 |
 |
|
 |
 |
“Persian Works”
Beginning around 2000 BC Iranian people were building
tens of thousands of miles of irrigation tunnels or early
“collector” type wells.
Collector wells may be of one of two types. The first is a
single or series of near horizontal wells entering the
aquifer at one end and gently sloping downward at an
angle less than the surface gradient. The tunnel exits the
ground at a lower elevation where the water is used for
irrigation purposes.
A series of vertical shafts are extended upward to the
surface along the tunnels’ journey. These vertical shafts
serve several purposes. They provided ventilation in the
tunnel during excavation; they provided a more efficient
means for the removal of construction debris, and these
vertical exit points became a series of vertical wells that
can tap into the horizontal tunnel below providing a
source of water at intervals over the entire length of the
tunnels’ journey from aquifer to exit point.
HISTORY
OF
WELL
CONSTRUCTION
AND
RELATED
MATTERS
|
 |
|