Oregon's horizontal drain applications span the Coast Range's persistent marine rainfall exposure and the Columbia Gorge's seasonal snowmelt, giving ODOT two distinct groundwater sources requiring drainage design calibrated to whichever pattern a given corridor experiences.
It's a recurring example of the Steep Slope Stability Issues conditions ODOT and local owners manage statewide.
Horizontal drains for Oregon's Coast Range slopes are sized for persistent, near-continuous marine rainfall infiltration, distinct from the Gorge's more seasonal snowmelt pattern. This is one application of GSI's broader horizontal drains expertise.
Reducing pore water pressure through horizontal drains addresses Oregon's two distinct infiltration sources — coastal rainfall and Gorge snowmelt — with drainage calibrated to each. GSI's soil nailing experience informs this approach.
GSI pairs horizontal drains with soil nailing on Oregon slopes where either coastal rainfall or Gorge snowmelt saturation exceeds what drainage alone can manage. This draws directly on GSI's landslide emergency response work.
GSI's engineers experience also informs how these Oregon projects are scoped from the start.
Engineered for Oregon's conditions. GSI calibrates Oregon horizontal drain design to the state's two distinct groundwater sources — persistent Coast Range rainfall and seasonal Columbia Gorge snowmelt. Supported by general contractors and our case studies.
Design/build delivery. One integrated team owns the full scope — closing the gap between what's designed and what's built.
ODOT specification compliance. Design records and field practices satisfy state DOT specifications from initial design submittal.
GSI's engineers are ready to assess horizontal drains conditions at your Oregon site.
