WATER
SUPPLY SERVICE LEVEL AND 24X7 EXPECTATIONS
A. Service level and 24x7
concepts
Water
supply service level has been defined for urban and rural areas in the CPHEEO
Manual.
|
Sr. No.
|
Service level
area
|
Range
|
LPCD
|
Type of area
|
Minimum Pressure
in m
|
|
1
|
Urban
|
Up to population
1000000
|
70
|
Single floor
Housing
|
7
|
|
2
|
Urban
|
Up to population
1000000
|
70
|
Double floor
Housing
|
12
|
|
3
|
Urban
|
Up to population
1000000
|
70
|
Triple floor
Housing
|
17
|
|
4
|
Urban
|
More than 1000000
population
|
135
|
Single floor
Housing
|
7
|
|
5
|
Urban
|
More than 1000000
population
|
135
|
Double floor
Housing
|
12
|
|
6
|
Urban
|
More than 1000000
population
|
135
|
Triple floor
Housing
|
17
|
|
7
|
Urban
|
Up to population
1000000 with sewerage scheme contemplated
|
135
|
Single floor
Housing
|
7
|
|
8
|
Urban
|
Up to population
1000000 with sewerage scheme contemplated
|
135
|
Double floor
Housing
|
12
|
|
9
|
Urban
|
Up to population
1000000 with sewerage scheme contemplated
|
135
|
Triple floor
Housing
|
17
|
|
10
|
Urban
|
More than 1000000
population with sewerage scheme contemplated
|
150
|
Single floor
Housing
|
7
|
|
11
|
Urban
|
More than 1000000
population with sewerage scheme contemplated
|
150
|
Double floor
Housing
|
12
|
|
12
|
Urban
|
More than 1000000
population with sewerage scheme contemplated
|
150
|
Triple floor
Housing
|
17
|
|
13
|
Rural
|
Stand post
|
40
|
……………..
|
3
|
|
14
|
Rural
|
House
connections,
|
40
|
Single floor
|
7
|
|
15
|
Rural
|
House connection,
|
55
|
Single floor
|
7
|
|
16
|
Rural
|
House connection
|
70
|
Single floor
|
7
|
In
the above statement the population figures are the projected design
populations. In such cases most of the urban areas are covered under the remark
of “Sewerage scheme is contemplated.”
B. Considering the cases for
24x7 level supplies
1.
Case
I
In
case of urban areas with 70 LPCD water supply for 24x7 supplies, days water
supply for the household with 5 persons per house works out to 350 Lit/day.
If
the supply is 24 hours then average hourly supply is 350/24 = 14.6 lit/hr.
If
the supply is 24 hours then average supply per minute = 14.6/60 = 0.24 lit/min.
Considering
peak factor of 3 for this area this supply in peak hours will be = 0.24*3 =
0.72 lit/min.
Even
during peak hours the one bucket of 15 Lit capacity will be filled with water
in 15/0.72 = 20 min.
2.
Case
II
In
case of urban areas with 135 LPCD water supply for 24x7 supplies, days water
supply for the household with 5 persons per house works out to 675 Lit/day.
If
the supply is 24 hours then average hourly supply is 675/24 = 28.12 lit/hr.
If
the supply is 24 hours then average supply per minute = 28.12/60 = 0.46
lit/min.
Considering
peak factor of 3 for this area this supply in peak hours will be = 0.46*3 =
1.38 lit/min.
Even
during peak hours the one bucket of 15 Lit capacity will be filled with water in
15/1.38 = 10.86 min.
3.
Case
III
In
case of urban areas with 150 LPCD water supply for 24x7 supplies, days water
supply for the household with 5 persons per house works out to 750 Lit/day.
If
the supply is 24 hours then average hourly supply is 750/24 = 31.25 lit/hr.
If
the supply is 24 hours then average supply per minute = 28.12/60 = 0.52
lit/min.
Considering
peak factor of 3 for this area this supply in peak hours will be = 0.46*3 =
1.56 lit/min.
