Three categories of land formations constitute the area of Santa Rosa. These are the lacustrine alluvial plains, broad alluvial plains, and the undulating tuffaceous plains. Each classification is briefly described below.
a. Lacustrine alluvial plains occur along the lakeshore areas. Fluctuations of lake waters along this edge of the municipality have dictated its land formation and vegetative cover. Situated along the lakeshore are Sinalhan, Aplaya and Caingin. Portions of the Market Area and Ibaba are considered lacustrine as well.
b. Broad plains consist of higher and more stable flood plains on level to nearly level terrain formed by alluviation. The soils are moderately well drained. A majority of the barangays, including the Poblacion, may be found here. These include Tagapo, Kanluran, Malusak, Labas, Dila, Dita, Pooc and portions of the Market Area, Ibaba, Pulong Sta. Cruz, Malitlit and the lakeside barangays
c. Undulating tuffaceous plains are moderately dissected piedmont plains with the topography of undulating to rolling. Steep side slopes may be found along dissections and rivers. Such a formation is found in Don Jose and Sto. Domingo along with portions of Pulong Sta. Cruz and Malitlit.