Drought intensifies in Lane County

This story has been updated.

It’s a simple formula: hot + dry = drought

But how we got here — and where it’s headed — is far more complex. Here’s what we know, based on data, scientists and local water managers.

Record-low rainfall

The landscape in Eugene and Springfield is so dry, it’s like a forgotten houseplant — once thriving; now tall, yellowing and brittle. When finally watered, the moisture pools on hardened soil, sinking in slowly.

That’s essentially what happened in mid-June, the last time significant rain fell following a record dry spring. April through June typically accounts for 25% to 30% of Oregon’s annual precipitation. But this year western Oregon experienced its fourth-driest April-to-June period, going back to 1895.

So when about half an inch of rain fell in June, some of that moisture soaked in, but most of it probably evaporated, state climatologist Larry O’Neill said. 

“And we haven’t had any rain since then,” O’Neill said. “That is one of the main drivers of why now we’re seeing moderate to severe droughts in the U.S. Drought Monitor throughout western Oregon, especially in Eugene.”

Drought intensity in Lane County began rising steadily in late April, around the 17th week of the year, and continued through the end of July.

All of Lane County is in drought, with nearly 73% of the area classified as severe, according to the Drought Monitor. The agency’s severity index, which ranges from 0 to 500, has climbed rapidly since rainfall tapered off in April and now sits around 250.

In Eugene and Springfield, widespread rainfall of more than 1 to 2 inches probably won’t arrive until the seasonal shift in late September.

Fire danger 

This dry spell, coinciding with a heat wave, came following a wet winter that fueled the growth of tall, dense grasses and shrubs.

“Everything’s really dried out already. It’s cured,” said O’Neill, using a scientific term to describe moisture loss — a word also commonly used for meat. In that sense, people can think of it a bit like drying bacon.

“All the grasses on the side of the road get really brown,” he said. “It is really crispy right now.”

And that brings fire danger. Under these conditions, even something as routine as driving or parking a vehicle can become a risk, because a hot exhaust system touching tinderlike grass can start a fire.

It’s why drought, combined with heat and wind, contributes to the above-normal significant wildfire potential now facing western Oregon.

Water supply

While Lane County is experiencing moderate drought, local leaders have not declared an emergency. Typically, a county board of commissioners must first vote to declare a local drought emergency. That action places the county on the state’s drought declaration list. If the governor also issues a drought declaration, the Oregon Water Resources Department can access state resources — such as permits or agreements to use restricted water supplies.

This year’s historically low spring rainfall and record-low stream flows across western Oregon have strained water systems, especially in the Coast Range. This led to the drought declaration in neighboring Lincoln and Douglas counties, which Gov. Tina Kotek issued July 10 and Aug. 4, respectively.

Officials in Newport are concerned enough about water supplies that they have alerted residents to voluntarily conserve water.

Florence is not facing such issues, public works officials told Lookout Eugene-Springfield. The North Florence Aquifer provides a robust supply.

Eugene Water & Electric Board also has a strong water supply that is more than sufficient to meet the water needs of its customers, spokesperson Aaron Orlowski said.

“We are always monitoring drought conditions, of course, but the biggest impact those conditions have on EWEB is related to our power supply and the regional availability of hydropower,” he said.

Nearly 80% of EWEB’s power comes from the Bonneville Power Administration, which operates 31 hydropower dams in the Columbia River Basin. Droughts have led to lower-than-usual power generating capacity at dams across the American West. 

The Springfield Utility Board operates seven well fields that draw from groundwater and supplement with water from the Middle Fork Willamette River when needed. A utility spokesperson said SUB has a steady, reliable supply.

Drought more frequent

Since the major 2015 drought across the Pacific Northwest, dry conditions have become more frequent. While low snowpack drove that year’s drought, this time it’s rapid spring warming and lack of rain.

Over the past decade, both the severity and amount of land experiencing drought have increased.

Lighter colors on the graph depict land experiencing milder forms of drought, while darker colors depict land experiencing intense drought. 

Aside from a break in 2010, the graph shows Lane County’s drought spells have grown longer. Even the most extreme forms of drought categorized as “exceptional” and “extreme” were once relatively unheard of in Lane County, but now, that categorization has become a more frequent summertime occurrence. 

O’Neill, the state climatologist, said spring seasons are getting warmer, and summer temperatures are growing hotter in part because of climate-warming pollution like greenhouse gases.

“Even if we were in an undisturbed climate, we probably would have been in a dry cycle right now,” he said. “But climate change is definitely making it quite a bit worse.”