Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 1
DESIGN CONCEPT REPORT FOR REHAB/REPLACEMENT OF PUMPING
MACHINERY OF RGLC SYSTEM
1. INTRODUCTION
In the AFD financed Jodhpur Reorg. UWS Project, it has been envisaged to
enhance capacity of RGLC conveyance system by replacement of 27
pumping sets installed in phase-I of RGLC along with replacement of
transformers, other appurtenances of pumping station. Some minor civil
works related to raising of escapes at PS & siphons have also been
included in sanction.
The feasibility report did not envisage any enhancement in capacity of
canal or to lay a parallel pipe line. The free board in canal is to be kept a
minimum of 0.45m even with increased capacity of pumps.
It is proposed to meet prospective demand of UWSS Jodhpur for the
design year 2029 but the enroute drawal of 930 (now 1204 villages) & 4
towns has been freezed for design year 2016.
The works included in the sanctioned package were to be taken up
through two separate goods contract. Apart from meeting increased
demand (Year 2029) of Urban WSS Jodhpur, another prime objective is to
reduce energy cost by opting for energy efficient system.
The requirement of making two separate goods contract due to absence of
assured funding does not exist now as AFD has singed one more
agreement to finance works of the whole Rs. 740.00 crores project with
assured funding. It has now been decided to combine two goods contract
into one DBOM contract incorporating clause of guaranteed maximum
energy consumption per ML of water handled by pumps during O & M
period of 10 years by bidders.
2. SUSTAINABILITY OF RGLC CONVEYANCE SYSTEM TO MEET YEAR
2029 DEMAND
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
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A preliminary design report to assess the sustainability of RGLC
conveyance system has been prepared and submitted in July-2013 mainly
to approve input data for design of system along with approval of
discharge capacity for each pump to be replaced at all the 8 PS. In absence
of authentic data, following assumptions were made in preparing the
sustainability report, which shall be reviewed/modified during detailed
design report of the package and compliance to observations of client, if
any, would be incorporated. The approval to above is required to proceed
with the detailed engineering.
2.1. No measurements have ever been made regarding seepage and
evaporation losses in canal. The department had entrusted the job
of determining flow of canal in different reaches to MBM
Engineering College to make a rough assessment of the seepage &
evaporation losses in canal. However, sustainability calculations
were done considering seepage & evaporation losses @ 0.96
cumec/million sqm wetted area as per decision taken in the
meeting held in chamber of Chief Engineer (Project) PHED,
Jodhpur on 23/05/2013.
2.2. It has been assumed that increased capacity of Phase-I pumping
sets is techno economically feasible for which necessary
modifications in suction piping & sump pits, if required, would be
carried out by bidders in consultation with the pump
manufacturer.
Accordingly, the designed discharge for Phase-I pumps to be
replaced has been calculated. Further, it has been worked out that
with increase in discharge of pumps (Phase-I) in year 2014 and
Phase-II in year 2020, the capacity of canal is adequate in all
reaches and a minimum free board of 0.45m is available in all
reaches of canal.
2.3. The sustainability of conveyance system has been worked out
assuming that discharge capacity of Phase-II pumps will remain
same till year 2020 as in absence of proper energy audit for each
pump, reliable data of their current performance and flow capacity
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
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is not available. However, it has been assumed that Phase-II
pumps, which have deteriorated or likely to deteriorate before
2020 may also be replaced in current package mainly to achieve
the objective of energy saving. The efficiency of existing phase-II
pumps is being determined on sample basis through
thermodynamic principle as flow measurement through
conventional UT/FBEM meters is not accurate for individual pump
set as observed from unofficial test data obtained from SMEC as
well as some observations made by a team of M/s Grundfos &
department.
2.4. The sustainability was assessed considering no parallel pumping
mains/siphons for increased discharge as investment on parallel
pipes would be much higher than extra energy charges. Only
strengthening of thrust blocks & water hammer control devices
may be required for phase-I pumping main, which is considered
feasible. Similarly, capacity of existing siphons is proposed to be
increased by allowing higher heading up at U/s of siphon for
which canal banks (Dowla) height can be increased, if required.
This option is cheaper than providing a parallel siphon.
2.5. No modification in CD structures like siphons, super passage
VRB’s has been envisaged and only canal siphons aqueducts,
escapes & rainwater out let structures have been considered for
modification wherever required.
2.6. It is proposed to increase capacity of Phase-I pumps being
replaced. The capacity of Phase-II pumps, if required to be
replaced for energy efficiency will be provided of same duty
condition to operate with the existing motors. Thus, as against
total increased flow requirement of 9.773 cumecs in year 2029, the
increased flow requirement up to year 2020 is only 8.923 cumecs
i.e. 10.54% increase over present designed flow of 8.072 cumecs. It
is proposed to check, design of all components for 8.923 cumecs
flow at 0RD of RGLC and wherever, modification in capacity of
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 4
existing structure is required, it shall be designed for ultimate
demand of year 2029 i.e. 9.773 cumecs.
