"ملاحظات ميدانية: بلاد الرافدين. هيئة الأركان العامة في الهند. فبراير ١٩١٧". [و‎‎٥‎٣] (٣٥٠/١١٢)

Tigris Navigation.
Above Baghdad navigation of the Tigris is usually only by
rafts, though small steamers can go up to Samarra; below
Baghdad steamers and sailing vessels are used. Of late years
the navigation has been getting increasingly difficult owing
to neglect of dredging operations, the want of supervision
over the local Arabs, who cut channels and primitive canals in
various unscientific ways, thereby causing the river to silt up or
open into broad shallows at embarrassing places, and to the
insufficiency of steamer traffic which would help largely to keep
open the existing channels.
Between Kut-al-Amarah and Baghdad all steamers stick
frequently at times when the river is low and have to be hauled
laboriously through shallow and winding channels, by means
of anchors and winches.
About the middle of November, sooner or later, according to
the season, rain causes the first rise in the river, and navigation
improves.
In January, February and March, rain keeps the river fairly
full, although the frost in the mountains may lower it.
In March, the snows up country begin to melt and the river
to rise, as much as 3 feet being recorded on one occasion in a
single night at Baghdad.
In April and May the river is at its highest.
In July and August it falls gradually, because the melting of
the snows on the higher ranges keeps up a fairly constant supply
of water.
In August, September and October, the river is at its lowest
but, in the last two months navigation is easier owing to the
channels having become formed and known.
The current in the low season is slight, and in flood the
■swiftest is about 4 miles an hour in the open reaches of the
middle river.
Sudden freshets come down while the river is rising, but do
not continue long or cause much difficulty to the navigation.
Speaking generally, vessels which draw more than 4 to 5 feet
of water cannot ascend the river above Qurnah, except when
it is in flood. There are no difficulties between Basrah and
'Qm’nah, but the draught of vessels proceeding to Qurnah is