From Circle of Blue (Brett Walton):

When water stops flowing, painful days are at hand.

89 percent of nine western states are in some form of drought, and more than a quarter of the region is considered in exceptional drought, the worst category in the U.S. Drought Monitor.

Droughts leave deep bruises that may not surface for months or years. Too much heat and too little rain can cause ecosystems to collapse and hasten the spread of non-native species.

Over the coming decades, a warming climate will cause more frequent and intense droughts, especially in the Colorado River basin.

It develops in stages, a story that builds upon itself. A few cloudless days. Then a rain-free week. Soon a hot, dry month.

Now the hills are brown and the crops need watering — the first signs of drought.

The intensely dry conditions that have settled over the American West and Upper Midwest this year are well past the brown hills stage. Nearly 89 percent of nine western states are in some form of drought, and more than a quarter of the region is considered in exceptional drought, the worst category in the U.S. Drought Monitor.

The indicators of widespread dryness are everywhere. Lakes Mead and Powell, the major reservoirs on the Colorado River, are 35 percent full with a two-year outlook that worsened each month this spring. California officials told vineyards along the Russian River in May that the system is too depleted for irrigation. In Utah’s Great Salt Lake in April, sailboats were lifted out of receding waters too shallow to float. In the Klamath River that flows between Oregon and California, few juvenile salmon are expected to survive this season. In Arizona, the Rafael Fire, burning in the Prescott National Forest some 25 miles southwest of Flagstaff, grew to 36,000 acres since it was sparked on June 18 by lightning.

When water stops flowing, painful days are at hand — even if the pain is not immediately evident.

“The complexity of the drought phenomenon is not well understood by most people,” said Roger Pulwarty. Some people will say that we’ve experienced drought before, he mused. “Well, not like these. Not for this extent, not really addressing all the diverse ways in which it affects our economy, through the environment, through trade.”

Pulwarty has wrestled with these questions about the consequences of drought longer than most. He was the director of the National Integrated Drought Information System, a drought monitoring and planning collaborative set up by Congress. And he was the coordinating lead author for a United Nations special report on drought that was published earlier this month.

Drought, like a hurricane, tornado, or earthquake, is a potentially dangerous natural hazard. But Pulwarty notes that droughts have distinctive characteristics that separate them from other calamities. They are geographically diverse, spreading across a few counties or entire watersheds and regions. They are slow to begin but can last indefinitely, some “megadroughts” upending social and political stability over several decades.

Drought, like a fearsome boxer, has a long reach. And like that fearsome boxer, the long reach of drought is pummeling.

One Thing Leads to Another…And Another

Specialists like Pulwarty, who is currently a senior scientist in the physical sciences laboratory at the National Oceanic and Atmospheric Administration, use the word “cascade” to describe the long reach.

Consider this chain of events. Drought increases the risk of fire. It dries out vegetation and kills trees, turning forests into matchsticks. Fires in river headwaters don’t just burn trees. They also send ash and debris into reservoirs and rivers. The Las Conchas fire in northern New Mexico in June 2011 pumped so much ash into the Rio Grande that the Albuquerque Bernalillo County Water Utility Authority had to close its drinking water intake on the river. When they rampage through developed areas, fires can contaminate plumbing systems and water distribution pipes with volatile organic chemicals. The smoke is a public health threat.

Or this scenario: low reservoirs mean that dams equipped with turbines generate less hydropower. Hoover Dam’s power-generating capacity is down 28 percent today compared to when Lake Mead is full. The Western Area Power Administration markets the power from Hoover and other federal hydropower projects in the West. Jack Murray, the acting vice president and desert southwest regional manager, told Circle of Blue that the shortfall in cheap hydropower means the agency has to make up the difference by buying more expensive — and sometimes more carbon-intensive — power on the spot market. That is an economic punishment for the small communities, irrigation districts, and Indian tribes that are some of the end users of the electricity.

“Drought filters through any economic activity in which water is involved,” said Pulwarty. Hydropower, farm production, shipping on inland waterways, commercial river rafting, nuclear plants that need water to cool their equipment — the list is long. Drought is also a mental and physical strain, weighing on the minds of farmers who can’t plant fields and homeowners who run short of water.

When farmers pump groundwater to counteract water deficits in rivers and lakes, shallower domestic wells can dry up, which is beginning to happen throughout California. As of June 21, the Department of Water Resources had received 64 reports of dry wells this month, the most in any month since August 2016.

There is a lesson here, drought researchers say. People can bankrupt a water system just as much as nature can. A full understanding of drought, they argued in a journal article published in January, takes into account the human failures of water and land management.

Besides dry wells, pumping too heavily in California’s San Joaquin Valley caused the land to compact and sink. It’s another example of the cascade. That land subsidence, in turn, buckled the canals that carry irrigation water, reducing their water-carrying capacity in some areas by 60 percent. The estimated cost to repair the three major canals suffering from subsidence damage is more than $2.3 billion.

Drinking water providers that rely on lakes instead of groundwater have a different concern in drought: the presence of algal blooms. Though some blooms contain toxins that are harmful to humans, the sheer mass of algae is also a problem, encumbering the water treatment process. The algae clog filters, which have to be replaced more frequently. There is more sludge to discard. These all raise costs, says Frank Costner, the general manager of Konocti County Water District. The blooms are particularly bad in Costner’s water source: Clear Lake, the second largest freshwater lake in California. Water testing done by the Big Valley Band of Pomo Indians on June 7 showed that toxins in the lake’s eastern basins had already reached dangerous levels.

Droughts leave deep bruises that may not surface for months or years, Pulwarty said. Even after rains return, reservoirs and aquifers take time to refill. Trees killed this year are fuel for next year’s fire. Too much heat and too little rain can cause ecosystems to collapse and hasten the spread of non-native species.