Buffer/Filter Strips
ØNarrow strips of dense vegetation (usually permanent grass) on contour
-Effective by inducing deposition (partial credit) and spreading runoff
-Most of deposition is in backwater above strip
ØBuffer strips
-Multiple strips
-Either at bottom or not a strip at bottom
-Water quality-must have strip at bottom and this strip twice as wide as others
ØFilter strip-single strip at bottom
These strips are usually dense, permanent grass strips.
Also, very narrow stiff grass “hedges” are also used.
Should be placed as close to contour as possible for maximum effectiveness.
Otherwise runoff can flow along upper edge.
Buffer strips are multiple strips on a slope.
Last strip may or may not be placed at bottom of slope.
If the last strip is at bottom of slope, it acts as a “filter” and significantly reduces sediment yield.
A single strip at the bottom of slope is a filter strip.
Most of deposition is in the backwater above strip rather than in strip.
Strip spreads runoff so that it leaves the strip with reduced erosivity.
Only partial credit taken for deposition for protecting soil resource.
Almost no credit taken for protecting soil resource by a filter strip.