Problems
Holes or gaps have to be left in the pipes to allow water to transfer from the subsoil to the pipe and these tend to block with soil or allow silt into the pipe, so blocking it or reducing the flow of water. This can be partially overcome by surrounding the pipes with gravel. However, with time even the gravel becomes choked with soil/silt, so in the latest practice, the gravel is surrounded with a geotextile material which filters out soil particles. Ideally, land drains are laid with access points so that high pressure water jetting is possible to clear silt. However, whatever the technology, all land drains have a finite life and eventually become ineffective due to the ingress of silt and/or the blocking of the surrounding filter media.
Read more about this topic: Land Drains
Famous quotes containing the word problems:
“The problems of this world are only truly solved in two ways: by extinction or duplication.”
—Susan Sontag (b. 1933)
“We are all adult learners. Most of us have learned a good deal more out of school than in it. We have learned from our families, our work, our friends. We have learned from problems resolved and tasks achieved but also from mistakes confronted and illusions unmasked. . . . Some of what we have learned is trivial: some has changed our lives forever.”
—Laurent A. Daloz (20th century)
“The man who is forever disturbed about the condition of humanity either has no problems of his own or has refused to face them.”
—Henry Miller (1891–1980)