Even
during peak hours the one bucket of 15 Lit capacity will be filled with water
in 15/1.56 = 9.61 min.
4.
Case
IV
In
case of Rural areas with 40 LPCD water supply for 24x7 supplies, days water
supply for the household with 7 persons per house works out to 280 Lit/day.
If
the supply is 24 hours then average hourly supply is 280/24 = 11.70 lit/hr.
If
the supply is 24 hours then average supply per minute = 11.70/60 = 0.19
lit/min.
Considering
peak factor of 3 for this area this supply in peak hours will be = 0.19*3 =
0.57 lit/min.
Even
during peak hours the one bucket of 15 Lit capacity will be filled with water
in 15/0.57 = 26.32 min.
5.
Case
V
In
case of urban areas with 55 LPCD water supply for 24x7 supplies, days water
supply for the household with 7 persons per house works out to 385 Lit/day.
If
the supply is 24 hours then average hourly supply is 385/24 = 16.1 lit/hr.
If
the supply is 24 hours then average supply per minute = 16.1/60 = 0.27 lit/min.
Considering
peak factor of 3 for this area this supply in peak hours will be = 0.27*3 = 0.51
lit/min.
Even
during peak hours the one bucket of 15 Lit capacity will be filled with water
in 15/0.51 = 29.41 min.
1.
Case
III
In
case of urban areas with 70 LPCD water supply for 24x7 supplies, days water
supply for the household with 7 persons per house works out to 490 Lit/day.
If
the supply is 24 hours then average hourly supply is 490/24 = 20.41 lit/hr.
If
the supply is 24 hours then average supply per minute = 20.41/60 = 0.34
lit/min.
Considering
peak factor of 3 for this area this supply in peak hours will be = 0.34*3 = 1.02
lit/min.
Even
during peak hours the one bucket of 15 Lit capacity will be filled with water
in 15/1.02 = 14.71 min.
C. Checking the pressure
criteria
Lowest
pressure criteria at the consumer end are 7 m. It can be assumed that the
losses in the house connection and meter assembly are 1.5 m. And assuming the
connection is at higher level as compared to the road level. Also presuming the
effective head remaining at the consumer tap is about 3 m.
Assume
connection size as 15 mm OD and 12 mm ID. Corresponding area is 0.000113 sq.m.
Hence with pressure of 3 m on the tap velocity will work out to V=
(2*9.81*3)^0.5 =7.67 m/sec.
Flow
= 0.000113*7.67=0.000867 cum/sec =0.86 lit/sec = 52 lit/min.
Thus
even for the lowest pressure flow is much more than the 24x7 flow requirements.
The
bucket of 15 lit capacities will be filled in 17 sec.
Whole
requirement 750 lit/day will be fulfilled in less than 15 min., if the pressure
is maintained.
In
case of other pressures for double story and triple story viz. 12 m and 17 m, similar
calculations will show that if the pressure is maintained the systems will be
more satisfactory systems.
D. Consumer level of
satisfaction
Consumer
can be happy if he gets the water in required quantity as per norms reliably
every day, at satisfactory pressures.
When
a one bucket is getting filled consumer needs to wait.
Once
the bucket is filled in he can take out that bucket and put the next bucket
under the tap.
Consumer
goes with filled bucket and empties it in the storage and gets back to the tap.
If
he sees that the next bucket is filled, he is happy as he is not required to
wait.
If
the time lag for the consumer to come back and see the bucket is full is 1.5
min., then the 15 lit bucket is filled in 1.5 min., hence, the rate of flow is
minimum 10 lit/min.
