Dam owners across Canada are required to make high-stakes decisions regarding the rehabilitation or replacement of aging, high-consequence spillways to rehabilitate the assets urgently due to safety issues. Evolving regulatory expectations, climate-driven hydrologic uncertainty etc. can be drivers. While structured decision-making tools and risk assessment processes provide important support, they represent only one element of a broader decision environment. This paper focuses on the complementary and often under-described role of the consulting Owner's Engineer (OE) in structuring, integrating, and de-risking complex infrastructure decisions. Using an embankment dam spillway replacement project as a case study, this paper describes how the OE supported the Owner beyond traditional design review activities. The 75 year old spillway, (a very high-consequence structure,) was experiencing increasing deterioration and growing uncertainty regarding its ability to safely pass the design flood. Multiple technically viable replacement concepts emerged during the planning and preliminary design phases, each presenting different risk profiles related to constructability, construction-phase flood exposure, environmental permitting, schedule constraints, and cost uncertainty. The OE's role centred on integrating technical inputs supplied by the Design Engineers and Contractors—including hydrology, geotechnical and seismic investigations, environmental considerations, dam safety assessments, and historical performance information—with project delivery considerations such as Early Contractor Involvement (ECI), independent cost evaluation, procurement strategy, and construction sequencing. Particular emphasis was placed on evaluating construction-phase dam safety risks and understanding how delivery approaches, schedule decisions, and temporary works requirements could influence both interim and residual project risk. The OE also supported broader Owner functions, including interim dam safety planning, regulatory engagement, governance discussions, and communication of project risks to senior decision-makers. The OE provided a structured framework that aligned engineering alternatives with the Owner's broader dam safety management objectives, capital planning priorities, procurement strategy, regulatory commitments, and organizational risk tolerance. Through collaborative workshops, independent evaluations, and ongoing stakeholder coordination, the OE facilitated a significant shift in project direction as new information emerged during Project development. This paper demonstrates how early and continuous OE engagement can improve results for the Owner through decision quality, stakeholder alignment, and risk management for high-consequence infrastructure upgrades, particularly in remote or climatically constrained environments. The presented framework is transferable from spillway replacement to dam safety remediation programs, and other aging water infrastructure projects where technical, operational, commercial, and governance considerations must be balanced to achieve successful outcomes.