3. DESIGN CONCEPT FOR DETAILS ENGINEERING OF RGLC PACKAGE
In absence of proper energy audit pump performance data precise data for
seepage losses in different sections of canal, an attempt is made here
under to develop a design concept to be followed for detailed engineering.
3.1. Design demand and flow requirement
3.1.1 Enroute Demand
As per feasibility report and as per decision conveyed in the CE(P)
meeting held on 23/05/2013 the enroute demand is to be
restricted for design year 2016. The designed enroute drawal for
4 towns and 1206 villages has been estimated as 242 MLD i..e.
2.914 cumecs as per table 2.0 of BCSR.
Although, the system capacity of enroute schemes is much
higher than its designed 2016 demand, it will have to be ensured
that either enroute drawal would be restricted to the quantity
indicated in BCSR for each enroute drawal point or by 2016, a
parallel system would be available to meet increase in enroute
demand.
3.1.2 Urban Jodhpur Demand
The demand of Urban Jodhpur for horizon year 2029 is 5.488
cumec (equivalent 417 MLD) as per table 1 & 3 which is apart
from ground water and recycled water to be utilized. The urban
demand of RGLC is to be drawn at two points i.e. at Indroka
silting basin for Surpura head works and at tail of RGLC system
in Kailana Lake. The capacity of gravity pipeline from Indroka to
Surpura is freezed as per the capacity of pipe line being laid
under this project. Similarly, the capacity of RGLC system at tail
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
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is also freezed by installation of new pump sets at PS-8
(replacement of Phase-I pumps).
3.1.3 Variation in demand – Shortfall in projection from RGLC
Although, the estimation of prospective demand of various
enroute beneficiaries & urban Jodhpur has been projected
meticulously, yet sustainability of RGLC system to meet 2029
designed demand is dependent on many variables as described
below :
(a) The most uncertain factor is correct estimation of seepage
losses for the present & it’s safe estimation up to horizon year
2029.
The seepage losses may be much higher if canal is not
regularly maintained/rehabilitated properly up to year 2029
or may improve if maintenance of canal is done diligently by
timely de-weeding/de-silting and repair to damaged lining as
well as to its earthen sections/embankment.
However, if losses are progressively observed to be more than
assumed values, there would be shortfall in availability at
Jodhpur, which is to be made good by managing recycled
water & ground water production and demand efficiently.
If it is observed that shortfall has to be made good from IGMC
only, the parallel system to be put in place for increased
enroute demand beyond 2016, may have some built in
cushion to tide over such deficit in RGLC system, if any, up to
year 2029.
(b) Enroute drawal may be much more than designed demand
due to delay in implementation of parallel system from IGMC
getting delayed beyond yr. 2016 or restriction of service levels
to 55 LPCPD becomes non manageable. As per present
calculations, some allowance would be available beyond year
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
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2016 up to year 2020 when Phase-II pumps are to be replaced
by higher discharge pumps. If seepage losses can be controlled
by better & dedicated measures, surplus water can take care
of increase in enroute demand.
Thus, in the contingencies of higher than envisaged seepage
losses, higher than designed enroute drawal or higher demand
of UWSS Jodhpur in year 2029 can be taken care of by either
efficiently managing seepage losses in canal or putting parallel
system from IGMC by 2016 and/or managing recycled
/groundwater as well as managing demand by IEC activities.
(c) The storage capacity available at Jodhpur (after discounting
Umed Sagar where heavy losses will occur due to large spread
area) would be around 20 days designed demand for year
2029. In order to match up with closure of IGMC, which is 30
days in a year, it would be appropriate either to use storage
capacity of IGM Canal or construct 10 days storage near
IGMC. This may facilitate running of canal for 345 days
instead of 335 days which shall give on additional quantity of
nearly 3.0%.
4. OUTLET CAPACITY AT RD 1109 OF IGMC :
As per the data made available the original outlet constructed under,
phase-I of RGLC is capable to deliver 264 cusecs (7.475 cumecs).
Similarly, the new outlet constructed in Phase-II of RGLC is capable to
deliver 62.5 cusecs (1.770 cumecs). Thus, the total capacity of two outlets
is 9.244 cumecs (326.5 cusecs) and is adequate to meet designed demand
up to year 2020. The capacity of outlet would require to be increased by
the year 2020, when phase-II pumps are to be replaced by higher
discharge pumps.
5. CONVEYANCE SYSTEM
5.1. Canal Portion
5.1.1 Seepage losses
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
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The canal has a lining of PCC blocks with sandwich plaster &
LDPE film in majority of length and CC lining (with LDPE film)/
masonry lining in some smaller sections. In the phase-I of RGLC,
the canal was designed considering seepage & evaporation losses
@ 1.2 cumecs/m sqm of wetted area. However, at the time of
RGLC Phase-II looking to better condition of canal, the seepage
losses were subsequently reduced to 0.72 cumecs/m sqm. In the
feasibility report of JRWSP in year 2009, while designing canal
system the seepage losses were increased to 0.96 cumecs/m sqm
of wetted area.
