Record-low Rhine water levels (Kaub 24cm, lowest since 1880) disrupt inland-waterway freight for German steel/chemical clusters that cannot fully substitute to rail/road. Mechanism: a real-economy supply-chain drag on German industrial output — ING sizes ≥0.3pp off 2026 GDP with upside risk given out-of-sample levels — a growth-headwind partial counterweight to the eurozone-growth-resilience read. Bears on 6E (marginal EUR growth drag) and European industrial context; no direct primary-tier future.