A drainage element is constructed of loose fill elements within a casing having
a first part-circumferential portion of mesh construction and a second part-circumferential
portion having a porosity to prevent the passage of water. The loose fill elements
are disposed in unconnected relation to each other so as to be able to migrate
within the container. The openings of the mesh container allow water to pass through
while retaining the loose fill elements in place. In one embodiment, a porous layer
is secured to a bale shaped drainage element in order to form a sleeve to receive
a perforated pipe.