"كتيّب بلاد الرافدين. المجلد II. ١٩١٧" [‎٤‎٥‎٥] (٥٤٢/٤٦٦)

CONTKOL OF TIGRIS WATER
455
down -stream. The weir at the Michrlyeh head, if completed, may help
to improve navigation below Qalat Salih, Sir William Willcocks
in 1905 recommended training the river by willow mattresses and by
massive blocks of fused brick.
Between Ezra's Tomb and Kurna much of the water that had
escaped from the Tigris above comes back into the river, which
therefore broadens and deepens as Kurna is approached. Some of
the Tigris water from the right bank also passes into the Hammar
Lake or the Old Channel of the Euphrates, and rejoins the main
stream (the Shatt el-'Arab) by one or other of the Euphrates mouths
(either at Kurna or at Gurmat All).
It may be observed that some of the conservancy measures
mentioned above would temporarily affect the habits of the natives,
who might make a grievance of this.
N ote on S ir W. W illcocks' S cheme foe the C ontrol op the
T igris W ater
(1) For the fully developed control of the Tigris water the funda
mental necessity is a system of works, including a barrage and an
escape, at the head of the Tigris Delta between Samarra and Beled.
The reasons for this are:—
(i) In this neighbourhood the country begins to drop below the
high flood level of the Tigris. At no lower point, therefore, would
it be possible to insure against inundation by the Tigris floods. For
such an insurance to be complete both a barrage and an escape are
of course necessary.
(ii) A diversion of Tigris water at this point would enable large
quantities of the flood supply of the river to be stored either in the
Tartar depression (SW. of Samarra), or in the depressions of Hab-
baniyeh and Abu Dibs (SE. of Eamadiyeh), on the farther side of
the Euphrates. Storage both of Euphrates and of Tigris flood-water
on a great scale is absolutely essential to the development of the
country, for Mesopotamian agriculture depends on perennial irriga
tion (owing to the season at which the floods occur), and the low
supply of the rivers is not nearly sufficient to support extensive
cultivation both in the districts up-stream of Kut and Diwaniyeh,
and farther south (the Shatt el-Arab country, &c.). Another
argument for such storage might be the extensive irrigation of Upper
Mesopotamia, which, according to SirW. Willcocks, could conceivably
deprive Irak of all the low supply of the Euphrates and a great part
of the low supply of the Tigris, If Upper Mesopotamia were heavily
irrigated by another Power, it would be necessary not only to store