5.1.2 Measurement of seepage losses
No measurement were ever carried out about the extent of
seepage losses in RGLC in past.
5.1.2.1. Ponding method
The best method as adopted by IGNP is to determine seepage &
evaporation losses by ponding method during canal closure.
The IGMC also determine seepage losses by ponding method as
described in IS 9452 (part-I) 1980 & evaporation losses by pan
method as per IS 6939-1973.
The measurement of seepage losses in various section of RGLC
would only be possible now during next closure of canal for
which client is advised either to take help of skilled team of
IGNP or award a contract after inviting bids from experienced
firms.
5.1.2.2. Inflow – outflow method
This method normally applied to measure seepage losses in
running canal gives a very rough estimate of the losses in a
section of canal as it is very difficult to create an ideal regime
conditions of steady flow in a section having no enroute
withdrawal (or a properly metered withdrawal) over a reasonable
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
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time period to correctly assess the flow in a section & estimate
seepage losses. The flow in RGLC depends on rate of pumping
from U/s pumping station. The discharge of pump also varies a
lot, particularly an account of variation in sump level on suction
side as well as due to combination of different sets of pumps.
The fluctuation in frequency and continuous variation of total
head of pumping gives variation in flow by more than +5%.
Thus, it is not possible to create a steady flow regime in RGLC &
it is not possible to correctly assess quantity of water pumped
into canal over a particular time period.
Earlier, PHED entrusted the job of flow measurement in
different sections of canal to MBM Engineering College by
current meter. This study could not be completed due to some
reasons. Moreover, the accuracy of measurement of flow by
current meter would also depend on no. of observations made
across – a section of canal. The accuracy of velocity
measurement by current meter at a particular instance would
also be reportedly in the range of +10% as normally three
observations are taken across a cross section of canal.
5.1.2.3. Measurement of flow and estimation of seepage losses in
RGLC
In order to assess flow at a particular section use of ADCP –
working on Doppler principle, has been considered and as per
requirement of department, flow measurement at four different
locations were determined by portable ADCP on 1-8-2013. Apart
from flow across cross section of canal, area of flow & wetted
perimeter has also been calculated at a particular chainage of
canal for a particular instant of time. The details of
measurements are reproduced as under
Table-A : Measurement of flow in RGLC by Doppler principle using ADCP
Data measured by doppler test
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S. No.
Canal RD
Time Date
Max Depth
(in mtr.)
Top Width
(in mtr.)
Mean Velocity (in m/s)
Wetted perimeter (in mtr.)
Discharge (in cumec)
1 2 3 4 5 6 7 8 9
1 102.9 9:45 01/08/2013 1.61 5.978 0.859 6.8462 4.783
2 113.075 11.25 01/08/2013 1.51 5.631 0.974 6.5819 4.519
3 123.875 16.25 01/08/2013 1.48 5.325 1.034 6.1359 4.478
4 131.05 16.58 01/08/2013 1.58 5.566 0.869 6.3352 4.383
The above observation had been taken meticulously, and time
of observation was so selected so as to give same flow regime at
each section. However, despite best of efforts, the time lapse as
per velocity of flow observed varies by more than 10% and in
some instance, it is more than 200 to 300%.
Table – B : Seepage & evaporation losses calculation based on data
measured by Doppler test
S.
NO
.
Canal reach
Le
ng
th o
f re
ach
(i
n m
tr.)
Mea
n v
elo
city
in
th
e s
ect
ion
(i
n m
/s)
Tim
e r
eq
uir
ed
to
tra
ve
l a
s p
er
mea
n v
elo
city
(i
n s
ec.)
Act
ua
l ti
me
lap
se a
s p
er
tim
e
of
ob
serv
ati
on
(in
sec
.)
tim
e l
ap
se
err
or
Wa
ter
Lo
ss i
n
the
re
ach
(i
n c
um
.)
Mea
n w
ett
ed
P
eri
me
ter
in
the
re
ach
(in
m
tr.)
We
tted
are
a
(in
sq
. m.)
