Patent ID: 8465231

Claim:
A graduated silt fence comprising a woven geotextile fabric that includes a cross-plane permeability coefficient defining a permittivity which is increasing from one width edge and to the opposite width edge of the geotextile fabric, wherein the change in the permittivity is accomplished by a variation in weaving pattern, and wherein the variation in the permittivity throughout the geotextile width remains constant throughout the geotextile length, whereby when installed, the graduated silt fence provides a low permittivity for lower portions of the fence and as height increases, the geotextile fabric contains a greater permittivity created by change in material weave providing the greater permittivity within the textile structure allowing an increase in flow rate through the fence, wherein the variation in weaving pattern includes the use of a plain weave, adjacent a twill weave section, adiacent a satin weave section and further including a support geogrid formed of a mono-directional extruded material that is attached to the top of geotextile fabric and is of a greater material thickness and stiffness than the woven geotextile and is formed as a continuous strand of hollow rectangular structure along the top length of the woven geotextile, and wherein the geogrid is slotted to provide an overflow preferential pathway at the upper portion of the installed silt fence through the geogrid.