Introduction: Soil hydrophobicity is the inability of a soil to readily wet or allow water to infiltrate into dry soil (Figure 1, Doerr et al., 2010). Understanding soil hydrophobicity is important to soil scientists and land managers because it directly affects runoff and erosion. The main cause of soil hydrophobicity is burning. Hydrophobicity of soils after fire results in decreased infiltration rates, leading to an observed increase in runoff and erosion after fire (Doerr et al., 2010). This study will focus on the effects of fire-induced hydrophobicity on infiltration and runoff. Figure 1: Water droplets that resist infiltration in highly porous hydrophobic soil (Doerr, 2007). A better understanding of the causes of soil hydrophobicity is warranted. understand its effects on infiltration and runoff. Fire is not the only factor that can make the floor water-repellent. Soils may be slightly hydrophobic at low to moderate moisture contents, under burned or unburned conditions (Doerr et al., 2010). Different combinations of vegetation and soil type can develop strong soil hydrophobicity. Soils under certain vegetation types with oil- or wax-rich leaves (i.e. shrubs, conifers, and eucalyptus) are more likely to become hydrophobic than soils under broad-leaved vegetation ( Doerr et al., 2010). Soil particle size also plays a role in susceptibility to the development of water-repellent properties. Coarser soils are more likely to become water repellent than finer soils due to their smaller surface area and fewer potential adsorption sites for organic molecules (DeBano, 1981). How does fire cause soil hydrophobicity? Burning induces a water-repellent nature of the soil by volatilizing the hydrophobic organic compounds present in the litter and the topsoil (Doerr et al., 2010). This results in the development of a pressure gradient within the leaf litter or topsoil that causes some compounds to be released into the atmosphere while others are forced into the soil (Doerr et al., 2010 ). As the gas seeps into the soil, it cools at depth, causing it to condense on soil particles at or below the surface of the soil. This phenomenon creates a waxy layer around the grain of the soil, causing it to repel water. Laboratory studies show that soil water repulsion is intensified at soil temperatures of 175 to 270 °C, but is destroyed at temperatures above 270 to 400 °C (Doerr et al., 2010). Once a soil becomes hydrophobic, it does not always stay that way. in this way; in fact, most soils become less hydrophobic or lose their hydrophobicity over time. Burned and unburned soils become less hydrophobic or lose hydrophobicity completely as soil moisture increases..