‘Persia – especially Seistan’ [‎123v] (245/949)

2
I’s note speaks for itself, and I will P r . e ^ U ^^ever, point
nclusions of an irrigation expert. I ’ ^ ma te of the
e 1 an
an
* More accurate surveys since made prove the
commandable area of culturable laud to he consider
ably in excess of this figure.
A H. McMahon.
f The observations made by Mr. Ward regarding
the excellent quality of the land and the rich ferti
lising quality of the Helmand water deserve notice.
A. H. McMahon.
to criticise
9. Mr. Ward
the opinion or conclusions 01 an irrigation expert, j- ” V T'~7 es timate
out that Mr. Ward has based his conclusions on a very modes volume
average volume of the Helmand River. The average 1 ? inl vo i u me of
calculated by him, i.e. 9 2,000 to 3,000 cusecs, is much less t an ^ begin-
water we found in the river (4,000 cusecs) when we first me i ^ ^ ^
ning of February, and at a time when local information s i loWe .^ avo iding
normal minimum height. Notwithstanding this care, however, i g p j man( ^
overestimate, it has been shown that, with proper control ol e ^ } anc if
area of over 3 , 000,000 am t r
can be commanded, of ^ lch ® J™;
i.e., 7,50,000 acres, of spring P
still larger area of autumn c p
fully irrigated each year. I am mcli
to think that this is, if anything, n
underestimate; hut, assuming that it is not so, the figures sta e su
demonstrate the important results which would be obtained ^7 c( ^ n 10 , 1 N x
Helmand River above Seistan. Rough measurements show that on y
75,000 acres of commanded land in Persian and Afghan Seistan aie now un er
spring crop cultivation. As above shown, ten times this area can e ma e
capable of such cultivation.
10. Mr. Ward has shown that the works required to obtain effective
control are of a comparatively simple nature. Briefly stated, these works can
take one or other of the following forms, i.e .,—
(i) A temporary "weir of the ordinary local type near Chahar Burjak,J
^ £ 11 miles above Band-i-
shingle. Kamal Khan, to nil a canal
A. h. McMahon. on left hank to irrigate
the Tarakun tract, and a canal on the right bank to irrigate the
Killa-i-Eath and Sar-o-Tar tract.
(ii) A permanent weir, with above canals at the same place, to effect the
above objects, and also divert, if required, the whole or part of
the Helmand River or its flood-water into the Gaud-i-Zirreh, by
an escape channel through nulla, which, for w T ant of a local
name, we have called “ Johns nulla”. The cutting required for
this escape channel from the point where it would leave the
above canal, would he 4 miles in length and of maximum, hut
not constant, depth of 20 feet.
(iii) A masonry dam at Bandi-i-Kamal Khan to raise the ordinary river
level about 11 feet and effect the objects noted in (i), or, with the
above escape channel, the objects noted at (ii).
All cutting required would he in easy soil, and the distributary canals
offer no difficulty owing to the open level nature of the country.
31. The figures given in statement A of Mr. Ward’s note, Appendix E,
§ To arrive at the culturable areas, deduct 20 o / o as show the gross§ areas of land in Persian
ahown m paragraph 4 of Mr. Ward 1 s note. and Afghan Seistan now commanded by
A ’ H ‘ Mc ^ Iahon - existing canals, and those commandahle
if the river ^_ eie c ^ n ^ r ^ e( ^‘ ^ ie t gross commandable area in Persian
Seistan, only 772, out ot 2,o33 square miles, are now commanded, and in Afghan
limits only 546 square miles out of 3,360. The control of the Helmand would
thus enable t e nrigation of an additional 1,761 square miles of land in
Persian tern ory, an , 14 square miles in Afghan territory, of which no less
|| Our new surveys show that a much larger figure ^ ian 8,4001| Square miles are Comprised U1
than 840 square miles might be inserted here. The the desert tract of Sar- 0 -Tai\ &C., east
exact area has not been jet worked out. 4-1 tt i i x ii ’ -i’ ii
a. h. McMahon. ot Heimand. In other words, the
,, , t . , Persian commandahle area could he more
than quadrupled, and that within Afghan limits increased to over six times its
present exten ,wi eat the same time the comparatively small areas already
cultiva tc non e len eie immune from the serious damage and destruction
to which they are now liable m years of a high river.