Awareness of the possible contamination of our rivers and lakes with heavy metals resulting from urban runoff is necessary. The need for baseline data on pollution studies resulting from urban runoff to water bodies (streams, lakes, rivers etc) is of profound importance. This study focuses on the urbanized part of the Gallinas watershed of Las Vegas, San Miguel County, New Mexico - USA, which covers approximately 52,500 acres to the west of Las Vegas and is developed primarily with residential and light commercial areas. Significant amounts of urban runoff enter the Gallinas River from different drainages and areas during wet weather flow without pre-treatment. The primary objective of this study was to identify the various heavy metals and their concentrations associated with aqueous and suspended solid phases during wet weather flow before discharge into the Gallinas River.