Lands and Waters of Yamhill

Description of the current state of Yamhill County lands & waters with respect to conservation, working lands and parks.

General Description

Yamhill County is primarily a rural county but is feeling the effects of its proximity to Portland, its attractiveness as a retirement area, the rapid growth of its two  largest cities, McMinnville and Newberg, and the burgeoning wine industry.  


From 1990, Yamhill County’s population increased by over a third to more than 90,000 people. By 2020, the State of Oregon’s Office of Economic Analysis projects that Yamhill County’s population will see roughly a 40% increase — approximately 33,000 more people, totaling 120,000 people.  According to United States Census estimates, just over half of the county’s current populace lives in the two cities of McMinnville and Newberg, with the remaining residents living on farms and in smaller towns.


For a general overview of the natural resources of Yamhill County, see the Soil and Water Conservation District's Nature Resource Profile.

The Lands of Yamhill County

Located in the northern Willamette Valley, Yamhill County stretches from the Willamette River on the east up to the summit of the Coast Range on the west. About one-third of the area of the county is gently sloped valley bottomland, ranging in elevation from about 60 feet above sea level on the eastern boundary at the Willamette River to about 400 feet above sea level in the upper valleys of the tributaries of the Yamhill River.  The remaining two-thirds is forested uplands with elevations up to about 3,400 feet at Trask Mountain.  The higher elevations receive much greater annual precipitation (up to 160 inches) than the lowlands (40-60 inches).  Differences in elevation, slope, and precipitation, along with the historic role of fire on the landscape, have produced the diverse habitat types in Yamhill County. 

The Waters of Yamhill County

Most of Yamhill County lies in the Yamhill Basin Watershed.  Dozens of small creeks supply three sub-basins: North Yamhill, South Yamhill, and the Yamhill River main stem.  Uses include: fishing, swimming, boating, wildlife habitat, agriculture, domestic and industrial supply.  The Yamhill River is home to steelhead and a tributary to the Willamette River.  The rest of Yamhill County lies within the Chehalem watershed (and also a tributary to the Willamette River), a relatively intact wetland and floodplain system providing excellent waterfowl habitat.  

Water supply varies seasonally with high winter stream flows and low summer flows impacted by municipal and agriculture use.  With low stream flows, temperature, nutrient and bacteria concentrations increase, which can negatively impact wildlife. 

Eleven stream segments in Yamhill County do not meet state water quality standards for one or more of: bacteria levels, temperature, flow modification, dissolved oxygen, pH, or for presence of toxic materials such as pesticides.  These segments are listed by the Oregon Department of Environmental Quality (DEQ) under the Federal Clean Water Act as requiring action to improve water quality to meet state standards.

Conservation / Wildlife / Habitat in Yamhill

Yamhill County has the largest concentration of Oregon White Oak habitat remaining in the Willamette Valley.  Several Federal listed threatened or endangered species are found here including the Kincaid’s Lupine and the Fenders Blue Butterfly.  Other species are listed under the Federal sensitive species list (updated 1/10/2009) . Historically, oak savanna and woodland, upland and wet prairies were the dominate vegetation types.  Now these high priority ecosystems have all but disappeared.  


Diversity and acreage of natural wildlife habitats in Yamhill County was reduced as land was converted from natural forest and grassland to managed forests, cropland, homesteads, and urban areas.  Clearing of lands for urbanization and other developments continues to threaten sensitive plant and animal populations.  Invasion of non-native species, both plant and animal, are also reducing the viability of native species.

The following assembled courtesy of The Nature Conservancy in Oregon:

  • A map (pdf) of the Ecological Systems and High Priority Conservation Opportunities in Yamhill County, Oregon
    • detail map of north Yamhill County
    • detail map of south Yamhill County
    • spreadsheet crosstabs of acreage totals for each ecosystem by type of owner
  • map (pdf) of the Land Ownership and Key Oak Woodland Parcels of Yamhill County, Oregon
    • detail map of north Yamhill County
    • detail map of south Yamhill County
For background, see the Yamhill County Soil & Water Conservation District's Master Plan.
For the greater Willamette Valley, see the OR Department of Fish & Wildlife's Willamette Valley Ecoregion.
Federally listed, proposed, candidate species and species of concern under the jurisdiction of the Fish and Wildlife Service which may occur within Yamhill County, OR: list.

Working Lands in Yamhill

Rich soil, good climate, and refined production techniques combine in Yamhill County to produce high quality crops and timber.  Agriculture and lumber production are the leading industries in Yamhill County with agricultural income ranking from 3rd to 5th among Oregon counties at over $500 million annually.  About 1/3 of soils in the county are considered “prime agricultural land”.  Soils once thought to be only suited for pasture and timber production now support the thriving vineyard industry occupying many ridge-tops throughout the county.  


Since 1980, there has been a 12% reduction in cropland under production, significant changes in the crops grown, container grown and bare-root nursery plant production have become one of our largest industries, and animal agriculture has undergone major changes.  Working lands are impacted by development, and a generational transfer of lands is underway with a desire to preserve rather than convert lands. 

 

The local wine industry is a complete vertical industry around the value-added (winemaking and selling) component rather than a primarily a commodity (wine grape) industry.  The wine industry also generates significant tourist and international industry event-related income. There are currently over 225 vine- yards and 89 wineries in Yamhill County. Vineyards are both a threat to these ecosystems as well as a source of conservation ethic and support.

For more detail, see the Yamhill County Soil & Water Conservation District's Master Plan.

Parks & Natural Spaces in Yamhill

Yamhill County has special natural, scenic, cultural, ecological, and historic resources which are highly valued by residents.  The county provides pastoral scenic vistas of farming and nature close to many people.  But there is relatively little actual access to, or assurance of, long-term preservation these assets.


Yamhill County currently owns and maintains 17 parks and open space areas totaling just 126 acres.  Ten of the sites are developed, six are undeveloped, and one is leased.  Most sites maintained by the county need significant improvements, although some progress been made recently.  While representative of natural habitats and historic resources, the small size of these sites makes them marginally beneficial as conservation sites.

For more detail, see the Yamhill County Parks' Master Plan.

For city park systems, see Chehalem Park and Recreation District and McMinnville Parks & Recreation.

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Will Neuhauser,
Nov 6, 2008, 4:53 PM
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Will Neuhauser,
Nov 6, 2008, 4:52 PM
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Will Neuhauser,
Nov 6, 2008, 4:56 PM
Ċ
Will Neuhauser,
Nov 6, 2008, 4:56 PM
Ċ
Will Neuhauser,
Nov 6, 2008, 4:53 PM
Ċ
Will Neuhauser,
Nov 6, 2008, 4:59 PM
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Will Neuhauser,
Nov 6, 2008, 4:57 PM
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William Neuhauser,
Sep 22, 2010, 5:53 PM
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William Neuhauser,
Sep 22, 2010, 5:54 PM
Ċ
William Neuhauser,
Sep 22, 2010, 5:55 PM
Ċ
William Neuhauser,
Sep 22, 2010, 5:56 PM
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