Slayden/LanPacific/Providence

Rogue River Dam Removal Starts Phase Two

Floor-to-ceiling windows allow passersby to view three 20 by 20-foot murals at Providence Medical Group’s North Portland Clinic. (Photo courtesy of Mahlum)

Grants Pass, Ore. — Slayden Construction, Stayton, Ore. began demolition of the north sixs bays of the Savage Rapids Dam located on the Rogue River near Grants Pass, Ore. The project is one of the largest dam removal efforts in the country to date.

The 39-ft-high, 500-ft-long dam was built in 1921 by the Grants Pass Irrigation District (GPID) only for irrigation and provides no electricity or flood control.

Fish passages in the dam were substandard and sometimes completely blocked fish passage. In 1991, Water Watch, a national environmental non-profit, tried to block GPID’s water rights permit. From 1995 to 2000 the district responded with several lawsuits, but when the federal government declared the coho salmon an endangered species, “a judge sat all the parties down to solve the problem with a consent decree, which included a lobbyist who would get money for the project,” says Bob Hamilton, Bureau of Reclamation activity manager. Dam removal is expected to open up 500 miles of additional spawning grounds to salmon and steelhead. Eventually the salmon run could increase by 117,000 fish.

Slayden Construction Group, Stayton, Ore., is in charge of the $28-million project to remove the dam. It started in 2007, by building a soldier-pile cofferdam to stem the flow downstream of the irrigation pumps. “Using a soldier pile is a bit old-school,” says Darren Funk, Slayden project manager. The contractor thought driving sheet piles into the base would be too hard because the rock under the river is an exceptionally hard type of granite.

Silt behind the dam is not expected to be a major factor. “We used turbidity curtains and arranged the construction sequence to minimize turbidity to avoid damaging the irrigation intake’s ability to draw water from the river,” Funk says. “We also modified the fish ladder entrance so work would not affect it.”

When the river is diverted into the original river channel in October the irrigation intake structure will be out of service and protected by structural steel debris barriers. Slayden will excavate a pilot channel through the existing lake bed sediment to allow the river to make its way through the original river bed to minimize sediment travel and allow fish passage. The majority of river sediment will be displaced during the winter when the irrigation system is not in service. “Future maintenance dredging of the intake structure may be needed and has been addressed by the irrigation district,” Funk says.

There were contingency plans in place should the river flows exceed the radial gate’s 4,000-cu-ft-per-second diversion capacity. But reduced snow pack and little spring rain allowed work to resume in April.

The dam will be mechanically removed. Project completion is expected in December.

Design Firm Earns 8(a) Certification and access to more jobs

Portland — LanPacific, a multidisciplinary engineering firm, recently received 8(a) certification from the Small Business Administration’s (SBA) Business Development Program. LanPacific is one of only two engineering firms in the state of Oregon to receive the designation.

The 8(a) certification provides LanPacific with greater access to federal architectural, engineering and construction contracting opportunities.

While LanPacific has served public agencies and partnered with other 8(a) firms in the past, Principal Erik Esparza sees the certification as an opportunity to further diversify LanPacific’s market base into even more agencies in the federal arena. “Moreover,” Esparza states, “it’s a vehicle that transcends competitive attitudes and creates teaming opportunities.” This in turn creates more jobs and strengthens the nation’s economy – a key SBA objective.