Diversion Dam Removal Above Lake Billy Chinook Opens More Habitat For Deschutes Salmon, Steelhead
Sep 12, 2014
The Columbia Basin Fish & Wildlife New BulletinAnother of the many human-built obstacles to salmon and steelhead passage up and down central Oregon’s Whychus Creek is being removed this late summer with the deconstruction of an irrigation diversion dam just above the town of Sisters that has long helped wet Pine Meadow Ranch fields and pastures.
The end result is that more water will be left in the stream for reintroduced salmon and steelhead, and the same amount of water will be available to irrigate on the ranch due to a newly installed delivery system that is considerably more efficient.
“The ranchers are winning; the fish are winning,” said project manager Mathias Perle of the Upper Deschutes Watershed Council.
Whychus Creek’s headwaters are high up in the Three Sisters Wilderness Area. It winds down out of the Cascade Mountains, through the town of Sisters and then through canyon lands and into the Deschutes River, a tributary to the Columbia River. Whychus’ 40-mile run ends just above Lake Billy Chinook, a reservoir on the Deschutes created by Round Butte Dam.
Portland General Electric and the Confederated Tribes of Warm Springs completed a new fish passage system that allows salmon and steelhead to get past Round Butte and two other dams just downstream for the first time since 1968. The utility and tribes now co-own the complex of dams.
The Deschutes fish passage facility has been in operation since December 2009. The tower creates currents in Lake Billy Chinook that attract juvenile fish migrating downstream. Fish are collected and transported below the Deschutes River dams to continue their journey to the Pacific. On their return, adult fish enter a fish trap below the hydro projects and are moved above the dams to complete their migration cycle.
Steelhead and chinook salmon had historically ranged up the Whychus to spawn. In anticipation of the construction of the dam passage facilities, the two species were reintroduced to the basin, released as juvenile fish into the drainage beginning in 2007.
“Chinook and some steelhead have made it back,” Perle said, while admitting that the run restoration is still “in its infancy.”
Pine Meadow Ranch is a 200-acre farm located along Whychus Creek immediately upstream from the city of Sisters with surface water rights dating back to the late 1800s.
Since the 1800s, the ranch has obtained its irrigation water from a point of diversion located on Whychus Creek approximately one mile upstream from the ranch on federal land managed by the Deschutes National Forest.
The diversion has been re-located and re-constructed at various times over the last century but, since the 1990s, the diversion has consisted of a six-foot-high concrete dam that is a complete barrier to fish migration and includes an unscreened diversion. The dam blocks access to approximately 13 miles of upstream spawning habitat.
Perle noted that well into the 1990s, flows in the creek at some point in late summer dropped to zero in one out of every three years. Past agreements and the one made with Pine Meadow are expected to boost flows to a minimum of from 20-30 cubic feet per second throughout the season.
Work over the past decade helped build flows back “one cubic foot at a time,” Perle said.
“It’s really a reflection of the community as a whole,” which has embraced the overall Whychus restoration effort, Perle said.
The Pine Meadow agreement involved the purchase a portion of the ranch’s senior water right and dedication of that portion to in-stream flows.
“It’s permanently protected,” Perle said.
He said an upstream log structure is the lone remaining barrier on the Whychus. It makes upstream passage for spawners difficult, though not impossible. Negotiations are ongoing regarding removal of that log irrigation structure.
The ranch has already switched from a delivery system that used an unlined, canal to a pump-fed pivot irrigation system, which now pulls water from the creek downstream of the dam.
The project, including dam removal, floodplain habitat restoration and on farm components, is estimated to cost about $2 million.
Partners in the project are:
-- Upper Deschutes Watershed Council
-- Pine Meadow Ranch
-- Deschutes River Conservancy
-- Oregon Watershed Enhancement Board
-- Pelton Round Butte Fund
-- Confederated Tribes of Warm Springs
-- Nat’l Fish & Wildlife Foundation’s Columbia Basin Water Transaction Program
-- Nature Conservancy
The project will be implemented in two phases completed in 2014-2015 and will focus on improving conditions in this area. It will:
-- remove the existing irrigation diversion dam that is a complete barrier to fish migration, opening migratory access to 13 miles of upstream habitat;
-- eliminate the existing unscreened diversion by moving the diversion downstream and installing a pump and fish screen;
-- improve fish habitat for redband trout, steelhead trout and chinook salmon by implementing a 170-acre floodplain restoration project along approximately 1.25 miles of Whychus Creek in the vicinity of the dam;
-- restore late season in-stream flows by restoring one cubic foot per second (cfs) of senior water right permanently in-stream.
The Whychus Creek watershed historically provided some of the best spawning, rearing and/or migration habitat for redband trout, spring chinook and summer steelhead in the area upstream of where the Pelton Round Butte dams were build. Fish passage facilities were built into the dams but did not work as well as planned, particularly for juvenile fish trying to find their way downriver.
The dam owners are continuing to implement an anadromous fish reintroduction program to bring fish back. To date more than $120 million has been invested in reintroduction with the long-term goal of achieving self-sustaining salmon and steelhead populations above the Pelton Round Butte dams.
With the historic reintroduction under way, efforts in Whychus Creek are focused on restoring the physical and biological conditions necessary to support successful salmon and steelhead spawning. Most of the work in the Whychus Creek watershed is conducted as part of The Deschutes Partnership, a consortium of organizations working together to support successful reintroduction efforts.
Restoration priorities include:
-- restoring a more natural hydrograph (i.e., increased summertime streamflow);
-- providing fish passage and screening at dams and/or diversions; and
-- protecting and restore a healthy stream corridor (including protection and/or restoration of wetlands, in-stream habitat, riparian and floodplain areas).
For more information about Whychus projects go to:
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