Studies related to the tidal bore phenomenon in the Rokan Estuary are limited. Therefore, revealing the physical characteristics and the environmental impact of a tidal bore is crucial. This study aims to determine the tidal regime in the estuarine area, the propagation of the tidal bore, and the transport mechanism throughout the Rokan River. A tidal harmonic analysis and a hydrodynamic model based on Saint-Venant equations were performed. The amplitude of M2 and S2 (semidiurnal co-tidal constituents) showed a sufficiently high magnitude upstream (around 0.5–1.4 m) with a shorter and more intense flood propagation (flood dominant). The tidal range peaked on average 5 m with a 6–6.5-hour displacement time during the full moon phase and lowered in amplitude and period during the first (third) quarter of the moon phase. A sudden increase in water level and velocity observed represented a hydraulic jump off a tidal bore. Of particular concern, the tidal bore height in the estuary was approximately 3 m and lowered by approximately 1 meter every 15 km upstream. The turbulent velocities showed a sharp increase in magnitude at the end of the ebb tide peaking at +0.5 m/s and significantly declined to approach −0.5 m/s during the passage of bore observed in the estuary (station R1), showing the reversal changes in the flow direction and magnitude. These mechanisms were not applicable upstream due to the irregular bottom morphology of the river channel affecting the transverse and vertical turbulent velocity. Some bed erosion-induced turbulence may affect the higher suspended sediment concentration (SSC), advected by the “whelps” beneath the first wave crest, transported upstream.