GRANTS PASS — Contractors are on the cusp of removing a concrete dam that has been part of a Grants Pass Irrigation District canal blocking wild salmon migration for at least 50 years.
The Tokay Canal is located on Jones Creek, a tributary of the Rogue River, just east of Grants Pass. During the district's five-month irrigation season, the canal has meant a dead-end for juvenile wild coho salmon and steelhead heading down Jones Creek toward the Rogue River, and it has blocked adult fish heading back up Jones Creek to spawn.
The 8-foot-tall concrete structure backed the creek up at the confluence of two forks, forming a wall of sorts that allowed canal waters to cross Jones Creek during the irrigation season that runs from mid-May to early October.
But at times it blocked thousands of juvenile wild steelhead and coho, which are listed as threatened under the federal Endangered Species Act.
The canal's water instead will be piped beneath the creek beginning next irrigation season.
"It's a fish barrier in a coho stream," GPID Manager Dan Shepard says. "It behooves the irrigation district to get out of creeks like that."
The project is spearheaded by the Stream Restoration Alliance of the Middle Rogue, a group of watershed supporters and sport-fishing groups similar to watershed councils elsewhere in the Rogue Basin.
Construction crews already have prepped the site, but they were waiting this week for finalization of a U.S. Army Corps of Engineers permit for the dam's actual removal, says Dave Grosjacques, an alliance member working on the project.
The permit was being finalized this past week by Corps workers in Portland who were not subject to the federal government's shutdown since Tuesday. Grosjacques says he hopes the project moves forward today.
"We're just waiting for a phone call," Grosjacques says. "We were afraid the office would be closed and our permit would be just sitting there."
The Tokay Canal carries about 15 cubic feet per second of water from GPID's pumping plant for about five miles to feed about 400 GPID patrons in the north Grants Pass area.
The canal work is the latest of several concrete dams, culverts and other barriers that have been keeping wild salmon and steelhead from effectively seeding scores of miles of Rogue tributaries that are considered key spawning and rearing grounds.
GPID officials have no paperwork on when the structure was built, but the concrete formations appear to be post-World War II, Shepard says.
The concrete structure is three-sided and spans the creek just below where waters from the East Fork and West Fork merge. Six boards are placed in the center to block the flow and create a canal wall so the water can flow through the creek and return to the full earthen canal on the opposite side.
The boards are placed in the dam during the irrigation season, whose beginning often overlaps the spring migration of wild salmon and steelhead smolts headed from Jones Creek to the sea.
But the canal waters don't flow over the boards, and juveniles that don't escape before the boards are placed get trapped.
For the past seven years, the Middle Rogue Steelheaders, a Grants Pass-based sport-fishing group, has worked with Oregon Department of Fish and Wildlife biologists to capture these stranded fish in the canal, place them in buckets and release them downstream of the structure.
Some years, the volunteers have collected none, Grosjacques says. Other years, they have carried thousands of young fish to freedom, he says.
When the boards are removed, downstream passage is possible. However, the dam's lip is about 4 feet above the lower creek's surface, providing a barrier to migrating adults under all but high-flow events.
The project costs $170,000. GPID kicked in $29,000 for the piping work and $3,500 in other in-kind costs, Shepard says.
The Oregon Watershed Enhancement Board kicked in close to $21,000. Others contributing money to the project include the ODFW, the Middle Rogue Steelheaders, Patagonia and Pacific Power's Blue Sky program.
Reach reporter Mark Freeman at 541-776-4470, or email at firstname.lastname@example.org.