Image Number 2 for United States Patent #6428240. A length of
material, such as woven polyethylene, woven polypropylene,
burlap, or other woven material, divided into a series of two or
more substantially equal sized sections. Every other section is
filled with sand, or other material. When the length of material
is put in place, each row alternating a filled section and an
unfilled section, a very secure, interlocking, substantially
water-tight structure is formed which is much more effective in
preventing the flow of water, mud or silt. Because each section
is substantially square, the sections can be stacked in a
parallel or transverse direction, to effect a wider and stronger
structure which is substantially impervious to the flow of
water, mud or silt.