Drying Times: Drought in Yamhill County

Fourteen years ago, when the News-Register ran an in-depth series titled “All Tapped Out,” Yamhill County, along with the entire American West, was facing a future of severe water shortages.

It still is.

Rainfall over the past 15 years has been below normal, and conditions this year have been especially severe. Mountain snowpacks and river levels are at record low levels, groundwater is severely depleted, and the parts of the state that aren’t in severe drought are in extreme drought.

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

Oregon is not alone in this predicament; all of Washington state is experiencing the same mix of severe and extreme drought, as is much of Nevada, and half of California is in exceptional drought, with most of the remainder in severe to extreme drought. Exceptional drought, the most acute stage, is also spreading into Nevada.

On August 13, the federal Climate Prediction Center issued an El Niño Advisory, noting that there is a greater than 90 percent chance that El Niño conditions will continue through the winter, and an 85 percent chance it will last into early spring of next year.

That means another year of warmer temperatures and low rainfall is likely, in an already parched region.

“In this 15 year period, we’ve had, maybe 12 that have been less than normal (rainfall) ... That makes quite an impact over the long term,” state Agricultural Water Resource Specialist Margaret Matter said.

Each year, she said, there’s a little less water stored in the soil, aquifers and reservoirs, “and next year’s a little drier. That adds up. And the warmer temperatures add quite a bit to depletion. It evaporates off the soil, evaporates off the surface of streams, as well as ... lakes or reservoirs. It also increases crop water use, any kind of plants’ transpiration. To keep cool, they’ve got to consume more water.”

Diana Enright, of the state Water Resources Department, said record low snowpack levels have added to the impact.

“The Natural Resources Conservation Service also says that what snow that fell melted two to three months early, which impacts not only instream flows, but also soil moisture,” Enright said. “According to the NRCS, soil moisture in the mountains and foothills is at new low levels…something that hasn’t been seen since they began keeping records.”

It’s a common assumption, Matter said, that warmer temperatures will mean longer growing seasons, but the reality isn’t that simple.

Whether there’s a longer growing season “isn’t just dependent on temperature; it’s also dependent on water availability,” she said.

“And then getting back to the forest, you just have a longer period of time when you’re more susceptible to fires.”

Climate scientists predict that Oregon can expect warmer, drier summers, but that doesn’t necessarily mean that every summer will look like this one, Matter said.

“A better way to think about it is that this is now a part of our range of variability,” she said.

In Oregon, lack of mountain snow, which normally keeps rivers plentiful with cold water, has left rivers extremely low, and so warm that fish are dying in record numbers.

On July 31, a coalition of conservation groups that included Columbia Riverkeepers, Idaho Rivers, Pacific Rivers Council, Snake River Waterkeeper, Water Watch and Wild Salmon, issued a press release saying that federal dam operators were breaking federal law by allowing the Columbia River to reach lethally hot temperatures.

The Clean Water Act bans Columbia River temperatures warmer than 68 degrees Farenheit; salmon die in temperatures warmer than 70. This summer, more than a quarter million of the sockeye salmon returning to spawn in the Columbia River have died because the high temperatures, and biologists say up to 80 percent of the run may die.

“This summer’s salmon catastrophe was entirely predictable and preventable,” Greg Haller, Conservation Director for the Pacific Rivers Council, said in the press release. “We’ve known for decades that dams create unsafe temperature pollution that will only get worse with climate change. We cannot allow energy profits to push salmon to the edge of extinction.”

Yamhill County, along with the Willamette Valley, is in severe drought, with extremely dry soil.

The state Water Resources Department has shut off water rights issued after 1980 for the South Yamhill River, and expects to cut them back to 1975 in the next few days.

In some areas of southern and eastern Oregon, rivers are so low that rights have been cut to “before statehood,” Enright said. “Regulation for senior water rights is occurring in places that have never seen regulation before, such as Polk County,” she said.

The cutbacks leave farmers to rely on stored water, if they have it, or wells drawing from increasingly low aquifers.

