Floodplain Mitigation Study and Scour Analysis - Blue Ocean Civil Consulting
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Floodplain Mitigation Study and Scour Analysis

Government, Consultant
Halawa, Oahu, Hawaii

Our Approach

Blue Ocean provided hydraulic engineering support for the Airport Guideway and Stations (AGS) segment of the Honolulu Rail Transit Project (HRTP) to study the impacts of the guideway crossing over Halawa Stream.


Stream stability and scour potential at pier locations were both quantitatively and qualitatively investigated. The analysis was based on an updated one-dimensional model, while a two-dimensional model, as well as review of historic aerials and topography, was completed to verify the complex hydraulic conditions both through the bridge crossing sections and more generally throughout the lower portion of Halawa Stream.


Blue Ocean also provided an evaluation of the Flood Hazard impacts of the project within the Federal Emergency Management Agency (FEMA) and Revised Ordinances of Honolulu (ROH) regulatory framework. Using the hydraulic models developed as part of the scour analysis, the impacts to the stream velocities and depths were quantified for the temporary trestle and permanent guideway pier structure conditions.