Following
table gives the flow of water from the 12 mm dia. tap at various velocities and
corresponding pressure range.
|
Dia.
in mm
|
Dia.
in m D
|
Area
in sq. mm
|
Velocity
in m/sec
|
Flow
in cum/sec
|
Flow
in Lit/min.
|
V*V
|
(V*V/2g)=
h in m
|
|
12
|
0.012
|
0.000113
|
0.1
|
0.01130
|
0.6782
|
0.01
|
0.0005
|
|
12
|
0.012
|
0.000113
|
0.2
|
0.02261
|
1.3565
|
0.04
|
0.0020
|
|
12
|
0.012
|
0.000113
|
0.3
|
0.03391
|
2.0347
|
0.09
|
0.0046
|
|
12
|
0.012
|
0.000113
|
0.4
|
0.04522
|
2.7130
|
0.16
|
0.0082
|
|
12
|
0.012
|
0.000113
|
0.5
|
0.05652
|
3.3912
|
0.25
|
0.0127
|
|
12
|
0.012
|
0.000113
|
0.6
|
0.06782
|
4.0694
|
0.36
|
0.0183
|
|
12
|
0.012
|
0.000113
|
0.7
|
0.07913
|
4.7477
|
0.49
|
0.0250
|
|
12
|
0.012
|
0.000113
|
0.8
|
0.09043
|
5.4259
|
0.64
|
0.0326
|
|
12
|
0.012
|
0.000113
|
0.9
|
0.10174
|
6.1042
|
0.81
|
0.0413
|
|
12
|
0.012
|
0.000113
|
1
|
0.11304
|
6.7824
|
1
|
0.0510
|
|
12
|
0.012
|
0.000113
|
1.1
|
0.12434
|
7.4606
|
1.21
|
0.0617
|
|
12
|
0.012
|
0.000113
|
1.2
|
0.13565
|
8.1389
|
1.44
|
0.0734
|
|
12
|
0.012
|
0.000113
|
1.3
|
0.14695
|
8.8171
|
1.69
|
0.0861
|
|
12
|
0.012
|
0.000113
|
1.4
|
0.15826
|
9.4954
|
1.96
|
0.0999
|
|
12
|
0.012
|
0.000113
|
1.5
|
0.16956
|
10.1736
|
2.25
|
0.1147
|
|
12
|
0.012
|
0.000113
|
1.6
|
0.18086
|
10.8518
|
2.56
|
0.1305
|
|
12
|
0.012
|
0.000113
|
1.7
|
0.19217
|
11.5301
|
2.89
|
0.1473
|
|
12
|
0.012
|
0.000113
|
1.8
|
0.20347
|
12.2083
|
3.24
|
0.1651
|
|
12
|
0.012
|
0.000113
|
1.9
|
0.21478
|
12.8866
|
3.61
|
0.1840
|
|
12
|
0.012
|
0.000113
|
2
|
0.22608
|
13.5648
|
4
|
0.2039
|
|
12
|
0.012
|
0.000113
|
2.1
|
0.23738
|
14.2430
|
4.41
|
0.2248
|
|
12
|
0.012
|
0.000113
|
2.2
|
0.24869
|
14.9213
|
4.84
|
0.2467
|
Hence,
as for as the flow is concerned the level of satisfaction for the consumer is
10 lit per min. corresponding duration expected by the consumer to complete the
total water supply in a day will be 75 min or 1 hour 15 min.
In
case of urban and rural areas if the pressures are maintained in such a way
that he 15 lit bucket will be filled in 1.5 min. then required water supply
will be given in durations as mentioned in the following table,
|
Area
|
House
hold size
|
LPCD
|
Demand
in lit/day
|
Supply
in lit/min.
|
Requirement
of supply in min./day
|
Requirement
of supply in hours /day
|
|
Urban
|
5
|
70
|
350
|
10
|
35
|
0.58
|
|
Urban
|
5
|
135
|
675
|
10
|
68
|
1.13
|
|
Urban
|
5
|
150
|
750
|
10
|
75
|
1.25
|
|
Rural
|
7
|
40
|
280
|
10
|
28
|
0.47
|
|
Rural
|
7
|
55
|
385
|
10
|
39
|
0.64
|
|
Rural
|
7
|
70
|
490
|
10
|
49
|
0.82
|
|
Rural
|
7
|
100
|
700
|
10
|
70
|
1.17
|
Thus
in both the cases of Urban and rural areas requirement of water can be
fulfilled in less than 1.5 hours considering all sorts of cases, provided
pressures are maintained in such a way that the supply can be ensured at 10 lit
per min.
