A filter strip is a strip of gently sloping grass or other stable vegetation strategically planted between streams, rivers, ponds, lakes, storm, drains and sinkholes. These strips are designed as a barrier to remove sediment, organic materials, nutrients, pesticides, and other pollutants carried in agricultural runoff water. The filter strip works by slowing water flow and allowing the pollutant or sediment to settle before it gets to the water. Larger sediment particles of sand and silt are removed first, while smaller particles such as clay take longer to settle and can still get through.
BMPs can be built into the farming strategy used as preventative measures. Some examples consist of identifying surface water or potential soil erosion locations prior to starting any farming activities. Other BMPs can be physically built into the land such as filter strips, runoff diversions, or silt fences. These preventative measures are set in place to avoid costly clean-ups and eroded soil.