A barrier is disclosed which includes a connected pair of upstanding and equidistantly spaced first and second walls which together define a channel having a bottom and an open top. Dirt or rock fill (or fill of any other non-vegetative material) is poured into or otherwise placed in the channel between the walls to cover the bottom of the channel and at least partially fill the channel. The area of the channel containing the fill may be lined with geo-textile material to help contain the fill.