'Handbook of Mesopotamia. Vol. I. 1918' [‎26] (35/568)

26
BOUNDAEIES AND PHYSICAL FEATURES
to year, according to the volume of the flood, the way in which it
rises, and the obstacles or opportunities which it encounters. Condi
tions are constantly changing, and until the Euphrates and Tigris
are properly controlled they may always be expected to present
new problems.
The Euphrates between Eellujeh and Diwaniyeh flows at a higher
level than the Tigris between Baghdad and Kut el-Amara, and the
country between the rivers in north-western Irak is therefore flooded
mainly from the Euphrates. The flood-water finds its way through
long canals, the relics of the old irrigation-system, far into the
interior of the plain, and there forms shallow marshes. Just below
Museyib (70 miles by river below Eellujeh) the Euphrates bifurcates
into two large branches, called the Hindiyeh and the Hilla, which
join again 110 miles to the south-south-east near Samaweh. In the
past the main volume of water has flowed now in one, now in
another of these branches. Between 1865 and 1890 the main stream
shifted from the eastern (Hilla) branch to the western (Hindiyeh).
After several unsuccessful attempts to check the process, which was
thi'eatening to dry up the Hilla branch altogether, the new Hindiyeh
Barrage and the Hilla Regulator were constructed (1913) to regulate
the flow of water down the two channels. On the Hindiyeh branch
the Euphrates spreads out in large reedy marshes and broads, where
the Euphrates deposits much of its sediment. Below the junction
-of the two branches at Samaweh the Euphrates again flows in a
single channel past Nasirlyeh to the neighbourhood of Suq esh-
Shuyukh. From here part of the Euphrates water flows eastwards
to Kurna, where the Tigris is met. But from Nasirlyeh downwards
the Euphrates, now flowing at a lower level than the Tigris, receives
from the north a great quantity of Tigris water, which finds its way
through the canals and marshes between the two rivers. The volume
of the Euphrates, thus increased, is beyond the capacity of the
channel leading to Kurna (called the Old Channel), and most of the
Euphrates water is forced southwards and south-eastwards, and
lor ins a large area of open water and swamp, through which the
New Channel drains into the Shatt el-'Arab at Gurmat 'All, a few
miles above Basra.
The Tigris is liable to flood more or less of the neighbourhood of
its banks from above Baghdad down to Kut el-Amara. At the
latter place a large channel, the Shatt el-Hai, branches southwards
from the right bank of the Tigris, and in the months of high river
carries off a considerable quantity of water, which eventually reaches
the Euphrates below Nasirlyeh by various outlets. The Shatt el-Hai
was the main bed of the Tigris from the seventh to the sixteenth