Surficial slope failures are generally induced by the collection of precipitation in the cracks formed during dry summers. In the present research, an earthen dam in North Texas subjected to past failures due to surficial slope failures was selected. Soil from the site was sampled and studied for basic and advanced soil parameters including Soil Water Characteristic Curve (SWCC) in laboratory. Moisture probes were installed along the test section and monitored for a period of time. The variation of field moisture content reflected directly through the sensors placed at specific depths. The critical volumetric moisture content data obtained from the field instrumentation was correlated with SWCC to determine soil suction characteristics, which in turn was correlated to unsaturated soil strength parameters. These parameters are used in numerical modeling to assess slope stability issues. This paper presents these findings, along with the importance of soil suction, on rainfall induced slope failures.