The region of Laguna is strongly faulted given the presence of the Marikina Valley Fault which traverses a north-south direction. The fault is disrupted by a number of minor steep faults along its course that is reflective of the volcanic activity relative to the area. Earthquakes are a hazard in Santa Rosa as the West Marikina Valley Fault traverses Sto. Domingo.
Floodplains of the municipality sprawl a total area of 302 ha. Situated in this zone are Sinalhan, Aplaya and Caingin, and in portions of Tagapo, Ibaba, Labas, Pooc, Dila and Dita.
Slight seasonal run-off flooding is characterized by accumulated shallow run-off flood, which subsides within a short period ranging from a few hours to three days. This occurs in low to moderately low flood plains situated in Kanluran, Malusak and Ibaba. Floods in these areas are due to run off accumulation coming from surrounding elevated areas, their low physiographic positions, poor infiltration, permeability characteristics and drain ability outlet. These areas are perceived as poor for urban uses. Flood limitation could be minimized by proper and adequate drainage planning for draining unnecessary water.
Moderate seasonal flooding is characterised by more frequent and deeper run-off water. Subsistence of floodwater takes a week to a few months. This condition is observed along the lakeshore in Caingin, Aplaya and Sinalhan and in the adjacent northeastern tip of Ibaba, Market Area and Tagapo. These areas serve as the catchment of water coming from the higher areas and are characterised by poor drain ability outlets, very low infiltration and hydraulic conductivity.