'Handbook of Mesopotamia. Vol. I. 1918' [‎154] (163/568)

154
IRRIGATION OF IRAK
the shallow valley which runs parallel with and west of the Shatt
el-Hai from near Kut towards Nasirlyeh. This depression affords
facilities for drainage.
(c) The Tigris from Kut to Kurna is higher than the Euphrates
from the neighbourhood of Nasirlyeh downwards, and commands
the country between the two rivers. (Ground-levels on the Tigris:
at Kut, 79 ft. ; at Kurna, 13 ft. Ground-levels on the Euphrates: at
N^sirlyeh, about 10 ft. ; at Basra, about 8 ft.)
(c?) The country on the left bank of the Tigris from the neigh
bourhood of Sindiyeh (about 40 miles in a direct line north of
Baghdad) down to Kut is commanded by the Diyaleh, and in part
by the Tigris.
The difficulties of introducing a scientific system of irrigation into
Irak are very great. How to secure control of the rivers and put theii
waters to profitable use is an extraordinarily complicated problem.
The beds of the Tigris and the Euphrates have been spoiled by
centuries of neglect and misdirected work on the part of the in
habitants. Water has been diverted for irrigation by reckless canal-
cutting, which has made it impossible for the rivers to keep their
beds properly scoured. Their channels have been damaged besides
by the encroachments of cultivators who have reclaimed land along
their banks. The result has been that the rivers have become quite
incapable of holding their flood-supplies. The flood-water has spilt
through breaches in the banks, or through canals ; some of which
have been widened and scoured till they have become nearly as
large as, or larger than, the original main stream. The great marshes
which are formed in the interior by inundation from the riveis aie
partly temporary and recurring, and partly, owing to lack of drainage,
permanent. One evil has led to another, and the process of the
degeneration and disintegration of the rivers has become more and
more difficult to check. A local improvement may easily cause
disaster elsewhere ; for example, to stop a spill in one place may
cause the river to break out in another.
Again, the supply of water available is not nearly large enough to
satisfy all the demands that might be made on it. This is obvious
under present conditions, when so much of the supply runs to waste,
when the Arabs have still the most inadequate notions of economy
in its use, and when primitive agricultural methods may make the
most lavish application of river-water drawn through unregulated
canals appear a necessity of cultivation, as, for instance, to the
ploughless rice-growing tribes in southern Irak. At present to
increase the supply of water for the irrigation of one district may