The ideal placement for a silt fence is along the contours of a slope, perpendicular to the flow of water. It should be positioned below disturbed areas where sheet erosion or rill erosion is likely to occur. It is important to install the barrier on flat ground just beyond the toe of a slope to allow water to pond effectively. The ends of the barrier should be flared upslope in a crescent shape to prevent water from flowing around the edges. It should never be placed across concentrated flow paths like ditches, streams, or channels.
Read More – https://www.singhalglobal.com/products/silt-fence