Electrical resistivity is a common near surface geophysical tool often used for site investigations; however, its use in civil infrastructure has yet to be fully realized. Collected field measuremnets must be proscessed through an inversion software and the positions of the electrodes must also be known to achieve a proper result. Provided in this dataset are the collected measurements for a site in San Marcos, TX where marine electrical resistivity tomography surveys were used to determine the depth and volume of an infilled scour hole for a bridge crossing the San Marcos River.