Benton CountyOre.
Including engineering and permitting, the project unfolded over …
Improving rural road safety
To accommodate the meandering creek below, the road above formed an abrupt 90-plus-degree angle. Thus, although it only accommodates an estimated 50 vehicles daily, Norton Creek Road’s blind spot made for some close calls between passenger vehicles and heavy logging and farm trucks.
“We really smoothed out the curve,” says Wheeler, indicating that the length and placement of the culvert allowed the roadway to be realigned to about a 45-degree curve. “It’s a nice easy transition over the culvert now.”
The department even found a way to offset material costs.
The Oregon DOT (ODOT) had soil fill material to remove from a nearby state highway project. Six hundred yards of fill dirt was imported to the county’s project site by an ODOT contractor at no cost to the county. This intergovernmental collaboration benefited state and county residents by reducing costs on both projects.
Benton County took things a step further by improving stream quality and wildlife habitat as well.
Norton Creek is classified as a fish habitat stream, but fish passage had been compromised by gradual sediment buildup. County engineers believe that at some point in the past 150 years the stream was rerouted as part of a large-scale project to drain surrounding wetlands for agricultural use.
Erosion wasn’t an issue because the stream banks are composed of fine silt and clay, but water flow during storms exceeded fish passage parameters. As a result, the county’s primary environmental objectives were to reduce velocities and create a natural channel.
Following a wetland delineation, county crews cleared brush on one corner of the bridge to straighten the roadway alignment and slow water flow by widening the creek. Originally 11 feet wide, the stream’s active channel now ranges from 13 feet to 15 feet.
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