor water conservation – especially of domestic hot water – is an effort that both water utilities and districts and energy utilities can back. New program design options such as "home water makeovers,” combining offers such as water-efficient fixtures and lower-carbon energy sources for hot water, could be co-delivered and financed by water and energy entities. And new technology providers such as Flume are offering customer insights on water use and how to engage with customers (see this month’s article by Flume in our newsletter!)

Integrated Resource Planning: finally, it's imperative that water conservation starts being considered a supply side strategy, much as legislation throughout the United States has driven energy efficiency to that status. Rather than simply focusing on altering the demand curve by lowering "gallons per capita per day,” conservation should be quantified as providing sustained acre-feet of savings at a given cost and compared to new technology investments (such as desalination, indirect or direct potable reuse or aquifer reinjection). All cost-effective conservation should be pursued *in addition* to risk management strategies around additional supply.

There is no question that aridification poses a substantial threat, however, we already have the technologies and institutional practices necessary to manage our water resources. Now it's up to us to acknowledge the challenge and get down to business.

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