P019 Internal Memo — Juanita Creek Lateral Migration IED

Date: March 11, 2026
Subject: Protest 019 (LTR 372) — Juanita Creek Lateral Migration — Internal Analysis and DRB Preparation
Responding to: Skanska LTR 372 (March 10, 2026) protesting WSDOT SL 9727-280 (February 24, 2026)
Purpose: This internal memo documents WSDOT’s analysis of Protest 019 for internal use and DRB preparation. Contains internal reasoning, argument rebuttals, and strategic analysis not for external distribution.

I. Contract Framework

A. Table 2.30-B and Section 2.30.5.2.1

Table 2.30-B designates Juanita Creek (I-405 MP 21.94) lateral migration (structural) as “low.” This designation has not been overridden. Section 2.30.5.2.1 establishes that Table 2.30-B designations “shall apply” and takes precedence.

B. BDM 8.1.10: Scour of Retaining Walls (Separate Mandatory Standard)

BDM Section 8.1.10 states: “Total Scour includes the amount of streambed vertical elevation drop at a given location due to the removal of streambed material caused by flowing water and the effects of lateral migration.”

This is a Mandatory Standard per RFP Section 2.13.4. It applies to ALL retaining walls near water, regardless of the Table 2.30-B fish passage classification. BDM 8.1.10 compliance is the Design-Builder’s responsibility. Figure selection (8.1.10-1, -2, -3) is driven by site-specific scour analysis, not Table 2.30-B.

C. Section 1-02.1: WSDOT Comment Shield

“Notwithstanding anything in the Contract Documents to the contrary, no field explanations or interpretations provided by WSDOT at any meetings, and no comments by WSDOT on Design Documents or Released for Construction (RFC) Documents, shall be deemed, construed, or interpreted to (a) amend, supersede, or alter the terms, requirements, limitations, or meaning of any Contract Document or (b) release or relieve the Design-Builder from full responsibility for the design of the Project in accordance with the Contract Documents. (However, Written Interpretive Engineering Decisions from WSDOT pursuant to Section 1-03.5 may be relied upon to provide information, clarifications and interpretations of ambiguous or uncertain design requirements set forth in the Contract Documents.)”

The shield is absolute for comments. “No comments” means all comments. No tone exception. No distinction between “suggestive” and “directive” comments. RCSR comments on the FHD are exactly “comments by WSDOT on Design Documents.” Section 1-02.1 applies directly.

D. Section 1-03.5: IED Authority, Entitlement Bar, Burden-Shifting

Key operative phrases: “WSDOT… may issue its own Interpretive Engineering Decision” (no DB request required). “No Interpretive Engineering Decision by WSDOT shall form the basis for an increase in the Contract Price or extension of the Contract Time, unless WSDOT expressly provides otherwise in writing.” “The Design-Builder shall bear the burden of proving that WSDOT’s interpretation is incorrect or unreasonable.”

II. RCSR Comment Analysis

225-Comment Language Pattern

Full analysis of Package 8 (202 comments) and Package 9 (23 comments) = 225 total RCSR comments:

• Zero comments using directive language (“WSDOT directs,” “you shall,” “the Design-Builder is required to”)
• Zero comments referencing Table 2.30-B lateral migration classification
• 54 “Please…” requests; 52 questions (“?”); 28 “Consider/Suggest/Recommend” instances
• All “shall” instances quote existing BDM/code standards — not WSDOT commanding the DB

Comment 2 (HQH, Package 9) is labeled “Preference” and suggests angled wingwalls (25–45 degrees). WSDOT actually suggested a design that would have AVOIDED the lateral migration scour concern. The Design-Builder chose the parallel orientation that created the problem.

Comments 3 and 4 (HQH, Package 9) — BDM Context

Both comments explicitly cite BDM 8.1.10, not Table 2.30-B. Comment 4 cites Figure 8.1.10-2 (Scour WITH Lateral Migration) because AECOM’s own analysis found conditions (erodible soils, beaver activity, insufficient data to exclude lateral migration) that pointed to that figure. The obligation to evaluate total scour for retaining walls is mandatory per BDM 8.1.10. The specific figure selection follows from the site-specific scour analysis, not from a blanket requirement.

III. Scour Depth Reality Check

The calculated total scour (0.65–1.16 ft) is far below the 3 ft WSDOT minimum. The minimum governs per WSDOT Hydraulics Manual. The cost driver is NOT deeper scour — the cost driver is the horizontal application of scour to the wingwalls (BDM 8.1.10 Figure 8.1.10-2 treatment), which requires the soldier pile walls to resist lateral erosion. Wingwall retained heights (31–42 ft) are driven primarily by the tunnel excavation depth, not scour.

IV. Cost Attribution ($5,466,392)

V. Defense Layering (DRB Strategy)

VI. WSDOT Strengths and Weaknesses

VII. P003 Coordination

Alignment rules — do NOT violate:

• Do not argue Table 2.30-B is “merely informational.” WSDOT relied on it in P003.
• Do not argue engineering analysis can override contract designations. That is Skanska’s P003 argument.
• Consistent position: Table 2.30-B designations stand as written. WSDOT enforces them. RCSR review is separate from contract enforcement.
• Do NOT make blanket statements that RCSR comments can never constitute a WSDOT position. Characterize each comment on its own terms.

VIII. Key Items Reserved for DRB Only

IX. Key Contract References

INTERNAL MEMO — Protest 019 — SKA-0303 — Prepared March 11, 2026