Date of Award


Document Type



Environmental Engineering

First Advisor

Annette Dietz


Seepage -- Mathematical models, Urban Runoff -- Mathematical models, Soil conservation -- Oregon -- Portland




It is useful to estimate infiltration rates and potentials for several reasons. Information about infiltration at a site may be to evaluate surface irrigation systems, to predict hydrologic conditions, and to solve many other problems (Ojha, et al., 2017). This thesis project is based on my engineering capstone project, which is to design a solution to control erosion in the soil bed adjacent to Henry V Events. There is erosion in the soil bed due to stormwater runoff from the roof, and due to the sloped soil bed which encourages the overland flow. The objective of this thesis is to estimate the infiltration rates and potentials at the site for a six year, four hour storm event using the Green-Ampt and Philip models. This will determine if only the soil bed slope can be changed to prevent erosion, or if soil bed improvements should ensue. The most conservative estimate was calculated using the Philip model and resulted in an infiltration rate of 0.77 cm/hr and an infiltration potential of 4.27 cm. This estimate determined that the soil would not be able to infiltrate the flow from the roof, and soil bed improvements will be recommended to Henry V Events. The soil suction head from the Green-Ampt model was estimated, as well as the length of the wetting front from the Philip model. A second analysis was performed using the infiltration models by varying the soil suction head and wetting front length for their respective models. The results showed how different soil suction heads and wetting front lengths change the infiltration rates and potentials for the four hour storm. There was a greater variability in the infiltration rates and potentials for both models with samples that had lower initial moisture contents.


An undergraduate honors thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in University Honors and Environmental Engineering.

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