See
pa
ge
&
ev
apo
rati
on
lo
sses
(in
CU
M/M
SQ
M)
Sp
ot
1 R
D
Sp
ot
2 R
D
4=
(3-2
)*10
00
Av
g.
of
ve
loci
ty
fro
m S
po
t 1
to S
po
t 2
6=
4/5
8=
%((
6-7
)/7
)
Dif
fere
nce
in
ob
serv
ed
dis
cha
rge
at
Sp
ot1
an
d
spo
t 2
Av
g.
of
we
tted
p
eri
me
ter
fro
m S
po
t 1
to S
po
t 2
11=
10
X 4
12=
9/1
1*10
00
000
1 2 3 4 5 6 7 8 9 10 11 12
1 102.9 113.075 10175 0.92 11102 6000 85% 0.264 6.71 68315 3.864
2 113.075 123.875 10800 1.00 10757 18000 -40% 0.041 6.36 68676 0.597
3 123.875 131.05 7175 0.95 7541 1980 281% 0.095 6.24 44740 2.123
4 102.9 123.875 20975 0.96 21948 24000 -9% 0.305 6.53 136992 2.226
5 102.9 131.05 28150 0.93 30139 25980 16% 0.400 6.46 181732 2.201
6 113.075 131.05 17975 0.96 18743 19980 -6% 0.136 6.31 113416 1.199
Minimum seepage losses (in the reach no. 2) 0.597 CUM/MSQM
Maximum seepage losses (in the reach no. 1) 3.864 CUM/MSQM
Avg seepage losses of above 6 observations 2.035 CUM/MSQM
Avg seepage losses considering ±10% time lapse error (reach no. 4 and 6) 1.713 CUM/MSQM
Avg seepage losses considering ±50% time lapse error (reach no. 4,5 and 6) 1.556 CUM/MSQM
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
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As explained above, the seepage losses worked out above are
very approximate as steady flow regime conditions cannot be
generated through pumping system in RGLC and the flow
measurement by ADCP may also have accuracy level of +3 to
5% In addition to the flow measured at different section at
different time span may have variations of +10% due to
variation in pumps discharge. Thus, the losses determined
between various sections during a particular time span may
vary substantially and sometimes absurd results of getting
higher flow at downstream observations point is also observed
as was observed during flow measurements on 1/8/2013 by
ADCP when higher flow was measured at RD 123.875, when
observations were taken at around 1.00pm and it was found
that flow is higher than flow measured in U/s reach at RD
102.9/113.075 kms.
5.1.2.4. Literature on type of lining and seepage losses by Prof. B.S.
Thandaveswara of IIT, Madras
The above publication (Annexure-1) thoroughly analyses various
types of lining material & practices adopted in different states for
water courses, distributaries and main canals.
The author has described a vast no. of instances where due to
poor construction, supervision, quality & poor maintenance &
growth of aquatic weeds in canal, particularly in water courses,
have led to seepage losses almost equal to unlined canals with 4
to 7 years age. The performance of main canals & distributaries
which have less dry & wet cycles of rotation leading to less
cracking of lining in comparison to smaller distributaries & water
courses which have larger spells of dry runs. The longer dry runs
increases induced cracks in lining, leading to higher seepage.
It has been reported that combination lining of conventional
concrete/tile lining with PE films of 100-150 microns have
sustained water tightness in canals even upto 15 year life.
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
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The author has reported practices adopted in various
states/projects about seepage losses in lined canals, summary of
which is reproduced below :
Pact-C
S. No.
State organization
Adopted practice Seepage losses in cumecs/ msqm of
wetted area
Remark
1 UP (Lined trapezoidal)
seepage K1=1/200 (B+D)2/3 @ cumecs/km
0.293 B = 1.0m D = 2.0m
trapezoidal for 8 cumecs
2 Bhakra Nagal
(lined canal)
K1 = 1.25 Q0.056 (FPS) 0.523
3 Andhra Pradesh (lined canal)
0.60 cumecs/m sqm 0.600
4 Haryana (a) lined without LDPE (b) Lined with LDPE
0.43 0.16
5 Gujrat (a) Lined without LDPE (b) Lined with lDPE
1.00 0.80
6 West Bengal (a) Lined without LDPE (b) LDPE with soil cover
0.30 0.12
For rocky strata For rocky strata
The above table indicates that in different states, the seepage
losses after lining with LDPE film are predominantly considered
around 0.60 cumecs/m.sqm of wetted area. The literature
available on seepage losses also considers the value achievable
over a sustained period, provided canal is properly desilted
/deweeded & repaired/rehabilitated.
5.2. Field measurement of seepage losses in IGMC
The field test data for determining seepage losses in newly
constructed reaches of IGMC is available at Annexure 2 & 3. The
field tests have been conducted by ponding method and results of
tests are summarized below
S.
No.
Reach Type of
lining
FSD
(m)
Losses in cumecs m.sqm of
wetted area
Month
of
testing
Seepage evaporation Total
1 Suin sub
Br. 10.0 to
13.0 km
CC –
with
LDPE
film –
mehboob
2.3 0.2177 0.0086 0.2263 Dec-
05
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S.
No.
Reach Type of
lining
FSD
(m)
Losses in cumecs m.sqm of
wetted area
Month
of
testing
Seepage evaporation Total
section
2 Arjun
Minor 10.5
to 13.2 jm
-do- 0.46 0.1342 0.1236 0.2578 April-
05
The above test data is for newly constructed canal. However, the
IGNP canals are designed for 0.60 cumecs/m.sqm wetted area and
initial values are much below than the designed value & if canal is
properly maintained, the assumed figure is considered to be
achievable upto 25-30 years of life of canal.
