Water and Infrastructure Development Water Distribution
System and its Management
Title: A case
study of a successful efficient, equitable distribution of irrigation water at
Indore Minor Irrigation Tank, Tq. Dindori, Dist. Nashik. having potential of great
revolution in water distribution System , practical way and method of adopting
this on larger area in command area .
Author : Arun
Anantrao Ghate A.M.I.E.(India),
LL.B Assistant Engineer , working in the
office of Chief Engineer and Chief Administrator, Command Area Development
Authority, Water Resources Department GoM Aurangabad (Maharashtra).
Address : c/o CE & CA, CADA Office, Garkheda Near Gajananmaharaj
Temple Aurangabad. Pin 431005 Email:
ghate2087@gmail.com
Phone 0240 2331095 ,
2356579, fax 02402342331M 9890203442
ABSTRACT :
There are lot of innovations found in design and construction
of dams for irrigation but when question of distributing this stored water
arises, there are no much innovation. In Maharashtra there are no new sites to
be exploited for large dams. Increasing area under irrigation by construction
new dams may not be possible in future but it is possible to use and adopt new
and simple innovative pipe distribution system to save conveyance losses and
thus there is a lot of scope to increase efficiency of conveyance system. By
adopting this new method of distribution at least 30 to 40% more land could be
brought under irrigation without investing any more on construction of new
dams. The innovative distribution system designed and constructed by group of
farmers by forming Water Users Association is unique example of simple but
efficient water distribution system adopted at Indore Minor Irrigation Tank Tq.
Dindori, Dist. Nasik . Due to this method water loss in conveyance system is
almost eliminated resulted in increasing area of irrigation twice. Equitable,
proportionate and assured water distribution resulted in enhanced confidence in
farmer to grow value added crops like grapes. Conjunctive use of well water
resulted in overall increase in crop yields. By using the basic principles of
this theme the author have proposed a new and innovative distribution system on
canal irrigation on larger scale. The area of 1000 hector is selected for this
study and all details of pipe line distribution are planned and designed
including estimating its cost also. The cost comparisons are also carried by
designing same area by conventional Open Canal Distribution system. It is found
that pipe line distribution does not cost more than open canal distribution
system but pipe line distribution system will eliminate following lacuna in
conventional open canal water distribution
system such as (i) Unequal distribution resulting in using more water on
less area (ii) Tremendous losses in conveyance system (iii) Head portion gets
more water and tail end gets no water (iv) Difficulty in preventing defaulter
framer from taking water from water course . The new system now proposed
will increase irrigation efficiency up
to 98 % which is 40% in present open canal system.
Introduction:
The total geographical
area of Maharashtra State is 30.8 Million hector, out of which 22.5 Million
hectors are cultivable. The irrigation potential created up to end of year 2011
in Maharashtra is 4.634 Million hectors. There is considerable gap between the
potential created and actual utilization. Efforts are being made to bridge the
gap between potential created and utilization. The state economy is dependent
upon the agriculture production and irrigation facilities are regarded as the
key element of irrigated agriculture. To fulfill the need of food and fiber of
growing populations, it is very
necessary to use water judiciously on equitable basis. In Maharashtra State
most of the sites are already taped. Hence there is no scope to bring more area
under irrigation by constructing new dams. The only option available is to
improve efficiency of conveyance system and to save water. It is generally
observed that 50 to 60% water loss is occurred in conveyance system. Majority
conveyance losses occurred in distribution network. To avoid these losses a
total underground pipeline network is proposed. This pipeline network is based
on the theme of already constructed and executed system at Indore Minor
Irrigation Tank, Tq. Dindori, Dist. Nashik. This system at Indore is running
smoothly from last 7 to 8 years successfully and efficiently. The planning of
Indore M.I. tank and its experience is
to be considered first so that further extension of this concept on larger area
would be easy. At Indore the pipe line
distribution is carried out for 115 Hector area and water is pumped by using 50
H.P. pumps to main distribution chamber. In this paper the proposed pipe line
network system is totally based on gravity flow and there is no need of
electricity to run this system. The proposed system is planned for 1000 Hector
in a command area of Tapi basin between two local nalla . This system is
proposed to be executed on pilot basis and after evolution further
modifications, if required will be made in future planning.
Success story of Indore M.I. Tank’s
pipeline distribution :
The Indore village is situated 25 km. away from the
district headquarter (Nashik) Maharashtra (India). The water resource
department constructed a minor irrigation tank in 1989 having gross storage
capacity of 0.89 million cubic meters. Two irrigation sluices were provided on
left and right flank side to irrigate 115 hector. Initially the management of
the project is handled by the Water Resourced Department. The maintenance,
repairs and operation was done departmentally by water resources department.