Then
why there is an insistence on 24x7 water supply. It does mean that consumer
can, at his will utilize the services of water supply at any 0.58 hours to 1.17
hour duration to meet out his demand. He expects that the system shall run
24x7, and supply 24x7.
Thus
it can be seen that 24x7 can have different interpretation.
E. Interpret 24x7
24x7
water supplies has following shaded areas,
·
Water
supplied is not directly addressed to demand of the consumer. There can be
intermediate storage, either in the form of small tanks in the ground level or
in the form of small tank on the top floors. These introduce the discontinuity
with the supply and demand. Hence, demand pattern does not co-relate with
supply. Naturally the demand peaks are subsided in the storages and the
consumer is happy, if the supply is available to him even through the local
storage. Peak factors are not transferred to the supply levels but they are
balanced in the interim storages, but there are bulk stretches to have the
local storages filled in.
·
In
case of low cost housing areas and the slums the demand is directly stretched
to the supplies for the ESR.
·
Consumer
demand is not continuous with fluctuating rates, in 24 hours. Hence, the multiplications
of demands, with the population are not a reality.
·
It
is not the flow or pressure, but the most important is the reliability of
service level at any time is the requirement.
·
Distribution
system is the tool and the system is more important to impart the reliability.
Hence,
it is to emphasize that the reliability of the system up to ESR, where, there
is a hydraulic discontinuity, shall be most reliable system and shall have the
potential to work for 24 hours, from where the distribution can draw the
required water by consumer at any time of the day.
This
is called 24x7 supplies.
F. Requirements for the 24x7
supplies
·
Sufficient
overall storages, say up to 33% to 40%.
·
Every
storage/ESR shall have the influence area and it is proportional to the height
of ESR.
·
Every
ESR shall have identified DMA and inter DMA connections shall be prohibited.
·
Every
ESR shall have the influence population within the DMA and demand can be worked
out by knowing the population density.
·
All
ESRs shall be having system of multi-outlets, so as to ensure the each sub DMA
shall be having a maximum population of 15000 souls.
·
Each
ESR shall have an influence zone of 1.5 to 2.0 sq.km area
·
Stretching
the lines beyond influence zones will not be feasible.
·
Distribution
system outlets shall be controlled and in any case the maximum 5 threads near
ESR need to be opened.
·
It
is the pressure that is important in the distribution system and flow will be
available whenever required.
·
In
any case the ESR water level shall not go below LSL.
·
Overflows
shall have controls.
·
Distribution
pressure optimization can be done by use PRVs or master pieces.
·
It
will need more water for 24x7 initially and it shall be financially controlled
when the consumer reacts to the bill. Till then the overconsumption shall be
sustained. Hence, it is better to think 24x7 from part areas and not for full
city.
·
24x7
will be eased out with meterization, but not 100% obligatory. It mainly depends
on the billing system.
Then
it is 24x7.
G. Water supply status at
consumer level
Cities
trying for the 24x7, need to have the pre24x7 status conducive to the
conversion. However, some cities are in such a stage that, they may be facing
the problem of depressurization of the system along with intermittence in
supply. City administration considers that the increase in supply, by operating
the lines every alternate day will solve the problem. However, this does not
help. Consumers try to get maximum supply from the pipe lines either by getting
the supply in pits or they go further to use pumping direct to the pipe line
during the supply hours. Even with supplying large quantity on the supply day
consumer need to pump the water because of depressurization. Pressure gets
reduced as each consumer is pumping directly from the line, in which the pipe
line acts as a sump and while pumping, suction is created in the line using the
positive pressure of the pipe line. Using such a system by number of consumers
the system pressures go down rapidly.
