Coldwater Conservation Fund

Building Ecosystem Resilience on Sheep Creek: A Tributary to the Grande River in Oregon

Sheep Creek is a tributary to the Grande Ronde River and provides important spawning and rearing habitat for salmon and steelhead. But over the past few years, the Oregon Department…

Sheep Creek is a tributary to the Grande Ronde River and provides important spawning and rearing habitat for salmon and steelhead. But over the past few years, the Oregon Department of Fish and Wildlife has found no salmon redds (nests) and few steelhead redds in the reach of Sheep Creek on U.S. Forest Service (USFS) and U.S. Bureau of Land Management (BLM) land. Trout Unlimited, USFS, and other partners are engaged in an intensive, multi-year effort to restore, protect, and reconnect 4.5 miles of mainstem Sheep Creek floodplain and fish habitat in the headwaters known as the Sheep Creek Stream and Floodplain Restoration Project. In 2019, this project treated more than 10 miles of stream in the Sheep Creek sub-watershed.

A flash of reddish-pink shimmied across the gravel creek bottom and under the cut bank. I jumped across the stream, got onto my hands and knees, and peered through a rootwad into the pool below. Blue-green-silver. Black dots. Fading red. Chinooook!!!

Chinook salmon are perhaps the most iconic wildlife species of the Pacific Northwest. Whether it’s the billion-dollar commercial fishing industry dependent on these creatures, or the nutrients from their carcasses that help floodplain trees grow three times faster, or the gathering of communities for seasonal salmon feasts, these fish are deep in the lifeblood of this region, and the rivers that carry them are the veins.

But across their native range on the West Coast, Chinook population numbers are critically low. In dozens of streams like Sheep Creek and in river systems across Oregon, Trout Unlimited (TU), the oldest and largest sportsmen’s organization dedicated to conserving and restoring native trout and salmon and their watersheds in North America, is working with USFS, BLM, National Oceanic and Atmospheric Administration (NOAA) Fisheries, and other state and federal agencies, tribes, and non-governmental organization partners to reverse this trend.

USFS Fish Biologist Sarah Brandy and I were walking along Sheep Creek on that hot July 2018 day when I spotted the Chinook. This important tributary to the Grande Ronde River originates in forested headwaters high in the Elkhorn Mountains and flows through Blue Mountain Meadows on USFS and BLM land before meandering through Tony Vey Meadows, where it meets the Grande Ronde River. That day, we walked the whole 4.5-mile mainstem project reach to plan for our 2019-20 restoration project.

As excited as we were to see an adult Chinook, this was the only adult fish sighting of 2018. This sad fact strengthened our resolve to restore, protect, and reconnect this system.

In the Blue Mountains, these meadow systems are the heart of the landscape. In good condition, they enhance groundwater exchange in their spongy valley bottoms, creating a hotbed for biological diversity and resilient habitat for fish and wildlife. But the combined effects of past land use practices have oversimplified these once- complex systems, degrading their natural water storage capacity that is critical in ensuring late-summer stream flow and water temperatures cool enough to support salmon and steelhead.

The Sheep Creek meadow system once functioned as a vast network of channels and pools manipulated by beavers, and historical aerial imagery and modeling reveal a network of multi-threaded channels and a floodplain still capable of acting like a giant sponge.

When our project began, Sheep Creek was a single-thread incised channel, lacking the riparian shrubs needed to support beaver use. Rather than diverse water-dependent floodplain communities spanning the meadow, we found a lack of in-stream woody debris and plant species that require dry conditions dominating much of the valley bottom during our project planning and pre- treatment monitoring process. Long, straight riffles were common where there should have been a variety of pools, riffles, glides, and beaver ponds.

In order to slow the flow of water through the system and reconnect the floodplain, we employed a variety of tools and tactics. We contracted a helicopter to transport more than 2,000 trees from nearby roads to the stream side to improve transportation efficiency and decrease our impact on the meadow floor. This task included placing more than 80 trees longitudinally in the stream bottom to increase habitat complexity. We used two “Tonka Toys” (excavators) to place more than

200 large wood structures, 150 loose pieces of floodplain wood, and 50 whole trees in the channel for habitat complexity, channel aggradation, sediment sorting, activation of historic side channels, and backing up water to increase the channel’s wetted width.

Finally, we piloted a new initiative to work with U.S. service veterans, who placed wood in-stream using hand-based logging equipment, set up in primitive camps for four-day hitches, and learned about careers in natural resources. This crew placed more than 40 structures in the mainstem project and then moved to the headwaters to restore an additional 5+ miles of stream and meadow habitats (see article insert “Fish Condos”).

Long term, our restoration treatments in the main channel should aggrade gravel and sediment to the point where the stream bottom rises to the height of the meadow and begins to create a multi-threaded channel network. When we walk through the system now, we see long, deep backwater pools where wood structures and beaver dam analogs are backing up water. The wetted width of the channel in many places at low flows has expanded by more than 10 feet. The cover and shade for fish habitat has increased exponentially. The stream velocity has decreased significantly, leading to more groundwater interaction with the main channel. Several weeks after the mainstem project work, groundwater was found bubbling up in several places far from the channel’s edge. This desirable phenomenon is known as hyporheic exchange, the mixing of surface and shallow subsurface water through porous sediment surrounding a river.

The project team is using an adaptive management plan to guide treatment techniques on this stretch of stream. Future treatments will be driven by monitoring results. The team is experimenting with the use of more than 30 years of satellite data to measure trends in the meadow vegetation, combined with ground- based vegetation transect monitoring from the USFS Ecology Team.

Seeing that lone fish return to Sheep Creek on that July day is a reminder that our Grande Ronde River salmon and steelhead runs are critically diminished. Oregon’s 13th Governor, Republican Tom McCall, once said, “If the salmon and steelhead are running, then as far as I am concerned, God knows that all is well in His world…The health of the environment is good if the salmon and steelhead are around. It is that simple.”

Projects like Sheep Creek are an important step in the process of bringing salmon and their habitats back to health. However, we need all hands on deck in our human communities to make abundant salmon in our home rivers an unforgettable sign of the seasons once again.

Additional media featuring the Sheep Creek Project:

Project Partners: U.S. Forest Service, U.S. Bureau of Land Management, Grande Ronde Model Watershed, and NF John Day Watershed Council. Project Funders: Bonneville Power Administration, Oregon Watershed Enhancement Board, and U.S. Bureau of Reclamation.

By Levi Old.