Little fish get a bigger pond

Oregon chub are native only to the Willamette River valley, and since 1993 they have been listed as threatened under the federal Endangered Species Act. The fish prefer off-channel habitats with minimal or no flow and an abundance of vegetation: beaver ponds, oxbows, backwater sloughs, shallow tributaries and flooded marshes. But in the past 150 years, the amount of such habitat has shrunk as the Willamette River has been dammed to control against flooding, cleared of snags to facilitate navigation and drained of wetlands to increase the amount of agricultural land.

The East Fork Minnow Creek, off Oregon 58, was home to one of the largest naturally occurring chub populations until a combination of factors, including severe floods in 1996, choked its ponds with sediment. As part of ODOT's commitment to replacing habitat if construction causes any to be lost - referred to as conservation banking - the agency took advantage of this suitable starting point to rehabilitate some habitat for Oregon chub.

Bridge program staff and ODOT maintenance crews collaborated with colleagues from the Oregon Department of Fish and Wildlife to isolate the work area and clear fish from the small channels in the work area, saving a total of 156 Oregon chub, 261 red-side shiners and 126 speckled dace. Next, the maintenance crews removed the sediment that was making the pond uninhabitable. On the most productive day, they took about 200 yards out of the pond - approximately 40 five-yard dump trucks' worth.

Finally, they pushed four large logs, two small trees and two root wads into the ponds and made the shoreline more complex by excavating small indentations that will create more vegetation. The chub enjoy all these features as cover when they're feeding, reproducing and nesting.

Now the enhanced beaver ponds and creek give the fish a home just like the one they grew up in.

Cutthroat trout get a step-up

Black-spotted cutthroat return to their home waters to spawn, and for some, home is the Willamette River and its tributaries. But in 2009, when construction began on the new Interstate 5 Willamette River Bridge project, the environmental team noticed the fish that approached the confluence of the Augusta Creek tributary and the Willamette River were stopped by a huge culvert, 400 feet long, which opened six feet above the river. The trout were able to access the remote stream above only at limited times of the year because the culvert was too high to jump to when water was low.

One great benefit of the scope of the bridge program has been our frequent contact with our counterparts in natural resource agencies. The Oregon Department of Fish and Wildlife first encouraged ODOT's contractor to extend the culvert to provide the trout with additional access to the area at the downstream end of Augusta Creek, under Franklin Boulevard, during construction and bridge demolition. But the cutthroat continued to struggle during migration, so the team decided to build a temporary fish ladder.

There are many kinds of fish ladders, each designed to accommodate certain types of fish. ODFW recommended a Denil design because cutthroat trout are strong swimmers that prefer to swim upstream in rapid water. The Denil fishway looks and works something like an escalator. The ladder - made up of a staircase of baffles, like steps filled with water, on one side - helps fish travel upstream. A flat metal chute on the other side allows the rest of the waterway, and even an occasional fish, to flow downward.

The ladder was only temporary because the culvert wasn't needed once Augusta Creek was restored to its native channel after construction finished. But in the meantime, even fish were able to maintain their mobility in the work zone.

Log housing

Salmon and other fish like having dead trees in their rivers. The trunks cast shade that cools the water. The pools that form underneath make good rearing habitat for young fish. The tree branches catch the leaf litter and needles that are food for everything from plankton to bugs, which in turn feed the salmon.

The bridge program found several occasions to contribute to log housing for fish. On Oregon 38 near Cottage Grove, replacement of five bridges required removing approximately 300 trees. But after the contractor cut down or uprooted the trees, ODOT and the Oregon Department of Fish and Wildlife transported them to the Umpqua River basin to improve the river's ability to host salmon. The 20 truckloads of trees helped restore 13 miles of Paradise Creek and Brad's Creek.

The project benefited not only fish but the businesses around the Umpqua River basin. ODFW contracted with logging companies to haul and place the felled trees and with landowners to stockpile those that were awaiting placement.

In January 2011, as the bridge program was replacing the Interstate 84 Sandy River Bridge near Troutdale, a storm hit over the Martin Luther King Jr. holiday weekend. A cascade of logs and root wads washed down the river, where they backed up against the bridge piles.

Crews immediately dislodged as much woody debris as could flow downstream safely, so it could form habitat naturally. Then they removed and donated nearly 40 truckloads of the rest to ODFW, which transferred them to the Freshwater Trust, a nonprofit group. The trust created and restored habitats for rainbow trout and chinook and coho salmon throughout the Sandy River Basin.