The Ingenieur Vol 57 January-March 2014 The Ingenieur Vol 57 January-March 2014 | Page 79

View of the Bottle-neck channel
created by cutting through the
hill consisting of rock 2200
years ago by applying fire and
cold water technique

Southern Bridge for
pedestrian only

Beautifully decorated roofcovered South Bridge across the
inner stream

Inscription stone describing the
history and working of the levee
and the irrigation system built by
Li Bing

irrigation purposes and 40%
flows into the outer stream.
During the flooding season, only
40% of the water flows into the
inner stream to mitigate flooding
in the region. The swirling action
of the swift water flow helps to
flush out the silt and sediment
from the outer stream when the
inner stream joins it at the lower
level. The outer stream absolves
the rest of 60% of water diverted
from the levee.
2. Lower reach sand weir called
Flying Sand Weir - Feishayan.
This weir at the lower reach
has a 200 m wide opening that
links up the inner stream to the
outer streams. The function is to
prevent flooding by allowing the
swift swirling water of the inner
stream to channel out excess
water to the outer stream. By
this action, the swirl also flushes
out the silt and sediment to the
outer stream.
3. Bottle-Neck Channel –
Baopingkou
The narrow channel in the
mountain that Li Bing’s team
gouged out
was engineered
to create a swirling action that
enables the flow to carry excess
water to the Flying Sand Weir.
When the irrigation system
began its operation, Li Bing
created a maintenance and
operation manual as the bamboo
baskets filled with stones
require periodic maintenance.
However, over time, some of the
structures were strengthened by

other means.
UNESCO Heritage Status
Dujiangyan irrigation system is
now a living heritage of a 2,200
years old design and engineering
idea that still serves the region’s
agriculture
production.
The
structure was placed on the
World Heritage List in 2000. It
has also been declared a State
Priority Protected Site which
is among the National Scenic
Areas and Historical Sites.
During the Sichuan earthquake
on 12th May, 2008 during which
Dujiangyan town was affected,
the Dujiangyan irrigation system
was undamaged.
In honour of Li Bing and his
son’s contribution, a temple with
his statue was built next to the
inner stream river bank.
Tourist Features
A beautiful ancient roof-cover
South Bridge was built across
the inner stream with art works
and carvings lining the side wall
that offers a good view of the
swift flowing inner stream.
Samples
of
basket
filled with stones used for
the construction and wooden
tripod of original levee are also
displayed along the way to the
Fish-Head levee.
It was a worthwhile trip
to reflect upon the marvel of
irrigation works of such a scale
built 2,200 years ago that still
serves its original function and
has stood the test of time and
earthquakes.

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