Hydrodynamic pressure becomes an important parameter exerted from the adjacent reservoir due to the earthquake effect on the dam surface. It generally depends upon the geometrical and material properties of the reservoir. This paper illustrates the seismic characteristics of an unbounded reservoir having an inclined dam-reservoir interface subjected to ground motion using the finite element method. The fluid domain is discretized with finite elements. A reservoir is curtailed at a certain distance from the dam structure. The non-reflecting boundary condition is applied over the truncated surface of the reservoir to convert the infinite domain into finite one. The dam structure is regarded as rigid while the reservoir is recognized as absorptive. Water in the reservoir is accounted as non-viscous and linearly compressible. The surface wave effect is neglected in the current study. Pressure is recommended as the unknown parameter for this analysis by introducing the Eulerian approach. The reservoir has an inclined dam-reservoir interface and the horizontal reservoir bottom is considered to evaluate hydrodynamic pressure. The pressure enhances with the increment in the inclination angle of the dam-reservoir interface. The maximum pressure was discovered at the dam heel for the vertical dam-reservoir interface and horizontal reservoir bottom. Hydrodynamic pressure coefficient variation is also observed for a reservoir having an inclined dam-reservoir interface with a sloped reservoir bottom. The inclined reservoir bottom generates more pressure than the horizontal reservoir bottom for a reservoir with an inclined dam-reservoir interface. A numerical program is implemented in the context of the study.