Surface water is categorized as a water source that is located over the ground or in other bodies such as the ocean, estuaries, ponds, reservoirs, wetlands, streams, creeks, lakes, and rivers. Although the ocean is largely consisting of salinity, it is considered surface water as well. The relationship between surface water and ground water works through the seepage of surface water into the underground and becoming groundwater, and groundwater resurfacing on land to refill surface water.