Vegetative filters (VF) are used to remove contaminants from agricultural runoff and improve surface water quality. State and federal cost-share funds are available to encourage landowners to install VF. The USDA-National Conservation Buffer Initiative calls for 3.2 million km of buffers to be installed by the year 2002. Numerous experimental plot and modeling studies have quantified the removal of sediments and other non-point source (NPS) contaminants from agricultural runoff by VF. Almost all of these studies have been conducted under controlled settings, including artificial sheet flow conditions, and using expensive, labor-intensive measurement systems. There is a critical need for simple, low-cost measurement systems that can be used to assess VF performance under realistic field conditions. A simple runoff measurement device would help to quantify and sample overland runoff and contaminant transport while accounting for spatially variable patterns of runoff from fields as they occur in nature.