No letup in sight for Oregon drought
Kathie Dello, deputy director of Oregon Climate Service, said the earth is warming and Oregon is reeling from the impact.
A look at Oregon’s drought and its effects on local cities, agriculture and recreation.
Now Online:
n Drying Times: Drought in Yamhill County
n Water rights a forbidding tangle in the West
n No letup in sight for Oregon drought
n The Yamhill River is under stress
n Agriculture use strains limited water resources
n Catching raindrops one way to conserve
n Dryland farming provides an alternative
n Fishing in jeopardy as rivers get warmer and flows slow
n Schools and cities discuss how they conserve water
n Cities are trying to plan ahead to ensure a plentiful water supply
Much of the state depends on snowpack, which acts as a frozen reservoir before melting in the course of the spring and summer. Dello said, “We’ve seen our snowpacks decline for the past few decades.”
More than half of Oregon’s snow measurement sites were at their lowest level in recorded history last winter. Some had no measurable snow. What snow there was melted early, affecting both river levels and soil moisture.
Precipitation this year was relatively normal until February, but spring arrived unusually early and remained abnormally warm and dry. As a consequence, the Western Oregon snowpack melted three months early and peaked 60 to 90 percent below normal, according to the final Oregon Basin Outlook Report for 2015.
“This year looks a lot like the future,” Dello said. “It’s one of the worst droughts seen in decades.”
Future winters are expected to deposit more rain and less snow, disrupting the normal sequence, raising the specter of flooding as desperately needed water roars past uncaptured.
Gov. Kate Brown declared drought in 23 of Oregon’s 36 counties by mid-July and issued a public service announcement urging Oregonians to do their part by conserving. Dello underscored that, saying, “It’s not mandatory, but everybody can cut back on personal use.”
By mid-August, 15 cities, two water districts and three irrigation districts in Oregon had issued voluntary or mandatory water restrictions, including Carlton, in Yamhill County.
While McMinnville doesn’t face an immediate threat, other cities in Yamhill County do, as they generally rely on wells, springs or small tributaries.
Looking long range, McMinnville recently partnered with Carlton, Dayton and Lafayette to begin acquiring water rights on the Willamette River. The plan is to begin jointly tapping them as the need arises.
Racquel Rancier of Oregon’s Water Resources Department said rights are issued chronologically, the earliest being the most senior, thus the most certain. “Depending on the system, water right holders that have junior priority dates will be cut off each year to meet the needs of senior water right holders,” Rancier said.
She said the date when junior water rights are cut off depends on the amount available. “During a very dry year, the regulation may go farther back, or may occur earlier than normal,” Rancier said.
That being the case, McMinnville Water & Light not only established some new rights at the bottom of the seniority scale, but also purchased some older rights.
The local players aren’t the only ones considering the Willamette. Clearly, the rush is on.
That prompted Roy Haggerty, professor of hydrology and earth sciences at Oregon State University, to launch a six-year study called Willamette Water 2100 to project supply and demand through the end of the century. He’s now five years into it.
“What I’m trying to do with the project is understand the future of water resources in the Willamette River Basin over the course of the twenty-first century,” Haggerty said. He’s using global climate data and projections of population and economic growth to develop a model of the basin’s water system.
While global warming is reducing snowpack, which promises to decrease stream flows, he said, the Willamette is rain as well as snow-fed and typically holds up fairly well when enough rain falls on Oregon’s west side. He said the pattern ahead looks likely to feature reasonably wet winters alternating with very dry summers.
The Willamette River Basin is less snowpack-dependent than most basins in the west, so should hold up better, Haggerty said.
“We live in a relatively water-rich place. Even with rising temperatures, the main stem of the Willamette River itself will have enough water.”
Currently, Oregon’s average precipitation is 88 percent of normal statewide. “That’s significantly drier than usual,” Haggerty said, “but not anywhere near the driest we’ve had.”
However, the Willamette, too, has been suffering in this summer’s hot, dry conditions, with low river levels, fish-killing high temperatures, and low flows. Restrictions on water use from the river have been in place for more than 100 days.
According to the U.S. Seasonal Drought Outlook’s three-month prediction, Oregon’s drought is expected to persist or intensify through the end of October.
It may last longer. On Aug. 13, the federal Climate Prediction Center issued an El Niño alert, saying there is a greater than 90 percent chance that El Niño conditions in the central equatorial Pacific Ocean will last through the winter.
El Niño conditions typically bring relatively warm, dry winters to Oregon. The CPC said there is an 85 percent chance the conditions will persist into early spring.
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