The Yamhill Basin, encompassing most of Yamhill County and the northern section of Polk County, covers 769 square miles, a land area of some 494,000 acres that drains to the Yamhill River, which in turn empties into the Willamette River.

It also, for practical purposes, is considered to include the 56-mile Chehalem Creek drainage basin in northeast Yamhill County.

The forested slopes of the Coast Mountain Range and their foothills around Amity and Dundee occupy about 40 percent of the basin’s land mass; farms and pastures cover another 34 percent.

Yamhill County is grass seed and wheat country, although it also produces hazelnuts, wine grapes, berries, tree fruits and vegetables, along with a wide variety of livestock.

There are 193,640 acres of farmland, and another 62,931 acres of range and pasture, according to the 2013 Yamhill Agricultural Water Quality Management Area Plan. Nine cities occupy about 8,000 acres of land, and continue to grow.

Dayton farmer Sam Sweeney said that growth, on some of the world’s richest farmland, is an unfortunate problem.

“I-5, it just draws people like a magnet, and it just seems like everybody can see western Oregon and wants a part of it,” he said. “Historically, we created our own problem by settling on some of the richest farmland and we can’t go back and change that, we’ve just got to go on the best we can, but ... it leads to an awful lot of political conflict.”

Oregon’s land use laws call for preserving farmland wherever possible, while its laws governing cities call for them to be able to grow in perpetuity.

Sweeney suggested that focusing on in-filling vacant lots, allowing smaller lots, and more vertical building might help relieve some of the pressure cities put on farmland, by competing for both land and water.

Both are highly contentious issues. Water in the west is more precious than gold.

The Willamette Valley, and more specifically, Yamhill County, have a complex hydrology.

Oregon’s landscape was formed by millions of years of violent natural events, including volcanic eruptions, massive earthquakes and catastrophic floods. Former seabeds crumpled and raised in the slow-motion collision of two tectonic plates that now form the Cascade and Coast Range mountains. Layers of basalt deposited by volcanoes form bedrock, more than a thousand feet deep in some areas, especially in the foothills, while the rich soil of the valley floor was deposited there by the Missoula Floods of the Pleistocene era, some 18,000 to 12,000 years ago.

Those floods, caused by the collapse of a wall of ice damming an inland sea in what is now western Montana, carved out the Columbia Gorge and roared into the Willamette Valley, filling it, as the water backed up.

The floods occurred repeatedly; geologists say there may have been as many as 100 over some 2,500 years. Much of the soil washed away along the route was deposited in the Willamette Valley, today considered one of the most fertile regions on earth.

One result of the complex geography of the region is that there is no single groundwater table, and the aquifer system is so complex that two wells drilled next to each other in some areas may hit two different aquifers – or none.

In 2014, the U.S. Geological Survey and the Oregon Water Resources Department jointly published a study of the groundwater flow system of the Willamette Basin, with an emphasis on the Central Willamette subbasin, about 6,700 square miles, out of the 12,000 square-mile Willamette and Sandy River drainage basins in northwestern Oregon.

One of the problems, it noted, is a lack of information.

“Groundwater is the only readily available resource to satisfy new demands for water in many areas,” it states. “Various factors limit the capacity of the groundwater system to meet these demands ... Available information and tools have not been sufficient to quantify these limiting factors.”

Recharge of groundwater in the Willamette Basin “is primarily from precipitation in the uplands of the Cascade Range, Coast Range and western Cascades areas,” it states.

Much gets used by human beings; much of it for agriculture.

“Mean annual groundwater withdrawal for water years 1995 and 1996 was about 400 cubic feet per second; irrigation withdrawals accounted for about 80 percent of that,” the report states.

It said that “The Central Willamette subbasin shows the greatest effects from pumping of any subbasin in the study area. Results ... indicate that average annual groundwater levels have declined in most parts of the Central Willamette subbasin since pumping began.”

That, it said, is with only about half of all permitted water rights in use, according to analysis by the state Water Resources Department.

The state, and indeed the entire American West, must deal with significant challenges. This series, “Drying Times,” focuses on some of those faced by Yamhill County and the surrounding region.