design concept report of rehab-replacment of p.m. of rglc (2)

Jodhpur Urban WS Reorganisation Project Design concept report for rehab/replacement of

pumping machinery of RGLC system

Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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.



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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.



Seureca(JV)STC

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



Seureca(JV)STC

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



Seureca(JV)STC

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.



Seureca(JV)STC

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



Seureca(JV)STC

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.



Seureca(JV)STC

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.