Wednesday, June 10, 2015

Work Starts On I90 Wildlife Overpass

Geese using the Gold Creek wildlife underpass
The project to improve Snoqualmie Pass has already included building four underpasses to let The Yakima Herald says crews broke ground yesterday on the state's first freeway overpass for animals.
animals get from one side of the freeway to another. Soon, wildlife will have another option.

The 150-foot-long structure is expected to carry black bear, cougar, deer, elk, squirrels, mice and lizards. When finished, the section of I-90 from Hyak to Easton will have more than 20 underpasses and overpasses engineered for wildlife. Dozens of small culverts will also be rebuilt to allow easier passage.

Wildlife cameras are already recording deer, ducks, coyotes and river otters using the four existing wildlife underpasses.

From an engineering standpoint, it wasn't that tricky to lengthen bridges to create expansive undercrossings and enable streams and wetlands to meander naturally, according to project engineers.
For instance, the old bridge at Gold Creek, near milepost 55, was only 150 feet long and surrounded by embankments that animals couldn't navigate. The new version, finished last year, includes a 1,100-foot span that allows the creek to flow freely underneath and provide upstream passage for fish, like bull trout. The expansive opening also preserves wetlands and opens up a natural flood plain for Keechelus Lake. A separate undercrossing provides year-round passage for land animals, even when the lake is high.

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About SRTC

SRTC is the federally designated Metropolitan Planning Organization (MPO) for Spokane County. Urbanized areas with populations exceeding 50,000 people are required to have an MPO. SRTC was formed to address the county's transportation planning needs. It provides coordination in planning between the public, cities, small towns, the county, the state, transit providers, and tribes.

SRTC offers services including transportation monitoring, transportation modeling, census information analysis, travel demand forecasting, historical traffic count analysis, geographic information systems, and trip generation rates.