5.3. Seepage and evaporation losses adopted in Narmada Main
Canal
The Central Water & Power Research Station (CWRPS) has
measured losses in Narmada Main canal to arrive at correct figures
of losses to be distributed proportionately amongst beneficiary
States. As per minutes of meeting held on 12/8/2010 of Narmada
Main Canal sub-committee (Anexure-4), the seepage & evaporation
losses determined in pre & post monsoon season have been given
as @ 0.70 cumec/million sqm & @ 0.65 cumecs/m sqm of wetted
area respectively. The average seepage & evaporation losses agreed
for determining proportionate quantity of losses is @ 0.67
cumecs/msqm of wetter area.
5.4. Recommended value of seepage and evaporation losses for
RGLC
Based on various data enumerated in foregoing para, following
conclusions can be drawn for RGLC system.
The determination of seepage & evaporation losses in RGLC
should be made a regular feature preferably by continuous
flow measurement at IGMC outlet, each PS and at tail of
RGLC by installing proper flow meters at appropriate
locations & at each enroute withdrawal point. This could be
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best done by the bidder who is to operate canal & its
pumping stations for 10 years.
The losses in different sections of canal should also be cross
verified/determined by ponding method during canal closure
period, preferably through an independent agency like IGNP,
or Quality Control wing of PHED.
The losses determined by inflow/outflow method through
flow measurements by ADCP is giving varying figures
ranging from 0.597 cumecs to 3.864 cumecs/msqm of
wetted area and therefore no precise conclusion can be
drawn as to what should be precise figures of seepage &
evaporation losses in the entire canal length and what would
be the losses in canal upto year 2029 (design horizon year
for canal conveyance system). However, based on data
available from other States, NMC & IGNP, it is to be
endeavored to maintain canal by regular desilting/deweeding
& maintenance of lining of canal in damaged portion at
regular intervals.
For the purpose of design of pumping & conveyance system
an average figure of 0.96 cumecs/msqm wetted area should
be adopted & all out efforts should be made to keep the
seepage & evaporation losses below 0.96 cumecs.
The two contingencies which can arise are
(a) Losses are more than 0.96 cumecs/msqm
As per report on sustainability of RGLC system, if the
losses are found to be more than 0.96 cumecs, higher
capacity pumping would be required in initial reaches
but the free board would be less than 0.45m in different
sectional reaches which is considered to be non feasible
as it may lead to more seepage losses in canal. Hence
higher pumping capacity over & above worked out with
0.96 cumecs losses would prove idle as canal would not
sustain higher flow.
This would further mean lesser availability in tail
reaches and pumping capacity in tail reaches would be
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
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slightly surplus. The investment on pumping sets of
higher capacity than required in tail reaches would be
negligible. However, surplus capacity in tail reaches
would facilitate better management of storage at
Kailana/Takhatsagar & Surpura Reservoirs. The
shortfall in quantity of water in tail reaches would
require mobilization of other measures like increasing
quantity of recycled water/ground water production &
better management of demand.
(b) Losses are less than 0.96 cumecs/msqm
The pumping capacity in head reaches would be slightly
surplus, the investment for which is negligible. This
would facilitate higher availability of water for enroute
drawal. The surplus capacity available of PS-8 would
facilitate better management of reservoirs Kailana/
Takhatsagar.
The condition of lining of canal appears to be good as even in
high filling (embankment) sections, no visible water logging
or seepage is observed along canal.
The de-silting & de-weeding operation are to be carried out
meticulously along with its periodical repair/rehabilitation of
lining to keep the losses well below 0.96 cumecs. As the
canal remain operative for almost 335 days in a year, the dry
run period is minimal & practically no cracks develop in
canal lining due to low wet & dry cycle.
Thus, canal conveyance system & corresponding pumping
machinery is to be designed for 0.96 cumecs/msqm.
5.5. Canal CD structures and appurtenances :
The CD work like canal escapes, siphons, aqueducts, inlet outlet
structure are to be checked for enhanced flow due to increase in
discharge capacity of Phase-I pumps being replaced. This would be
half of the total increase in flow envisaged for year 2029 when
Phase-II pumps would also be replaced after year 2020. The
designed increase in discharge of canal at 0 RD of RGLC to meet
designed demand of 2029 is 9.773 cumecs, but the CD structures
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etc would be checked for increased flow of 8.923 cumecs in canal
up to year 2020. This would save department an idle investment,
which is not likely to be used upto year 2020. However, wherever,
CD structures are inadequate to sustain 8.923 cumecs flow, the
modification in structure will be proposed for ultimate requirement
of 9.773 cumecs.
