Washington State Department of Transportation

SL9727-XXX

{{DATE}}

Dan Galvin, Chair
Dispute Review Board
I-405, Brickyard to SR 527 Improvement Project

Via Email: [email protected]

Reference: Contract No. 9727
I-405, Brickyard to SR 527 Improvement Project

Subject: Dispute Referral – Protest 003: Lateral Migration / Sammamish River (PCO 126)

Dear Mr. Galvin:

In accordance with RFP Section 1-04.5(1) and the Three-Party Agreement dated November 28, 2023, the Washington State Department of Transportation (“WSDOT”) hereby refers the dispute arising from Protest 003, Lateral Migration / Sammamish River, to the Dispute Review Board (“Board”) for hearing and recommendation.

This dispute concerns whether the Contract requires the Design-Builder to apply a “not low” lateral migration determination to new structures crossing the Sammamish River, as specified in Section 2.30.5.2.1 Certain Structure and Channel Design Characteristics. The Design-Builder’s hydraulic designer (AECOM) applied a “low” classification in the draft Final Hydraulic Design. WSDOT issued an Interpretive Engineering Decision directing compliance with the contractual “not low” requirement. The parties have been unable to resolve the resulting dispute through the protest process.

WSDOT is confident that the Contract provisions are clear and unambiguous and welcomes the Board’s review.

1. Procedural Background

2. Nature and Specifics of the Dispute

a) Background

Section 2.30.5.2.1 Certain Structure and Channel Design Characteristics provides:

“The Sammamish River ‘not low’ lateral migration determination discussed in the Sammamish River Migration Risk Assessment (Appendix H) shall apply to the new structures within the river flow limits defined by the 500-year flood elevation.”

This provision was added via Addendum 14 (March 2, 2023). Appendix H26 was added via Addendum 9 (January 19, 2023). The Contract was awarded in July 2023, giving the Design-Builder approximately six months’ notice.

b) Three Affected Structures

1. NB I-405 to EB SR 522 Ramp Bridge – constructed. Foundations in place.
2. NB I-405 Mainline Bridge – in construction.
3. DAR Bridge – in design phase. Construction scheduled April 2026.

c) AECOM’s Role

AECOM serves as the Design-Builder’s hydraulic designer. AECOM prepared the draft Final Hydraulic Design applying a “low” classification based on independent analysis (HEC-20, BSTEM, FHWA Rapid Assessment). AECOM also authored the AECOM Notice of Dispute (February 11, 2026) introducing the Section 1-03.1 argument regarding H26’s document classification.

d) Key Divergence Points

WSDOT’s position: Section 2.30.5.2.1 establishes the “not low” determination as a mandatory contract requirement. The provision references the determination “discussed in” H26 — a citation to a completed assessment — and states it “shall apply.” Engineering analysis cannot override explicit contract language. The IED correctly interprets existing requirements per Section 1-03.5.

Design-Builder’s position: The “not low” determination should serve as a trigger for further analysis, not a predetermined outcome. AECOM’s engineering analysis demonstrates the actual risk is “low.”

Cost estimates provided: Option 1 (Sheet Pile) at $7,809,741. Option 2 (Rock/Log Vanes) at $450,032. Both exclude CLOMR costs, extended general conditions, permitting, and potential reconstruction.

3. Key Contract Provisions

Technical Requirements (RFP Chapter 2)

• TR 2.30.5.2.1 Certain Structure and Channel Design Characteristics (“shall apply”)
• TR 2.30.5.1 Flood Risk Analysis (zero rise or CLOMR)
• TR 2.14.6.6 Zero Rise Standard
• TR 2.30.5.6 Scour Analysis

General Provisions (RFP Chapter 1)

• GP 1-03.1 Contract and Reference Documents
• GP 1-03.5 Ambiguities / Interpretive Engineering Decisions
• GP 1-04.4(2) Design-Builder Initiated Changes
• GP 1-04.5 Protest and Dispute Procedures

Appendices

• Appendix H26 Sammamish River Migration Risk Assessment
• Appendix D01 BDM Section 7.1.7 Scour Requirements
• Appendix B04_2 Design Memorandum
• Appendix D08 Hydraulics Manual

4. Scope of Recommendation Requested

WSDOT respectfully requests the Board’s recommendation on the following question:

Does Section 2.30.5.2.1 Certain Structure and Channel Design Characteristics require the Design-Builder to apply the “not low” lateral migration determination to Sammamish River structures, or does it permit the Design-Builder to reach a different determination through independent analysis?

The Board’s recommendation on this question will necessarily address the subsidiary issues of IED validity under Section 1-03.5, the proper mechanism for changing contractual design requirements, and entitlement to cost or time adjustment.

5. Next Steps

WSDOT respectfully requests that the Board Chair confer with the parties to establish:

1. A briefing schedule for pre-hearing submittals (Position Papers) and rebuttals
2. Deadlines for Notice of Experts (30 calendar days prior to Position Paper due date per Section 1-04.5(1).1.8)
3. A date, time, and location for the hearing

Per Section 1-04.5(1).1.8, WSDOT will arrange for hearing facilities at or near the project site.

WSDOT is prepared to proceed promptly with hearing preparation.

If you have any questions, please contact me at (425) 495-1577.

Sincerely,

Evelyn Pao, P.E.
Project Director
Washington State Department of Transportation
18911 N Creek Pkwy S, Suite 150
Bothell, WA 98011

cc: Don Irwin, DRB Member; Michael Morishige, DRB Member; Patrick Prendergast, Skanska USA Civil; L. Hodgson, R. Woeck, D. Case, D. Holmquist, J. Slavicek, S. Berriz, B. Kane, N. Bergeman, R. Gehrlein, E-File