Pro-conservation groups this week released back-to-back studies charging that Measure 37 threatens high-value Willamette Valley farmland and Oregon's growing wine industry.

The studies, conducted by Environment Oregon and the American Land Institute, also claim that the changes proposed in the Nov. 6 ballot Measure 49 would fix the problems.

"When voters considered Measure 37 in 2004, what it would do was a guessing game," reads the American Land Institute report. "The guessing game is over."

The American Land Institute report, written by Henry Richmond, Portland attorney and co-founder of 1000 Friends of Oregon, found that 61 percent of Measure 37 claims were located in the Willamette Valley.

That's where the Environment Oregon report picks up.

While the Willamette Valley only makes up 9.5 percent of the state's total agricultural land, the report said it makes up about half of Oregon's "high value" farmland, where the greatest number of Oregon wineries are located.

"Nearly one in seven acres of land subject to Measure 37 claims qualifies as high-value potential vineyard land," according to the Environment Oregon report.

Measure 37 claims allow land owners to seek land use waivers or monetary compensation if property values are reduced because of land use regulations.

Among Measure 49 provisions are a limit on the number of lots allowed on high-value farm or forest land, or where groundwater use is restricted. The measure also demands a more accurate tally of how land value was reduced.

Benton County claims comprise more than 10,500 acres. County planners say the claims increase the potential for residential development by 50 percent.

Willamette Valley claims total more than 266,000 acres. Washington County lists the greatest number of acres impacted by Measure 37 at 62,246. Multnomah County has the smallest number of affected acres with just 4,024.

Both reports are largely based on a database of Measure 37 claims built and monitored by Portland State University's Institute for Metropolitan Studies.

The nonprofit advocacy group 1000 Friends of Oregon focuses on land use issues. Environment Oregon is the environmental activism arm of the Oregon State Public Interest Research Group, a public health lobbyist organization.

Arguments against Measure 49 - primarily voiced by Oregonians in Action, a property-rights advocacy group - contend that it takes the teeth out of Measure 37 and brings back land use regulations voters nullified through its passage.

Reporter Matt Neznanski can be reached at 758-9518 or matt.neznanski@lee.net.