5.6. Mannig’s Rugosity coefficient
The RGLC is proposed to be designed as per Manning’s equation
for open channel flow. As per IS 10430, the value of Rugosity coeff.
‘n’ for concrete/PCC tile lined canals varies from 0.018 to 0.020. It
is proposed to adopt value of n as 0.018 as this is an important
canal which is required to be maintained properly & kept in sound
condition.
5.7. Maintenance of Canal
The RGLC is life line for urban town Jodhpur and a large no. of
enroute rural & urban population. It is therefore, of utmost
importance that canal is kept silt & weed free by regular cleaning
operations, particularly during closure of canal and necessary
repairs and rehabilitation works are carried out regularly to keep
canal in sound shape. However, the works of repairs and
rehabilitation cannot be identified at one stage for entire 10 years
O&M period. These are to be regularly assessed every year and
necessary measures be taken to keep the canal in top shape. The
canal banks, embankment and cutting section also get damaged
every year and are required to be attended regularly. The service
road and inspection banks are also required to be maintained
regularly for which need for repairs etc. have to be identified every
year and action taken to obtain sanction and get the work
executed. At present the A&F sanction does not include any
provision for these works which are of substantial magnitude as of
now.
In nutshell, it is not possible to define scope of work for repair and
rehabilitation of canal for a 10 years O&M contract. The bidders
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 16
who normally have expertise in O&M of pumping machinery and
pipeline seldom have expertise for maintenance and repair of
canal.
It is, therefore, proposed that a separate contract (s) for shorter
durations and shorter reaches/ canal section would give better
results and it would be possible to keep the canal in good condition
to contain seepage losses within the designed limits.
5.8. Conveyance through pipelines
The conveyance system of RGLC comprises of pipelines in a length
of 29.5 Kms. The pumping mains of PS 1 to 4 are for individual
pumps whereas for PS 5 to 8 two parallel combined pipelines have
been laid receiving water from multiple pumps sets.
5.8.1. Option of parallel pipelines to cater to increased flow
requirements
No provision has been made in the feasibility report and
administrative and financial sanction to provide for parallel
pipelines to cater for increased discharge of pumps. On the face
of it, it seems impractical to run the pipe lines in parallel as the
duty point head of Phase-I pumps and Phase-II pumps would
be different.
5.8.2. Calculation for friction head losses/bench marking present
energy consumption
It is proposed to adopt Colebrook’s equation in working out
friction head losses in pumping mains/Siphons pipes. The
value of roughness projection ‘k’ has been considered as
0.035mm as per water supply manual and friction losses have
been worked out accordingly. However, before finalizing head
requirement, precise head loss can also be got calculated from
the successful bidder. As per agency requirements, bench
marking for energy consumption in RGLC system is required to
be established prior to replacement of pumps etc. under this
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 17
package, which is proposed to be made part of the scope of
work under the DBO contract.
5.8.3. Control of water Hammer
The zero velocity valves have been installed at PS 5, 6 & 8 on
common headers. These valves are functioning properly. No
excessive positive surges have been observed during tripping at
various PS. However, the adequacy of zero velocity valves would
be ascertained through analysis for increased flow conditions in
phase –I & phase –II pipelines, wherever required. The need for
extra no. of zero velocity valve installed on phase –I pipelines
would be examined for increased flow and if required, extra zero
velocity valves would be removed.
For individual pumping mains at PS 1 to 4 surge towers would
be provided to release surge pressures and suitable provisions
would be made to provide anti siphon valves at delivery points
to save on energy and prevent excessive reverse flow
5.8.4. Thrust Block
The data related to existing thrust blocks regarding its
dimensions is not available. Sample calculation checks,
methodology for improvement in thrust blocks, wherever,
considered inadequate would be got finalized and successful
bidders would be asked to ascertain adequacy of thrust blocks
at his level before actually increasing the pumping capacity.
6. DESIGN CRITERIA FOR REPLACEMENT OF PUMPING SETS
6.1 Replacement strategy
The pumping sets installed in Phase-I of RGLC in Year 1996 are
proposed to be replaced to meet to higher discharge requirements to
meet increase in demand up to year 2029. In absence of proper
energy audit for phase –II pumping sets installed in year 2005, an
attempt has been made to draw inference from pump test data
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 18
available for few pumps from unofficial report of SMEC, 8 pumps
test data available on thermodynamic principle done by Secure
Meters. A few tests have also been conducted by a team of STC,
Department and Grundfos pumps. The summary of test results of
various tests conducted as above is given below :-
PS No.
Pum
p N
o.
Pump efficiency Slippages
Replacement recommended
or not Y/N
Rate
d a
s
per
Manufa
r.
