DC Water DC Water Blue Plains Floodwall Segment C

The Kokosing Industrial Design-Build team installed Segment C of the floodwall, which is comprised of a 660 linear-foot steel sheet pile wall. For aesthetic purposes the AWTP-side of the wall received precast concrete facing.
Floodwall construction included three significant discontinuities, which not only required extensive coordination with regulatory agencies, but significant geotechnical and structural design considerations.

• The floodwall traverses a major roadway on AWTP property, requiring construction of a removable aluminum floodgate system to be activated in advance of impending flood event(s).
• A second discontinuity at the crossing of a buried twin 230 kV electric transmission line, was spanned via a concrete wall extending below the transmission line and extending above grade.
• As the floodwall crossed the AWTP 48-foot wide and ten-foot tall twin cell concrete culvert primary outfall, W-section steel king piles were imbedded on each side of the outfall, with steel walers spanning said crossing.

To safeguard the Blue Plains Advanced Wastewater Treatment Plant (AWTP) – the largest wastewater treatment facility in the world – against 500-year flooding from the adjacent Potomac River, DC Water undertook a series of floodwall construction projects. Kokosing Industrial’s Design-Build team developed and released early procurement packages, finalized design documents and finished construction of Segment C of floodwall within 24 months. Completion of the project within the accelerated timeline allowed DC Water to be reimbursed for project costs via a FEMA grant.