Valencia Road


  • Drainage needed to be designed for roadway segment within broad shallow sheet flow area.
  • Modeling required a unique approach that reflected floodplain storage.
  • Cross-drainage design was needed for sheet flow conditions.


  • FLO-2D modeling for hydrology and hydraulics.
  • Model flow across roadway segments between proposed cross-drainage locations.
  • Size cross-drainage based on discharges between crossing points.


  • Both peak flow rates and flow depths were modeled.
  • Discharges along roadway segments between cross-drainage locations was modeled.
  • Rating curves for culverts were developed using HY-8 based on total discharge between culverts and next upstream crossing.

Project Highlight: Valencia Road – Mark Road to Ajo Highway


Pima County, AZ


HDR, Pima County Department of Transportation

Project Leads

John Wallace