As p
er
SM
EC
As p
er
Secure
mete
r
As p
er
Gru
ndfo
s/S
TC
SM
EC
Secure
mete
r
Gru
ndfo
s
1 14
15
16
85.0
85.0
85.0
83.07
85.71
87.35
-
-
82.60
-
-
-
(-)1.93
(+)0.71
(+)2.35
-
-
2.40
-
-
-
N
N
N
2 24
25 26
85.0
85.0 85.0
65.39
66.93 67.65
-
82.80 -
66.73
67.36 63.37
-19.61
-18.07 -17.35
-2.20 -18.27
-17.64 -21.63
Y
Y Y
3. 34
35
36
85.0
85.0
85.0
-
-
74.40
80.97
-
-
-
-
-
-
-
10.60
-4.03
-
-
-
-
-
Y
Y
Y
4. 44
45
46
85.0
85.0
85.0
-
60.83
58.92
70.90
-
-
78.38
72.27
-
-
-24.17
-26.08
14.10
-
-
-6.62
-12.76
-
Y
Y
Y
6 64
65
66
89.0
89.0
89.0
-
61.24
59.08
-
83.70
80.90
-
61.24
59.08
-
27.76
29.92
-
- 5.30
- 8.10
-
-
-
Y
Y
Y
7 74
75
76
88.0
88.0
88.0
74.42
75.60
76.01
79.0
-
-
60.11
63.26
59.41
13.58
12.40
11.99
9.00
-
-
-27.89
-24.74
-28.59
Y
Y
Y
8 84 85
86
82.88 82.88
82.88
74.35 74.93
74.73
- 75.40
-
- -
-
8.53 7.95
8.15
- 7.48
-
- -
-
Y Y
Y
Although, reliability of test results is not strong, yet looking to
better options available now in market in terms of higher efficiency
achievable on a sustainable basis with several types of coatings &
other treatment of pump sets, it is proposed to replace all pumping
sets whose efficiency has fallen below 80 % This will ensure that
bidder do not load his offer with capital investments required for
such replacements. The bidder is required to quote guaranteed
energy consumption/ML of water handled at each PS and is at
liberty to include in his offer for replacement of remaining pumps,
if bidder can fetch higher energy incentive by replacing remaining
pumping sets also.
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 19
As for PS-V, the department has recently replaced all six phase-I
pumps by same duty condition and therefore Ph-II pumps are to be
essentially replaced with higher discharge pumps to meet
increased demand.
The replacement of pumping machinery proposed therefore is
summarized as below:-
PS No Total no. of
Pumps
No of Pumps to be replaced
PH-I
(with higher Discharge)
PH-II Total
1
2
3
4
6
6
6
6
3
3
3
3
-
3
3
3
3
6
6
6
5
6
7
8
12
6
6
6
6
3
3
3
-
3
3
3
6
6
6
6
Total 54 27 18 45
6.2 Pump specific speed and NSPH required
It is proposed to increase the discharge of pumps of Ph-I to be
replaced by nearly 24% In order to meet requirement of higher
NPSH as well as to achieve better efficiency, the speed of pump is to
be reduced suitably or double volute pumps may have to be chosen
and bidder is to be given a free hand for opting speed of pumps
6.3 Pumps suction piping
The suction velocities in installation at PS1 to PS 3 may rise to
around 2.4m/sec Although, water supply manual recommends
limiting suction piping velocity to 1.80m/sec, but several pump
manufacturer’s & American Hydraulic Institute as well as many
reputed authors recommend higher velocities in suction piping.
Higher suction velocity would mainly increase loss of suction head
and limit NPSH available
As bidder is quoting offer with guaranteed energy input/ML at each
PS, it is prudent to leave it to bidder if he intends to replace such
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 20
losses in suction piping, valves, bell-mounts etc. On the face value
losses in suction piping are negligible and no substantial savings in
energy would be achieved by replacing suction piping & limiting
suction velocity lower than 1.80 m/sec
6.4 Suction pit modelling
The suction pits constructed at all the pumping stations are of the
same size. At present no vortices are visible & as evident from PS-1,
where pumps of highest discharge (2.018 cumecs) are being
operated smoothly without any sign of cavitation.
The proposed increase in discharge by nearly 24-25% may need
some modification as per individual pump manufacturer’s
requirement. It is proposed to make it mandatory for the successful
bidder to get hydraulic modeling of sump pit for enhanced flow
requirements for each pump of ph.1 to be replaced. The bidder
would be directed to include cost of any modification required in
sump pit arrangement s in the cost of pumps itself. Alternatively, it
is proposed to knock off the RCC wall above canal bed level and
remove the gates altogether. This would smoothen the flow of water
into the sump uniformly and at much lower velocity. A separate
note on sump sizing is enclosed (Annesure A).
According to the ANSI 9.8, ANSI permits suction bell entrance velocity of 1.7 m/sec, which means the dia 1.5m of existing bell is
adequate for proposed pumps. The ANSI recommendations are mainly based on bell diameter D which remains same. The ANSI recommendations for circular CAN arrangement suggest similar
arrangement as for existing sumps.
