Working to save the Metolius River
Last updated 10/24/2023 at 10:05am
Over 30 years ago, biologists realized the Metolius River had a serious problem. As the Forest Service (USFS) moved toward "Ecosystem Management," they recruited botanists, including me, to look closely at plants in the National Forest. There was a strange striped grass taking over riverbanks and islands in the river. This grass was so aggressive it crowded out native plants that supported insects important to wildlife and fish.
It was Ribbongrass (Phalaris arundinacea var. picta), an ornamental plant found in horticultural magazines back into the 1800s. The story was, it was planted near a summer home, possibly in the 50s, and it expanded from there into wet habitats.
A maxim in invasive species management says that when the public notices a plant out of place, it's generally beyond control. And people did notice. In 2004, the Forest Service began more aggressive work on noxious weeds, (now termed invasive plants). People familiar with the river, including the Friends of the Metolius, asked what was going on with ribbongrass and why the Forest Service wasn't doing anything about it.
Controlling ribbongrass was a wicked problem, complicated by the outstanding features of the protected Metolius Wild and Scenic River, with pristine water quality, a stronghold for threatened bull trout, and over 100 homes drawing water from, or with wells along the river where water quality needed to be protected. Agencies and the Tribes were working hard to reestablish fish passage, hoping to see salmon spawn in the Metolius as they had for millennia before dams stopped the runs.
Nobody thought that controlling ribbongrass was going to be easy or even possible with all these concerns. People worried that ribbongrass control on a few acres would be so controversial that it would threaten approval of over 14,000 acres of invasive plant treatments on the Deschutes and Ochoco National Forests.
Luckily, the Friends of the Metolius (FOM) had our back and were willing to help. The lead was Pete Schay, a retired federal employee, who had experience with noxious weed control, and a winning personality. Pete remembered, "There was no clear way forward, but we were united in our desire to control the invasive riparian plants and restore native ones. We, the USFS, FOM, other agencies, land owners, and environmental organizations, were very nervous about messing around in the Metolius River. We progressed with caution. The Forest Service led the effort and FOM supported it in any way we could."
A big question was how to best control ribbongrass. Herbicides were known to be effective, and sometimes digging out the root system of the plant could help suppress it. Trials had also been done covering infested areas with black plastic for several years.
Pete found private landowners with infestations that wanted to help and were willing to have trials on their property. He covered a small island below the Camp Sherman bridge with black plastic. The FOM added a sign, explaining the project and why it was so important to protecting the Metolius. Pete was surprised by the reaction. "We found the Metolius summer home folks to be amazingly understanding. Most wanted action and restoration of the river. My fears of serious opposition were unfounded. We were on our way, but it was a long way, much longer than I anticipated."
It took eight years to complete the analysis and during that time the Friends, Forest Service, Jefferson County, and Mike Crumrine of the Oregon Department of Agriculture (ODA) kept testing herbicide combinations and strengths, digging the plant, and covering it with black plastic. We promoted the story on the radio and in print media.
One of the most difficult trials was proposed by the Sierra Club, to manually remove the plant. It was back-breaking work to pull ribbongrass clumps on a small infested river island. River rocks and mud came along with each clump, creating a cloud of sediment downstream and weighing down our bags of grass. A drippy pickup load was delivered to a dry gravel pit and covered with plastic to kill the plants. In an illustration of resilience, when the plastic was removed after two years we found ribbongrass growing again in this dry gravel pit! It was a tough plant.
When we finally had approval to use herbicides, we tested water quality downstream and proceeded slowly. The great news was that carefully spraying aquatic herbicides on the plants was very effective, there was little overspray into water, and after three years plants were virtually gone. I retired in 2016 with a tiny portion of the river treated but we had developed detailed maps of where ribbongrass and yellow flag iris grew.
Botanist Beth Johnson took over and got busy. She noted "Some people are still wary of any herbicide use at all, but when they see what we are doing and the success that we are having, they have been really supportive. We mostly have input from people wanting to make sure we know about a patch in one of their favorite areas so we can hit it for them before it expands."
The river is healing now.
Beth said, "It is so great to see healthy natives where we used to have weeds... some of the stretches along the river look completely clean now. We will continue to monitor those stretches."
There are some sensitive or dangerous areas that still need treatment, but Pete Schay summed it up: "It's a wonderful story of collaboration: Jefferson County, ODA, private owners, Friends of the Metolius, cabin permittees, and the USFS all pulling together to pull off this successful project. We know it will never be complete but we keep trying."