Coll 29/40 'Seistan: sale of consulate land' [‎7r] (13/443)

* vide
photOGTH p
ettached.
4
flooding and 1 understand that that is the case as far as
Kohl ak, which is now the extreme southerynost limit of the
Harnun-i-Fuza. It seems clear, therefore! that the process
of raising of the mouth of the river by silting, the most
important factor making for* a change of course, is to
day far advanced.
(2) in the past it has been necessary to construct a
Aeir across tna iielmand at KuhaK to turn the water A nto
the ;ud-i-Seistan (Nurab) channel for irrigation. In the
Vvords of the He^enue 'Report " Such weira are necessary,
not only to divert a sufficient amount of water into the
distributary channel, but because the bed of such a
channel at its head is always higher than the bed of the
• larent river. This results* from the deposits of silt at
that point owing to the slackening off the velocity of the
water as it leaves the mein stream".
For the lest 3 years it has not been found nece
ssary to construct the weir across the Helmand at Kuhuk,
more than sufficient water turning to the md-i-heistan
(Hurab) of its own accord. Further, the oed of the
Rud-i-leistan where it joins the "main stream" is now
definitely lower than that of the latter, und the water
turning into the Rud-i-^eistan has a noticeably faster
current than that which flows straight on. One would
therefore expect a bar of s?ilt to oe formed ecrosss the
itbca bed of the "mam stream* here. That, this is, in
fact, the case is borne out by the resence last winter
of an easv ford (less than 3 1 deep) across the "main
stream" wriere the Rud-i-Seisten takes off, while the
latter never became fordable.*"It should be borne in mind
a that the bed of a diatributnry river in its delta rises
steadily by the silt deposited; the change of channel is
therefore originally due to the rise of 1 vel of the old
channel making it possible for the water to ureak away
down on a new and lower channel; a new distributary
c&nnot oe formed by Scour until the old diatriouiary has
obtained command over the oeu of the newly to be formed
distributary".(5^ From m own observation I can vouch for
the fact tnat of the Rud-i-Seiatan and the Rud-i-ianun
the former is definitely the deeper and im a xatat the faster
current at Kuhak, where the two streams separate.
(3) Past changes in the rx^tltAxac river’s course seem
always to have taken place in years of high flood;Co)and
1939 wee a year of greater floods than had been seen in a
generation, in the spring of that year big floods found
their my down the fcur&b channel and the stone bridge over
it near iaoul was washed away. The Hueuainki canal system
also flooded severely and -^duI was nearly flooded from the
iast in consequence/
Chapter XXXI11 page 134/1 he
irrigation Report ^ol I ctr~
pci^e 15
Ceistan pp.163,173 & 1?7
Revenue Report 7ol I chap.L
page 319
uuo Tat rorPi v "not trac eaoTe
on the
) nor it is readily
/traccaole eleewhere