The topography of Alaminos is characterized by a flat plain. The plain elevation is less than 20 meters above sea level and is surrounded by 100-200 meter-high limestone hills. The rounded hills in the east are mostly covered with wild vegetation stretching northward towards the sea to form part of the Hundred Islands. The Alaminos River and some minor main streams fertilizes the plains which grow a variety of agricultural crops. (Slope Map)

In terms of area distribution, 16% of the 16,000 hectares are within less than 3 percent  slope or lands that have flat or level terrain. About 5,718 hectares or 35.66  percent are within a slope range between 8-18%  slope and about 1,100 hectares have an slope of greater than 50%.