It
is interesting to point out a case study in Pune City. Some observations were taken in the
Vimannagar area, for the supply status. Sample meters were fixed on the
consumer lines. Readings were taken for 15 days, in the supply hours. Quality
of meter was very good. All the meters registered more than 350 LPCD water in
duration of about 70 to 80 minutes of supply. Those consumers who did not use
pumps had to worry about the supply. All others who afforded pumping had to go
in for pumping to get the supply. As per hydraulic model this area was under
less pressure as it is on the higher elevation and at farther end from the Elevated
service reservoir.
Again
assuming the consumer connection diameter of 15 mm. 350 LPCD in 80 minutes
means 4.35 lit per min. And for a family actual flow was 4.35 * 5 = 21.75 lit
per minute. This is definitely much more than the level of satisfaction.
Naturally the consumers did not have any complaint.
Now,
if such a supply is to be turned into 24x7, what is expected to be done?
Consumers have already contributed for their level of satisfaction.
To
change the service level to the level of satisfaction without using pumping
practices is very difficult. Improvement of pressure in the system can be done
by adding one common pumping station to boost the pressures in the system.
Alternatively this can be done by adding one ESR nearer to this area. However,
does not get convinced that he will get the supply with pressures. He may not
have the patience to wait for 24 hour supply, as he is habituated to get the
supply in 70 to 80 minutes. Pressures identified in the 24x7 supply system can
be definitely less than the pressures he has been addicted to.
In
such circumstances changing of consumer behavior is very difficult. Problem
relates to consumer behavior and not setting of 24x7 supplies.
There
is similar situation when the consumers prefer to go into pits for the benefit
of the water supply in preference to the neighboring consumer. If we go along
the line we find that the depth of the pit is increasing on upstream side. In
such case, any improvement done in the pressures of the system will not be
effective. Consumers will continue to get the water in the pits only. Only
expected change can be that the consumer may have steps in the pit-taps, so
that they can get the water at the higher level, instead of utensils getting
drowned in the flown water. Out of fear consumer continues to get water in the
pits. The phenomenon can be observed in the seasonal changes in the supply. In
rainy season people get water at higher level, and consumer feels that he can
get rid of some lift for lifting the bucket to above G.L.
In
such cases the remedy is to dispense with pipe line as existing and lay the new
line. Old pipe line might be having the holes from the bottom of the pipe line.
They are not desirable nor they be easily plugged permanently. Once the new
line is laid supply for the old line can be disconnected and the connections
can be given from the new line. This being the improvement work in the system
it shall be done with expenses borne by the scheme.
While
changing the system by new lines another criterion is to lay pipe lines on both
sides of the road, in the city. It is expected that the 100 mm line can
contribute to 72 house connections of 15 mm dia. and it will give the
satisfactory flows, if the pressures are maintained. For safety and for future
expansion in the first stage it can be considered to have 50 No. of 15 mm dia.
equivalent connections on one 100 mm line.
It
is also necessary to decide the consumer line diameter for giving house
connections and all the connections shall be restricted to be given on that
diameter only. All above diameters pipe lines can be system lines.
H. Deciding the consumer line
diameter
Size
of consumer line is dependent on the population of the city. It will calculate
the no. of households. In the present stage there can be some percentage of
households accommodated in the storied buildings. For calculating the
population in storied buildings/apartments, a nominal survey of the group of
consumers getting supply in the sumps in their premises and then pumping to the
top level storages, needs to be done. A trend is needs to be anticipated for
the future.
Secondly,
if the city distribution is designed with 12 m or 17 m pressures, it can be
assumed that the buildings upto two stories can be easily dealt with direct
pressure. These decisions can be taken in the DMA wise also, for a bigger city.
Consumer diameter can be different in the different DMAs.
In
Maharashtra there are 26 Municipal Corporations and 221 Municipal Councils. For
Corporations there can be separate detailed design for the distribution system.
But as far as the Municipal Councils are concerned following analysis will help
for the guidance.
Configuration
of the Municipal councils is as following,
|
Sr.
