Rockne Roll / News-Register##An irrigation gun waters young trees. Typically, fruit and nut trees require irrigation until they are well established, although mature orchards may not need watering in most years. With soil moisture heavily depleted this year, even some mature trees are suffering from lack of water.
Rockne Roll / News-Register##An irrigation gun waters young trees. Typically, fruit and nut trees require irrigation until they are well established, although mature orchards may not need watering in most years. With soil moisture heavily depleted this year, even some mature trees are suffering from lack of water.
By Nicole Montesano • Staff Writer • 

Agriculture use strains limited water resources

“I have never, ever seen it as dry as it has been this year,” Sweeney said. “There was a year that was close, 1977, and it started out the same way, but in the late spring it started to rain, and we got through it OK. That didn’t happen this year. We got some rain, but not enough to really soak the ground.”

The 2007 U.S. Census of Agriculture lists 2,115 farms in Yamhill County, with an average size of 86 acres. Sizes range from an acre or two to several thousand acres.

One of those farms belongs to Sweeney, who, with his wife Nancy, son Tom and daughter-in-law Pieper, farms 11,000 acres planted in tall fescue, perennial ryegrass, red clover, wheat, radishes for seed, marionberries, filberts, table beets, sweet corn and field corn.

Sweeney said the only one of his crops not irrigated at some point in its life cycle is the wheat. Even the filberts, better known as hazelnuts, are irrigated as young trees, although not once they mature.

“We couldn’t grow the row crops without (irrigation). Even the seed crops, we couldn’t grow without it. We could grow tall fescue and the perennial ryegrass, but we couldn’t get the yields,” he said. But Sweeney, along with the rest of the farming community, is worried about this year’s abnormally dry conditions.

“When I cross the bridges of the Yamhill River and I look down, I think, ‘Gosh I could almost step across,’ and you can’t tell if there’s any flow in those spots or not,” he said. The river supplies much of the irrigation water for local farmers.

There will be no relief until the fall rains arrive, and, Sweeney pointed out, “It’s hard to say when we will get a rain; sometimes it happens in very late August, sometimes not till October.”

Normally, he said, he plants red clover in the fall, and irrigates it to get it started, “and I kind of wonder if we’re going to be able to do that this year. It’s got all of us wondering: Is this one year out of 100, or one year out of two; can we expect the same next year?”

The Agricultural Water Quality Management Area Plan, produced every two years by the Yamhill Soil and Water Conservation District working with the Department of Agriculture, found in 2013 that there are 155,275 acres of non-irrigated farmland in the basin, 38,365 acres of irrigated farmland, and 62,931 acres of range and pasture land.

The report notes that “Much of the watershed is intensively farmed. ... Most of the major crops, such as cereal grains, orchards and grasses are grown on the low foothills and the main valley terrace. Irrigated vegetable and specialty crops such as nursery products, vegetables for processing and fresh market, corn for silage, hay and alfalfa are generally grown on the alluvial bottomlands.”

Grass and legume seed are by far the biggest crops, followed by hay and then wheat. Wine grapes comprised 5,800 acres in 2012, coming in behind grass and legume seeds, hay, wheat and hazelnuts. Changes in farming over the past century, the report notes, “have caused physical impacts in the basin. Most of the basin’s farmland was planted in dryland crops such as oats and barley until the early 1940’s. Since then, agricultural production in the basin has diversified to include irrigated specialty crops and a greater variety of dryland crops. The growth in specialty crops has been accompanied by increased withdrawals from streams in the basin.”

But the basin is becoming overdrawn, along with most of the American west. Oregon’s surface waters are over-allocated. Its groundwater resources are also becoming strained. The Oregon Water Science Center notes in a report on the Willamette River Basin that “the burgeoning population” of the area “is putting unprecedented demands on the water resources of the region,” and that increasingly, cities, farmers and individuals are turning to groundwater.

However, Oregon Agricultural Water Resource Specialist Margaret Matter noted, “We’ve been learning we do not understand our groundwater system as well as we thought we did.”



Grass, legume seeds44,102
Wine grapes5,800
Christmas trees3,600
Silage corn2,500
Tree fruit1,615
Berry crops1,535

Source: Yamhill Agricultural Water Quality Management Plan / Census of Agriculture, 2012. Nursery and greenhouse information was not included in the 2012 report.

Historically, groundwater and “surface” water — primarily rivers and streams — have been treated as unrelated. In fact, they are closely connected. Riverbeds are not impervious, like bathtubs. Water continues to flow through them largely because the ground beneath and around them is so saturated that it won’t hold any more. That’s why one of the best places to drill a well is near a river. That water-soaked ground is also what keeps the stream flowing through the dry months, as water seeps from the ground into the stream bed.  

But when groundwater levels drop, water from the river soaks into the ground. In years like this one, that contributes to low river flows. Yet wells pumping up groundwater are used as a backup source, when rights to draw directly from the river are cut off. Groundwater levels throughout the state have been dropping for the past 15 years, as lower-than-average rainfall has combined with heavy use.

“Groundwater has always been our savings supply in dry times,” Matter said.

But that savings is becoming depleted. Hydrologists say that by now, Oregon soils are so dry it will take years for them to recharge. Lower-than-average rainfall has contributed to that, along with low snowpacks. Timing of precipitation also makes a difference, Matter said.

