By Tom Morphet
A large, specially designed culvert installed last week is expected to
ease the migration of salmon and cutthroat trout that navigate through the west part of
town to a stream just south of Sixth Avenue and Union Street.
The culvert will allow mature cutthroat – and possibly coho salmon
– to cross Union and reach approximately a half-mile of pristine stream habitat near
the Mount Ripinsky hillside.
"It’s fantastic. We’re really excited and
thankful," said Emily Seward, development director of the Takshanuk Watershed
Council.
The $150,000-project has been discussed more than a decade, predating
formation of the council. It replaces a dog-legged section of 30-inch culvert that ran
about 400 feet with a 72-inch pipe that runs in a straight line 300 feet. Thirty-inch-high
baffles that serve as dams are located every eight feet along the pipe.
"It creates a series of pools so fish can jump in little stages
and jump in between (baffles). Jump and rest. Jump and rest," said state Department
of Transportation design manager Kirk Miller.
The dams also serve to hold water, ensuring passage when water flows
are low. When flows are high, the resting pools make for easier passage than swimming into
water of a sustained velocity.
Funding for the project was secured by state Rep. Bill Thomas,
R-Haines, several years ago. The work had been postponed to coincide with paving and
associated culvert and utility work along Union Street.
Cutthroat trout like small, shallow streams for spawning and ones bound
for Union Street find their way up Sawmill Creek through a series of roadside ditches and
culverts, including one that runs beneath DOT’s maintenance shop yard on Main Street.
"They like these little, shallow, nothing streams. It’s their
preferred habitat for spawning. It’s amazing how they work their way up there,"
said Rich Chapell, Haines sport fish biologist for Fish and Game.
Biologists have found juvenile cutthroat north of Union Street, but
don’t know if those trout have migrated through the aging 30-inch culvert buried as
deep as 20 feet under the old borough maintenance shop, or whether they are a land-locked,
resident population.
Mature coho salmon and Dolly Varden use sections of stream downstream
of the culvert, and borough water and sewer operator Scott Bradford said he’s even
seen spawning coho above Union Street.
Sport fish biologist Chapell said he was unaware of coho spawning above
Union, but wouldn’t rule it out. Large returns of coho can prompt the fish to find
new streams to spawn, he said. "It seems kind of shallow for coho spawning but in
2002 and 2003, we had coho spawning everywhere."
Besides making way for fish, the size of the pipe also allows crews to
enter it to clear potential obstructions, DOT officials said. The former, smaller culvert
plugged at least once, flooding the adjacent, historic McRae House.
The culvert complements work by the watershed council, which moved the
stream out of a roadside ditch and reduced its grade near Sixth Avenue and Dalton Street,
Seward said.
Seward’s group is continuing efforts started almost 20 years ago
to rehabilitate Sawmill Creek, a waterway that’s been filled and ditched during a
century of residential and commercial development west of downtown. She said her group was
excited to see how the culvert worked, including whether mature coho would use it.
"Hopefully we’ll have a big coho year soon and we can test the water,
literally."
The new culvert was designed specifically for the site, using stream
flow rates to determine its proportions. There’s at least one other culvert like it,
in use under the Haines Highway in the upper valley, DOT officials said.
The existing culvert will be plugged and otherwise mothballed, they
said.