Irrigation was done in the rabi season i.e. October to February. Hot weather
irrigation was not possible as tank was getting empty in two or three
irrigation rotation. Due to insufficient and uncertain water supplying from the
reservoir, the yield of crops were not enough.
taking over management by Water Users
Association:
To overcome the problems of shortage of water, the
beneficiaries united together. After lot of discussion and brain storming it is
decided that (i) Water users association to take over the management of
irrigation in their hand. (ii) To reduce the conveyance losses in the open
channel, it is decided to close the sluice on right and left canal and to
distribute the water only through underground pipe distribution network. (iii)
Group of 3 to 7 farmers having fields side by side or as convenient are to be
formed and each such group will carry water through common pipe from elevated
main distribution chamber to field level small distribution chamber. Every
individual will laid a separate pipe line from small distribution chamber to
their own field at their own cost.
The water user association have constructed a main
distribution chamber of 3 m. diameter and having a depth of 2 m. A pieces of
PVC pipe having 63mm. diameter and 115 numbers are fixed in vertical wall all
at equal level along the circumference of main distribution chamber. They work
as a outlet. Each pipe represent 1 hector area and it is called one share. (The
photograph-1 shows the pipe and circular chamber). The 115 share holders thus
get water in equal and proportionate basis through 115 pipe outlet. Further
individual distribution among small group of 3 to 7 were done by similar small
distribution chambers constructed on the higher ground. (As shown in
photograph-2). The small distribution chamber finally distributes water to
individual farmer according to their share holding by making compartment in small
distribution chamber as shown in drawing. Thus all the share holders get water
at a time on equal and proportionate basis due to this unique method. This
system resulted in almost no conveyance loss and farmers used this saved water
to enhance their irrigation to other lands. Finally when irrigation department
calculated the irrigation potential of 115 hectors farmers have succeeded in
irrigating land of 287 hectors In actual. The farmers have used this water by
drippers and sprinklers hence it can be conclude that if conveyance losses and
modern technique of water utilization were used then irrigation could be doubled.
A group of farmers at
Indore Tq. Dindori Dist. Nashik have designed and implemented a simple, cost
effective, efficient, equitable pipe distribution system as shown below
Photograph-1 shows Main
Distribution Chamber and vertical pipe carries water to Small Distribution
Chamber
Photo No.2 Small Distribution Chamber of Small
group of 3 to 7 farmers.
Photo
no. 4 shows Equal Diameter Pipes fixed at equal level distributing equal quantity of water
Water from this chamber is distributed through equal diameter equal level
pipes on circumference of circular chamber as shown above photo no.3 and 4 .
All pipes is having equal diameter of 63 millimeter at equal level hence each
pipe get equal quantity of water. One pipe is provided for one hector. At
Indore this system is made for 115 hector therefore 115 pipes of 63 millimeter are provided. They have
constructed an outer ring and have made small compartment according to their
group and convenience as shown in photograph above . Water is then carried out
to respective group through pipe line and further field level distribution is
again done by similar method but at higher ground level with small
chambers. By adopting this system this
group succeeded in doubling the area in saved water.
In this system there is no head or
tail reach. All the farmers gets water at a time on equal and proportionate
basis. There is no any structure, no land acquisition and as system is
underground it is free from interference of men, cattle or machinery. The
defaulter farmer is easily prevented by capping his pipe at main distribution
point itself. No costly maintenance is required. Man power required for
management is also reduced as there is no frequent opening and closing of
outlets.
Taking the inspiration and
clue the author have suggested pipe line distribution method for large area of
1000 hector. The main distribution on equal and proportionate basis is to be
done on the same principle near Head Regulator as shown in drawing. The ten
pipes will carry water to main circular distribution chamber by gravity. A
discharge received from head regulator will be distributed equally and
proportionally by fitting pipes of equal diameter at equal level .The diameter
of pipes will be so designed that it will carry a discharge sufficient to feed
discharge of main distribution chamber.
The main distribution chamber will distribute water to small
distribution named as sub distribution chamber.
Method and ways to use Indore System on larger area of 1000 hectOR.
:-
At Indore Minor Irrigation
Tank the water conveyed up to Main Distribution chamber is through rising main
of 300 mm. of P.V.C. pipe by help of 50 H.P. For pumping of water the scare
electricity is consumed. The author have planned and designed a pipeline
distribution system on pilot basis for 1000 hector by gravity flow. Thus in
this proposed new system there is no use of electricity. For this purpose one
Minor from command area of Tapi Narmada Project, Tq. Shahada, Dist. Nandurbar is
selected. The command area is divided in 10 blocks.
The minimum area of block
is 38 hector and maximum area of block is 130 hector. On an average 100 hector area
per block is provided. This system is designed on the basis of crop water
requirement of an one liter per second /hector . The total distribution between
10 blocks is distributed at Head Distribution Chamber by making compartment.
The equal pipes of 150 mm diameter will be provided at equal level for 15 Hector area . For
example for 90 hector area one compartment of 6 pipes will be provided as shown below. (Two rows are shown
in cross section to size of chamber for economy)
Figure shows section of
Head Distribution Chamber and
pipe leading to Main
Distribution Chamber
Figure shows the Head Distribution chamber ,
Main Distribution chamber and Small
Distribution Chambers and its interconnections.
