Scientists and policy makers gathering in Southern Oregon this week will look for ways to restore the ecology of the Klamath Basin so both salmon and farming can thrive.

GRANTS PASS — Scientists and policy makers gathering in Southern Oregon this week will look for ways to restore the ecology of the Klamath Basin so both salmon and farming can thrive.

More than 300 people were expected Tuesday for the start of the weeklong conference in Medford. It was organized by the U.S. Geological Survey and NOAA Fisheries Service to share the latest ecological science on the Klamath Basin and chart directions for new research that will help inform a $1 billion restoration plan that includes removing a series of hydroelectric dams that block salmon.

"I don't think we will be able to solve this problem without the science underpinnings the decision makers are going to need," said Leslie Dierauf, USGS regional executive for the Northwest.

"There has been a lot of research done, but it's piecemeal," she added. "We can't do science in a vacuum anymore. It has to be really applicable."

The Klamath River descends from the Cascade Range in Oregon through Northern California to the Pacific Ocean north of Eureka, Calif.

It was once the third most productive salmon river on the West Coast, but after a century of mining, logging, overfishing and agriculture, it is a shadow of itself.

The crisis reached a peak in 2001, when the federal government had to shut off water to farmers on a federal irrigation project straddling the Oregon-California border to protect threatened salmon during a drought. The next year, after irrigation was restored, tens of thousands of salmon died in low and warm water conditions.

The secretary of Interior, the governors of Oregon and California, and PacifiCorp, the owner of the dams, have come to an agreement in principal to remove the dams starting in 2020.

An agreement between farmers, salmon fishermen, American Indian tribes and conservation groups is expected to be signed later this month that lays out the terms of the $1 billion restoration project, including how to divide scarce water between farms and fish.

Greg Addington of the Klamath Water Users Association, which represents farmers on the irrigation project, said the spirit of cooperation as well as the science have come a long way.

"Five years ago, we would have been going over there in battle mode about having to argue about my science vs. someone else's science," Addington said. "I'm comforted by the fact that I don't feel the need to defend or argue about anything over there. This is driven by the work in the settlement with the other stakeholders."

Glen Spain of the Pacific Coast Federation of Fishermen's Associations, which represents salmon fishermen who have seen their catches plummet in recent years as salmon stocks have declined, said the agreement assures that restoration will be driven by the best science.

"Science is an integral part of everything we do from dam removal to putting water back in the river to the smallest habitat restoration projects," he said.

Jack Williams, chief scientist for Trout Unlimited, said it will be important to monitor fish populations, water quality and other factors as the restoration progresses.

"Monitoring is listening to the land," he said. "We have to be good listeners to what this basin has to tell us as this experiment unfolds."

On Friday, Dierauf said she planned to build on the relationships developed at the conference to chart directions for new research that will be specifically intended to help state and federal policy makers make decisions.

"Without the appropriate science to back it up and help the managers make their decisions, it's going to be a crapshoot," she said.