'IRAQ AND THE PERSIAN GULF' [‎283v] (569/862)

438 IRRIGATION, AGRICULTURE, AND MINOR INDUSTRY
Other works are the regulators of the Bada and Shatra channels of
the Gharraf near Shatra, which restored winter irrigation on the tail
of the Gharraf before the Kut barrage was built. The Kut barrage
enables water to be supplied to the whole Gharraf regularly in winter,
which hitherto depended on the uncontrolled vagaries of the Tigris.
The area under cultivation has not yet greatly increased but has been
given a stable water-supply. In summer the Tigris supply is needed
for the Amara region and is not available for the Gharraf. The
maximum irrigable area is estimated at 750,000 acres (1943).
The Dujaila canal is the most recent project of the Irrigation
Department. When completed it should bring 230,000 acres under
cultivation, 150,000 by flow and 80,000 by lift irrigation. The first
section was expected to be ready for the winter season of 1944. No
other details are yet available.
(5) The canals and spillways from about Amara to Qala Salih: the
Mashara, Chahala, and Michariya on the left bank of the Tigris, the
Butaira and the Tabar and Mijar al Kabir on the right bank (p. 52;
fig. 10, opp. p. 39). All these except apparently the Mashara are
controlled by regulators.
Barrages and Weirs
The three great works on which the controlled system depends are
the Hindiya barrage, the Kut barrage, and the Diyala weir.
The Hindiya Barrage, which dams the Euphrates 6 miles below
Musaiyib, was originally built by Willcocks in 1908-1913 and was
reconstructed in 1921-1922 (photos. 161-164). It is 787 feetlongand
has 36 spans, each 16*5 feet wide, fitted with Stoney patent gates, and
there is a lock on the east side (26 ft. X 180 ft.). Its principal function
was originally to divert water down the Hilla channel which was
running dry (p. 35), but by its sluice gates and the regulators at the
heads of the Hilla and adjacent canals it now controls water down the
Euphrates and the four canals, besides assisting the left-bank canals
farther upstream by maintaining a higher level in the river. The
completion of the Habbaniya scheme—by the proposed Dhiban cut
(p. 29)—originally planned as a supplement to the barrage, would
enable a great quantity of water to be held in reserve in the Habbaniya
lake after the winter floods and released later in the summer season.
But it would first be necessary to clean the lake of an immense
quantity of saline deposits which have accumulated through cen
turies and render the water at present useless for irrigation. So far
the Habbaniya lake is simply used as a means of flood control.