6.5 Replacement of Motors
All the Ph-I motors are proposed to be replaced due to higher power
input requirement and different RPM requirement of pumps to be
replaced.
However, in case of Ph-II pumps to be replaced, the power input
requirement is likely to be same or less and as such only pumps are
proposed to be replaced. The history sheet of repairs of these
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 21
motors is not available but no substantial gain in energy efficiency
is expected by replacement of these motors.
6.6 Replacement of transformers
As per performance tests conducted on each of 18 nos.
transformers (draft report placed at Annexure-5), these
transformers can be continued to be used by repair & rehabilitation
of these transformers, which would be included in the estimates.
Only, where capacity of transformer is required to be increased,
proposals for new transformers would be included in the package.
Further, it is proposed to install breakers for the transformers, as
per the mandatory requirement under electricity rules. The existing
transformers are OLTC type but their control panels are not
installed. These are now proposed to be installed.
6.7 Replacement of valves and appurtenances at PS
The department has carried out and proposes to replace some
NRV’s sluice valves and other appurtenances. The provision for
repair/rehabilitation & replacement of remaining appurtenances in
pumping station would be proposed as per condition assessment
for each equipment.
6.8 Replacement of electrical control equipments
It is proposed to provide soft starters to facilitate smooth starting of
motors. Similarly Cables, APFC panels & other electrical
accessories would be provided to achieve sustained energy saving.
6.9 Flow Meters :
For PS-1,2,3&4 flow meters are proposed to be installed on
individual pump delivery and for the remaining pumping stations,
flow meters shall be installed on the two parallel rising mains. It is
also proposed to provide flow meter at IGMC outlet, and at tail of
RGLC as well as at each en-route drawal point on the entire canal
to measure and monitor the consumptions and the canal losses.
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 22
6.10 Pressure Sensors & Transmitters and Level Sensors &
Transmitters
It is proposed to install pressure sensors and transmitters on
suction and delivery of each pump for real time monitoring of
operational efficiency of the pumps. It is also proposed to
install two level sensors and transmitters in the forebay of
each pumping station, one before the trash rack and one
before the suction pit
6.11 Instrument Control Panel
All the existing instrument control panels are out of order and
therefore proposed to be replaced under the proposed
contract.
6.12 PLC and SCADA
Under this contract, it is proposed to install RTU/PLC with 43
cm touch screen HMI at each of the pumping station and
SCADA with server etc at PS-5 to monitor and control in real
time for fail safe efficient operations. The RGLC SCADA shall
be connected to Jodhpur’s Master Control Centre.
6.13 Pump house campus and civil Structures
The requisite repair and rehabilitation of pump house civil
structure, campus development, approach road, street lighting,
drainage etc. would be provided under the package.
7. DBOM CONTRACTS
7.1 DBOM contracts for all 8 pumping stations & pipe lines
It is proposed to invite DBOM contract for carrying out capital
works for Pumping stations & pipelines with the objective of
maintaining it for 10 years after commissioning & with guaranteed
energy consumption. The evaluation of bids would be done by
loading capitalized cost of difference of extra energy consumption
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 23
quoted over lowest energy consumption is capital cost of each
bidder.
The bidder shall be given incentive if the energy consumption is
less than guaranteed energy consumption, but would be charged
penalty if the energy consumption exceeds the guaranteed energy
consumption along with recovery of extra energy bill.
It is also proposed to Bench mark energy consumption at the
inception of DBOM contract to assess overall energy saved for
which energy audit at the inception stage will have to be carried
out by the successful bidder.
7.2 Annual contracts for Patrolling, Desilting, Deweeding repair
and rehabilitation of canal and service road
The capital costs to rehabilitate canal/service road is not included
in the feasibility report of the project which contains provision for
raising of escapes & outlets, aqueducts for enhanced flow.
The embankments of canal are damaged due to rain cuts, erosion
and side slopes in cutting section have also damaged & at many
places inspection banks have been completely blocked/ damaged
and are non pliable by inspection vehicles. At many places the
sliding soil mass in cutting sections is getting entry into the canal
thereby not only increasing silt load but also increasing weed
growth & turbidity in canal water.
The continued deterioration in condition of canal is contributing to
incidences of weeds growth and heading up of canal thereby
increasing seepage & evaporation losses.
It is of utmost importance to keep the canal in good shape by
regularly attending to repair & rehabilitation works inside the
canal during closure period and outside the canal throughout the
year. Regular patrolling on canal inspection bank is required for
which not only inspection bank but service road is also required to
be kept in proper condition.
Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of
pumping machinery of RGLC system
Seureca(JV)STC Page 24
It is difficult to envisage all the works of rehabilitation over a
period of 10 years in one stage. These works are required to be
assessed every year and attended to during canal enclosure period.
It is therefore proposed that maintenance of canal portion of the
RGLC should be kept outside the DBOM contract & should
preferably be undertaken through single or multiple contracts in
different reaches.
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