'REPORT ON THE ADMINISTRATION OF THE BOMBAY PRESIDENCY, FOR THE YEAR 1907-1908' [‎52r] (102/137)

IRRIGATION.
IRRIGATION. go
ThGi’6 w^s £tn increase of *5,4/1 acres in the area on Major Protective Worhs as compared.
. , the average of the last 10 years and a very large increase of Rs. 1,54,188 in the cross
Wlt ^sed revenue. The small decrease in the area of the Nira Canal is due partly to the^fact
the supply was insufficient to meet the full demand in the rabi season and partly to the
j and for water for monsoon crops being low owing to seasonable rainfall. The gross' revenue
however, the largest on record.
Owing to breaches in the Nira Canal the Shetphal Tank could not be filled and water
Id therefore not be given for rabi crops outside the blocks for which there was much demand.
fioures given by the Executive Engineer for the Mhaswad Tank are only approximate, but
there appears to he a very substantial and satisfactory increase in both the area and revenue
due principally to increased rates and to demand for water owing to want of timely rainfall.
In the case of Productive works collectively the area irrigated was about the average of the
1 st 10 years but there was a substantial rise of over Rs. o5,000 on the gross assessed revenue.
Tor Ekruk Tank, the area and revenue are the largest on record. On the Kadwa River system
there was a rise in the revenue of about Rs. 3,391.
Under Minor Works and Navigation there is an increase in the area and a substantial rise
of Rs. H°00 in the revenue. Most of the works contribute to this but there is a falling off
both in area and revenue in the case of the Matoba Tank and Ojhar Canal. This is due in
both cases to the want of demand for water for monsoon crops owing to the seasonable rainfall
in the early part of the rainy season. The slight falling off in the area in the case of the
Bhadalwadi Tank is due to short supply in the tank during the rabi season, but Shirsuphal
Tank on the contrary shows an increase due to better supply in the rabi season. The Mhaswa
Tank, Jamda Canals, Parsul Tank and Bhatodi Tank, the Sholapur Tanks—Ashti, Koregaon
and Pathri, all show satisfactory increases, that of Ashti being most marked and being due to
monsoon rain providing replenishments which were used as the rabi rains failed. On the whole,
the increase in area under the Heads Major Works—Protective, Productive, and Minor Works
amounted to 8,099 acres and the increase in revenue to Rs. 2,44,963.
(6) Important events which have occurred concerning works.
There were no events of much importance to record during the year. The rainfall generally
was not very satisfactory, the late rains failing in most places. Bxceptionallv heavy and intense
rainfall fell at ShoMpur on July 16th when 6-36 inches fell in 4£ hours. The Executive Engineer
reports that the Negretti and Zambra automatic rain-gauge in the compound of his office
plainly showed that from 8-15 to 10-30 P.m. the rainfall was 5-87 inches or at the rate of 2;6
inches per hour for 2£ hours. To show how variable the rainfall in this tract of country is,
the rainfall at Hiperga 5 miles away was only 4’36 inches and it did not extend over the
catchment area of the Ekruk Tank which received a replenishment of 3 feet depth only.
(c) Engineering questions that have arisen.
Twelve automatic gates similar to those which have proved so satisfactory at Lake Fife
have been erected at the Waghad Tank and 68 similar gates for the masonry dam at Chankapur
have been received from England and are being taken to the site and it is hoped will be erected
next working season. The experiments made to ascertain the line of saturation of various
earthen dams were continued.
The Executive Engineer, Sholapur, has made some careful experiments regarding the
losses by evaporation and absorption in the case of the Pathri Tank. This tank was selected,
as at present a very small discharge is being let out. for irrigation, so that the losses were less
likely to be influenced by any possibility of error in the discharge from the tank. I he resu s
are given in the following table and would seem to show that the losses are really muc
more than bave been generally allowed for in Tank projects in the Deccan :
Table showing the observed depth of losses in feet due to evaporation and absorption in
[
January.
February.
March,
April.
May.
O
{=1
P
”3
•“5
August.
S
s
a>
P,
<33
CO
October.
November.
December.
Total.
0-65
0-59
0*91
1-08
1-14
078
0 , 34
0-34
0‘4G
1-00
0‘70
0-72
8*71
The failure of the October rains no doubt accounted for the a ,
that month. The somewhat low figures for the months of July, August an ep em er ^ >
the Executive Engineer thinks and this is no doubt the case, due to small rainla ovei ie
the tank itself which did not produce any run-off from the catchment an so
apparent decrease in evaporation and absorption. Experiments were also ma e ° .
losses on the Mhaswad Canal due to evaporation and absorption by gauging . e ^ T
sections when all the outlets were closed. The results are shown below m equivalent di^cnaiges
expressed in cubic feet per second for each million square feet of wetted suiiace o can
Canal.
Losses.
Length.
C a secs.
Miles.
Main Canal No. 1
6-14
10
Main Canal No. 2
7*65
i7’75
Kasegaon Branch
6-50
18‘25
Pandharpur Branch
6-34
6'00
Chap. IV.
PRODUCTION
AND
distribution.