“This is something we’ve been hearing about from climate scientists for a long time; you might get near normal precipitation, but if it comes in a different form at different times, you get a whole different hydrograph,” she said. Soil conditions affect how much rainfall penetrates the ground; so does rainfall rate. Rain falling at a rate faster than the soil can absorb it becomes surface runoff, even if the soil is dry.

Water law expert Randy Stapilus has suggested that, at some point, valley residents may have to reconsider how they use water.

“One of the questions is how water is used. Domestic users for example, don’t use the massive amounts of water that some others may use,” he said. Stapilus noted that “Irrigation, for example ... in many places uses a huge portion of the available water.”

The Agricultural Water Quality Management Area Plan notes: “The primary use for which water rights are issued in the Yamhill Basin is irrigation. The amount of water appropriated in the basin is 8,300 annual acre feet (one acre foot covers one acre of land with a foot of water), with 6,423 acre feet of this allocated for irrigation.”

One acre foot equals 43,560 cubic feet.

The water used for that irrigation “comes from several sources in the Yamhill Basin,” states the plan. “These sources include impoundments, groundwater, out-of-basin transfers and streams throughout the basin. Additionally, the Palmer Creek Water District Improvement Company diverts water from the Willamette River, and excess water is returned to the Yamhill. Presently, there are no further appropriations of surface water allowed in the South Yamhill River, and most other basins are fully appropriated in the summer,” the water management plan states.

Sweeney agrees that “Agriculture is going to need to look at how it uses water.”

But he thinks the Willamette Valley, comprised of some of the richest farmland known, should be reserved for farming, although he acknowledges that the conflict between farmers and other residents isn’t going to go away.

And not everyone is happy about the water used by agriculture.

In July, Yamhill resident Jeff Dunham went before the county commissioners to tell them that his well suffered when a new vineyard began drilling for water a few years ago. He fears that more vineyards, and more wells to irrigate them, will follow, possibly leaving him without water.

Vineyard Manager Allen Holstein, who has been growing grapes in the county since 1980, said that slightly fewer than half of the region’s grape growers irrigate, and that water conflicts depend, in part, on location.

For example, he said, “Wells in Dundee don’t yield a lot of water, but they’re dependable, and they get good recharge.” On the other hand, “The Yamhill-Carlton area is notorious for having water problems.”

Holstein said that increasing the number of wells, for all uses, inevitably leads to conflicts.

“The ground is like a big sponge, and the more wells you put into it to suck out the sponge, the less there is,” he pointed out. “The blame can’t be laid at the feet of the vineyard industry.”

Holstein said he believes “The solution is stored water, stored winter runoff or more cultivation, or both.

“In a smaller vineyard, it’s not practical to build a reservoir to hold runoff, but in a large vineyard it is, and most of them have, because we saw this coming a long time ago,” he said.

Opinions vary on the importance of irrigation to grape-growing, Holstein said.

“From our experience, we think it’s an important practice, but some of my colleagues disagree pretty strongly.”

There are a variety of ways to manage water and vineyard growth, and they require balancing different issues, Holstein said.

“In the future, grape growers could mitigate water with more cultivation, which has its own trade-offs and conflicts,” such as erosion, he said.

Erosion can be managed with cover crops — but those, too, can have challenges, Holstein said. Perennial cover crops between the rows can help reduce erosion — but also compete with the grape vines for water and nutrients. Holstein said he tends to use annual cover crops over the winter months and remove them in the summer, although he said there are other factors that play into the decision, such as the vigor of the grapevines, and noted that many of those decisions are made in the spring.

“It’s a balancing act with a lot of moving parts, and you have to make a decision without knowing exactly what the weather is going to do to either complement or antagonize your efforts,” Holstein said.

Sweeney said that if the climate continues to become warmer and drier, farmers might, at some point, abandon irrigated crops in favor of more lucrative dry-farmed crops.

But he said there are other possibilities. For example, he notes the 13 reservoirs along the Willamette River.

They are managed for flood control as well as other uses, and are emptied in the fall in anticipation of rainfall that, this year, never arrived. This summer, the Willamette, along with nearly every river in Oregon, is suffering extreme low flows and warm temperatures that are killing fish and other aquatic species, resulting in toxic algae blooms and forcing severe cutbacks to water rights.

Sweeney suggested that maybe reservoir use should be reconsidered.

“I think there has to be a re-examination of that … and maybe reallocate what it’s supposed to be used for,” he said. “Maybe there could be a forecast in mid-winter. They could see a dry spring coming, and they could store part of that water for later use in the summer months. I think that’s something we could do, and it’s reasonable. It would be good for everybody, and for the wildlife in the Willamette Basin system.”

Other options, he said, include building more impoundments to store winter rainfall, or water from swollen winter rivers, for summer use, or using drip irrigation to minimize water use.

“I bet you that will be something that will really be catching on,” Sweeney said.

Sweeney, who has served on the Soil and Water Conservation District board of directors for nearly 30 years, said water quality is also an important consideration.

Reducing irrigation to the bare minimum, so that water contaminated with sediment or pesticide residues doesn’t flow to waterways, is one important way of addressing both water quantity and quality, he said.

“Something all of us need to be aware of is that everything we consume eventually is going to come out, and end up in the watershed somehow,” he said. “We’re all downstream from a neighbor, so we’re all part of this together, and we all need to work together to reduce our impact on the watershed.”


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