SALEM — Most new wells in Oregon are drilled where groundwater is already at risk of depletion, potentially aggravating conflicts among irrigators, according to state water regulators.

In the past decade, about 80% of applications for groundwater permits were in “areas of concern” or “significant concern” for declining aquifers and other groundwater problems, an agency study found.

Roughly 80% of those applications were approved by the state’s Water Resources Department, the study said.

One-third of the “significant concern” areas identified in the OWRD’s analysis aren’t currently subject to regulatory groundwater restrictions, the report said.

The report’s findings were recently met with consternation by some members of the Oregon Water Resources Commission, which oversees the agency.

The problem is reminiscent of falling Chinook salmon populations in the Willamette River, which some consider the “best studied extinction ever,” said Joe Moll, commission member and executive director of the McKenzie River Trust.

“I kind of fear we have a similar situation where we’re watching something get worse. We’re kind of working but we’re somewhat limited, i.e. helpless,” Moll said during the commission’s most recent meeting.

Under Oregon water law, regulators are limited in their ability to reject permits for new wells, said Justin Iverson, OWRD’s groundwater section manager.

For example, wells must generally be within a mile of a stream or river to trigger concerns about substantially interfering with surface waters, he said.

Similarly, new wells are only considered to interfere with existing ones in limited circumstances, Iverson said. “There is a fairly high threshold for finding injury.”

Applicants are often “savvy” enough to know which locations are more likely to be approved for drilling, he said.

“The statutes say that we’re going to presume that a new application is in the public interest, but that’s a rebuttable presumption,” Iverson said.

Permitting entities must always make decisions based on “imperfect information,” but the study indicates that Oregon may not have the correct standards for approving groundwater applications, said Meg Reeves, retired general counsel for Oregon State University and the commission’s chair.

“This does raise the questions for me as to whether we have drawn the line in the right place as to whether we would act to limit further appropriation,” she said. “I hope we’ll be able to find a way to do something with this information that would help us prevent further drawdown.”

The OWRD’s study, which has mapped the state’s areas of concern for groundwater, is intended to “stimulate conversations” with stakeholders and may discourage drilling in problem areas, Iverson said.

The analysis will also help prioritize aquifer monitoring and may indicate where the agency should re-evaluate the boundaries of groundwater restricted areas, he said.

For example, some wells next to the Mount Angel Groundwater Limited Area are showing declines similar to those within its boundaries, said Ben Scandella, OWRD’s groundwater data chief.

“This is an example of how this tool can help us see areas where the existing boundaries of groundwater restricted areas may have been appropriate when they were created but don’t necessarily reflect the current conditions,” he said.

The agency’s study does have a “data availability bias,” in that it focuses on areas where irrigation is the most prevalent, Iverson said.

Areas of concern are also measured by township, a 36-square-mile unit of land measurement in which groundwater conditions may vary, he said.

The map will be incrementally improved as OWRD incorporates more data in the future, Iverson said.

“We wanted to make an objective and repeatable evaluation,” he said. “This groundwater concerns map is going to be easily updated over time and we fully intend for it to be a living map as more information is brought in.”