What’s Up With Water – May 17, 2021

In Australia, researchers say that rivers may be more vulnerable to extreme drought than was previously thought. Their examples come from the Australia’s southeastern region, where a decade-long drought ended in 2010. Even after years of normal rainfall, more than a third of the region’s rivers had not recovered to their pre-drought levels. The results of the study were published in the journal Science. The researchers concluded that drought leaves deep fingerprints on river systems, possibly changing how water circulates within them.

In the United States, Great Lakes states are seeing some relief from record-breaking high lake levels. In the last two years, high waters eroded shorelines and caused millions of dollars in property damage. But the trend lines are now changing. The U.S. Army Corps of Engineers said that water levels should be down this year because of reduced ice cover, drier weather in recent months, and more evaporation. The region will welcome the change. Last year lakes Michigan and Huron set eight monthly records for high waters. Rising waters damaged roads, eroded the shoreline, and flooded homes. Although lower lake levels could mean less erosion in the near-term, the Army Corps said that erosion and high water levels could still be an issue in the future.

In climate news, new research finds that many cities are failing to plan for a hotter future. CDP is a London-based group that works with investors, businesses, and cities to uncover climate risks. In that spirit, CDP surveyed more than 800 cities about their climate adaptation. The survey found that while more cities are disclosing climate risks, many are slow to act upon them. Forty-three percent do not have a climate adaptation plan. Even though water is one of the main impacts of climate change, only about half of the cities included water in their risk assessments. The survey also revealed financial constraints. It found that one in four cities lacks the funding to implement adaptation plans and policies.

Spring is generally a time of renewal for the watersheds of the western United States. Warmed by the lengthening days, the region’s towering mountain ranges shed their mantle of snow, releasing water into welcoming streams and reservoirs.

This year, though, the cycle is in disarray. Outside of the Olympic and Cascade ranges of Washington state, winter snows were subpar. The spring melt has been a grave dissapointment. From the Klamath to the Colorado and Rio Grande, watersheds are under stress once again, and water managers face difficult tradeoffs between farms, fisheries, and families. The main thing being renewed this spring is concern over the apparent inadequacy of the region’s water supply.

Becky Bolinger is Colorado’s assistant state climatologist. She summed up the scenario in five words: “This is a drought emergency.”

Bolinger was referring to the latest runoff forecast for Lake Powell, a large reservoir on the Colorado River. It’s the country’s second-largest reservoir. But this spring and summer, Lake Powell is expected to get water inflows that are a mere 28 percent of normal. The Bureau of Reclamation said this year’s inflows are on pace to be the third or fourth lowest in the last century. Today, the lake is just 34 percent of capacity — or, looking at the math another way, about two-thirds empty. Downstream states like Arizona are bracing for mandatory cutbacks next year.

What is worrisome is that the Colorado drought emergency that Bolinger described could apply to any number of western watersheds.

In California last week, Gov. Gavin Newsom expanded a drought declaration to include 41 of the state’s 58 counties. Water levels in the state’s two largest reservoirs — Oroville and Shasta — are about half of what they usually hold this time of year.

In the Klamath basin of southern Oregon and northern California, there are already lawsuits over how the Bureau of Reclamation is allocating scarce water from Upper Klamath Lake. The drought is forcing the federal agency to balance the needs of endangered fish species both upstream and downstream. It told farmers in the upper basin to expect very little irrigation water this summer.

In New Mexico, water managers say the Rio Grande through Albuquerque could run dry this summer, which would complicate water management efforts. Mike Hamman is chief executive officer of the Middle Rio Grande Conservancy District. He told Circle of Blue that his district faces what he calls a “three-pronged challenge:” delivering irrigation water to farmers, sending water downstream to Texas that is required under a federal compact, and protecting endangered species like the silvery minnow that rely on the river.

Dry conditions do not have uniform consequences, especially across so many states. Alvar Escriva-Bou is a research fellow with the PPIC Water Policy Center. He said that California is better prepared than it was for the last harsh drought, which lasted from 2012 to 2016. He said the metropolitan areas of Southern California are especially well positioned. These areas boosted water conservation and reuse and have benefitted from longer-term investments in storage.

Still, with water so scarce, pain is inevitable. In the previous drought, thousands of residential wells in California’s Central Valley failed. PPIC estimates that over two thousand shallow wells are at risk of going dry this summer. Farmers in the Central Valley, meanwhile, will need to fallow fields, pump groundwater, or buy water on the market after state and federal agencies cut their surface water allocation to the bone.

These persistent droughts raise a question. If conditions are dry nearly every year, is it really a drought? Or is it something altogether different? For example, the Colorado River basin has been drier than usual over the last two decades. Academics there say that new language is needed. Instead of calling these dry years a drought, they recommend the term “aridification.”

Drought suggests a temporary departure from normal. Aridification implies that the region’s climate, under the influence of heat-trapping gases in the atmosphere, is entering a different reality, one that is warmer and drier. Escriva-Bou noted that warm droughts are especially challenging. Warmer temperatures increase the risk of wildfires, heat streams to the point that fish cannot survive, and increase evaporation.

As in the Colorado River basin, winter precipitation in California was quickly devoured this spring by a hot and thirsty atmosphere and parched soils. Water managers like Grant Davis took notice. Davis is the general manager of Sonoma Water, a water agency that operates in California’s Sonoma and Marin counties. Davis has managed water in droughts before, but the nature of the dryness in his region, he says, is something new. As he put it,  “It’s come on faster, and it’s more dramatic and pronounced.”

And that’s “What’s Up With Water,” from Circle of Blue, where water speaks. More water news and analysis await you at circleofblue.org. This is Eileen Wray-McCann – thanks for being here.