Two contour weep berms systems were designed and implemented to evaluate their performance at mitigating water quantity problems from a horse muck composting operation. The field-scale study focused on the hydrologic response of a standard contour weep berm and a modified contour weep berm. The modified contour weep berm incorporated a woodchip trench upgradient of a typical standard contour weep design. Monitoring occurred from July 2011 through spring 2012. Eight storm events produced measureable runoff for the standard contour weep berm; however, only five storm events produced measurable runoff for the modified contour weep berm. The largest storm event occurred on November 27, 2012 with rainfall depth of 49.0 mm. This storm event generated a total runoff volume of 183.1 m3 and 188.5 m3 for the standard and modified contour weep berms, respectively. All runoff produced from the storm events during the monitoring period was completely detained and infiltrated. No runoff was released from the horse muck composting facility through the passive dewatering system to down-gradient vegetative filter strips during the monitoring period.