Block Level Distribution :- Water from Head
Distribution Chamber will be carried to elevated Main distribution chambers
similar to Indore M. I. Tank. At this chamber equal diameter pipe of 63 mm will
be placed at equal level. Thus if a particular chamber is provided for 100
hect. then 100 PVC pieced of pipes of 63 mm. will be placed equal level. From
this elevated chamber the water will be carried out to farmers field either
individually or by creating group of 3 to 7 farmers. Field level distribution
is again done on similar logic by constructing small ground chamber and making
compartment according to individual share. Compartment according to share will
be prepared at outlet sides and thus water up to individual level on equal and
proportionate basis on entire area of 1000 hector at a time.
The new pipe line
distribution system is economical than open
canal system as seen below which is worked out by detailed design and estimate.
Cost Comparison of open canal water
distribution system with pipe line distribution system.
Open Canal Water Distribution
System
|
Cost in Laces
|
Pipe Line Distribution System
|
Cost in Laces
|
|
33.41
|
1. Earthwork
|
26.00
|
|
174.97
|
2. Providing and
supplying pipes of various diameter
|
308.17
|
|
149.39
|
3. Lowering and laying
of pipes
|
33.55
|
|
119.76
|
4. Head distribution
chamber
|
6.00
|
5.Main elevated
distribution chambers
|
9.00
|
||
6.Small distribution
Chambers
|
100.0
|
||
Total
|
477.53
|
482.72
|
CONVENTIONAL WATER DISTRIBUTION SYSTEM AND ITS LIMITATIONS:
In Maharashtra state on majority part of
command area, a conventional Open Water Distribution System consisting of Distributory,
Minor, outlets , field channels and turnout is provided . Water required for
one chalk of 15 to 20 Hectors area is
released at outlet head and further distribution between 10 to 15 farmers is
left to themselves . This conventional system is having following shortcoming.
(1) Whole system is open to sky hence open to
interference to anybody. This “Open to All” system therefore, requires a lot of
manpower for maintenance and management. The farmers at head reach portions
takes water even though rule is tail to head. This inequality in distribution
resulted in social unrest, use of more water on less area wastage of water on
large scale.
(2) Water to 10 to 15 farmers are given
without deciding individual’s share
(3) Open canal requires number of
structures such as falls, road bridges, outlets, turnouts.
(4) Defaulter cannot be prevented from taking
water because it is difficult to prevent them due to remote inaccessible area
and domination of local farmers.
(5) Volumetric distribution to each farmer is
not possible efficiently as measuring water in open canal is not so easy in
field as water head is constantly changing , hence crop area is measured every
time. This resulted in repetition of work. No encouragement to use less water
on large area possible.
(6) For minor,
field channel certain land width is necessary, acquiring small strip of land is
having same hurdles that of large piece of land. The open canal system have to
follow certain gradient and ridges, the land under cultivation gets divided due
to minors and creates obstacles in land framing actives. Pipeline distribution
system eliminates this drawback of the system, as no land acquisition is
required for pipeline . The speed of work will be more and there will be no disturbance in farming . In open canal
system all types of agriculture waste such as leaves and remains of crops
easily mixes with flowing water. This debris accumulates in christen of falls
and water cushion effect is hampered , the energy dissipation does not happens
effectively and it results in increasing velocity of canal flow. Removing of
debris in fall increase operation and maintenance cost.
(7) In open canal
system distribution of water to different chalk does not remains in proportion
to area of land. The discharge is a function
of driving head. A simple obstacle in open flow changes driving head instantly.
Due to this obstruction the flow could not remain in proportion to area of
land. In pipeline distribution system distribution is done perfectly in a
chamber in proportion of area of land and hence , there is no any chance of
unequal distribution. The perfectness in
distribution results in equality. Due to equal and proportional distribution in
respect of area of land result in judicious use of water.
(8) In Maharashtra the
present practice of water charges is based on “area irrigated” instead of
volumetric basis The electricity boards count units consumed by the customer
similarly the telephone service provider
counts talk time where as water resource department counts the area of crops
under irrigation . Naturally the tendency of using more water on less area is
grown. This resulted in inefficient use of water. The exact counting of water
in open canal system is also difficult as depth of flowing water doesn’t
remains constant. In pipeline distribution system this measuring of water is
very simple and unique. The water up to head distribution chamber is easily
counted with the help of water meter. Further measuring of water is not
necessary as it can be done by dividing supplied quantity to number
of open of opening. Thus by simply counting number of open pipe quantum of
water can be counted accurately.
Conclusion: - For increasing water distribution efficiency the
distribution method should be improved. Distribution at centralized water
distribution chamber is one of the method proposed for larger area. Simple
Pipeline distribution method which is easy to construct ,easy to understand ,
easy to operate by the farmers is proposed.
