Trail Awash In Troubles Flood Damage Costly; Funding Source Unknown

It will cost about $366,000 to repair flood damage to the Centennial Trail and ensure it doesn’t happen again, an engineer estimates.

About 550 feet of trail between Flora and Barker roads in the Valley was “totally destroyed and will require a complete rebuild,” David Larsen wrote in his report to Spokane County parks officials. Another stretch - more than one-third of a mile - suffered “heavy erosion and bank washouts.”

No one knows where the county will get money for the work. The trail remains open, though it is too rough in places for skating or bicycling, said Wyn Birkenthal, county parks director.

Some of the worst damage was to part of the trail repaired after 1996 floods at a cost of $73,000. Those repairs were lost when the churning Spokane River crested in mid-May during the fourth-highest flow ever recorded.

The environmentally sensitive techniques used to make the repairs were not strong enough to withstand the torrent, wrote Larsen of Taylor Engineering Inc.

Larsen, who could not be reached for comment late Wednesday, recommends erosion control methods that may not be approved by the state Department of Ecology.

“Taylor Engineering is sensitive to the ecological nature of the trail and the river,” he wrote. But “in order to protect against future damage … masonry walls, gabion baskets or keyed riprap should be installed.”

Gabion baskets are wire cages filled with rocks. Keyed riprap are walls of concrete or rock.

Although they were used in a few scattered places where the riverbank is especially steep, Ecology advises against such techniques because they destroy shoreline habitat and can cause worse flooding downstream.

The damaged section of trail originally was built with wooden retaining walls, said Birkenthal. The soil washed out from behind those walls during last year’s flood, undermining the asphalt trail.

When the damage was repaired, Ecology required that the county use “earth pillows,” biodegradable fabric filled with soil and small rocks. Native shrubs were planted on the pillows, but didn’t have a chance to take firm root before last month’s flood.

Such methods work well to protect banks from back eddies and gentle lapping, “but accomplish little when subjected to high-velocity river flows,” wrote Larsen.

Doug Pineo, shorelines specialist for Ecology, was out of town Wednesday and could not be reached for comment.

Birkenthal said the county has applied to the Federal Emergency Management Agency for money to cover 82.5 percent of repair costs. He said there’s no telling whether that request will be approved.

The trail is managed cooperatively by the city of Spokane, Spokane County and the state of Washington. The county will ask both the city and the state to help pay for repairs, Birkenthal said.

At first blush, the prospects don’t look good.

The state Parks and Recreation Commission has a $34 million list of repairs needed in various state parks, and has only about $5 million a year available to do the work, its director said in a December interview. The agency is spending about $300,000 repairing a footbridge in Riverside State Park - a project it had asked the nonprofit group Friends of the Centennial Trail to fund.

The city spends 8 percent of its budget on parks, compared to less than 1 percent in the county. It is not obligated to spend money on projects outside its boundaries.

, DataTimes ILLUSTRATION: Color photo Map of area damaged by flooding