The construction of hydroelectric plants directly affects the stability of the region's soil. One of the effects generated by this instability, the seismicity triggered by reservoirs, can directly affect the surrounding populations and the structure of the plant itself. To better understand the effects and causes of seismicity triggered by reservoirs, it is necessary to determine local properties such as resonance and amplification. Data from historical earthquakes and other secondary seismic sources, such as explosions, are commonly used to understand the subsurface soil's behavior. Another alternative is the HVSR method (horizontal-to-vertical spectral ratio), which uses the ratio between the horizontal and vertical spectra to eliminate the influence of the propagation path and determine the fundamental frequency of the ground, as well as the thickness of the sedimentary packages. In the present work, the HVSR method determines the fundamental frequency variation, natural resonance, and thickness of sedimentary packages associated with the Nova Ponte Dam in Minas Gerais. The results obtained were integrated with pre-existing geological and geophysical data, aiming to understand the causes of seismicity and its relationship with the subsurface structure of the region. Since the dam filling in October 1993, seismicity has been concentrated in two regions, both in the western portion of the reservoir. The two main earthquakes occurred in 1995 and 1998, with an intensity of 3.5 mR and 4.0 mR, respectively. To better understand the region's seismicity, seismometers were installed in 75 points with high seismicity and grouped into three different sectors. Window lengths between 15 and 60 seconds were used, depending on the local factors that cause noise, such as vegetation, passing vehicles, or wind intensity. Sampling used a frequency of 100 Hz. For data processing, the Python package hvsrpy is used. The fundamental frequency values ranged from 0.2Hz to 12Hz, with a possible relationship of the highest values with the limits between the sediments of the Marília Formation and the basaltic flows of the Serra Geral Formation.