No.
|
No. of Municipal
councils
|
Population range
in 2011
|
Max. HH in 2011
|
|
1
|
23
|
Up to 15000
|
3000
|
|
2
|
16
|
15000 to 20000
|
4000
|
|
3
|
26
|
20000 to 25000
|
5000
|
|
4
|
24
|
25000 to 30000
|
6000
|
|
5
|
21
|
30000 to 35000
|
7000
|
|
6
|
22
|
35000 to 40000
|
8000
|
|
7
|
13
|
40000 to 45000
|
9000
|
|
8
|
13
|
45000 to 50000
|
10000
|
|
9
|
16
|
50000 to 60000
|
12000
|
|
10
|
11
|
60000 to70000
|
14000
|
|
11
|
12
|
70000 to 90000
|
18000
|
|
12
|
7
|
90000 to 100000
|
20000
|
|
13
|
11
|
100000 to 150000
|
30000
|
|
14
|
6
|
150000 to 300000
|
60000
|
|
|
221
|
|
|
All
these councils are expected to increase in their population by about 20% per
decade. In Design stage of 30 years the population can be increased to
1.2*1.2*1.2 = 1.728 times the present range of population. Assuming also the
household size will be 5 up to design stage. Further the target water supply
shall be 750 lit per household and there can be about 25% losses in the
distribution system. Hence, up to ESR household supply level will reach to
750*1.25 = 937.5 Lit per day.
Approximate
design requirements of storages proposed in the Municipal Councils
|
Max. HH in 2011
|
Design HH in 2041
|
Demand at ESR
|
ESR cap. Required
in ML
|
Cap. of each ESR
in ML
|
No. of ESRs
|
Total Elevated
storage in ML
|
|
3000
|
5184
|
4.86
|
1.62
|
0.50
|
3.00
|
1.50
|
|
4000
|
6912
|
6.48
|
2.16
|
0.75
|
3.00
|
2.25
|
|
5000
|
8640
|
8.10
|
2.70
|
1.00
|
3.00
|
3.00
|
|
6000
|
10368
|
9.72
|
3.24
|
1.00
|
4.00
|
4.00
|
|
7000
|
12096
|
11.34
|
3.78
|
1.00
|
4.00
|
4.00
|
|
8000
|
13824
|
12.96
|
4.32
|
1.00
|
4.00
|
4.00
|
|
9000
|
15552
|
14.58
|
4.86
|
1.50
|
3.00
|
4.50
|
|
10000
|
17280
|
16.20
|
5.40
|
1.50
|
4.00
|
6.00
|
|
12000
|
20736
|
19.44
|
6.48
|
1.50
|
4.00
|
6.00
|
|
14000
|
24192
|
22.68
|
7.56
|
2.00
|
4.00
|
8.00
|
|
18000
|
31104
|
29.16
|
9.72
|
2.00
|
5.00
|
10.00
|
|
20000
|
34560
|
32.40
|
10.80
|
2.50
|
4.00
|
10.00
|
|
30000
|
51840
|
48.60
|
16.20
|
2.50
|
6.00
|
15.00
|
|
60000
|
103680
|
97.20
|
32.40
|
2.50
|
13.00
|
32.50
|
Using
multi-outlet system to the proposed ESRs we can calculate the configuration of
outlets having distribution velocity as 1 m/sec. Outlet diameter can be given
from the following table in which diameter of pipe and its carrying capacity in
LPS is given with assumed velocity 1 m/sec.
|
Dia. of pipe in
mm
|
Velocity in
m/sec.
|
Carrying capacity
of pipe in LPS
|
|
80
|
1 m/sec
|
5.0
|
|
100
|
1 m/sec
|
7.8
|
|
150
|
1 m/sec
|
17.6
|
|
200
|
1 m/sec
|
31.3
|
|
250
|
1 m/sec
|
48.8
|
|
300
|
1 m/sec
|
70.3
|
|
350
|
1 m/sec
|
95.7
|
|
400
|
1 m/sec
|
125.0
|
|
450
|
1 m/sec
|
158.2
|
|
500
|
1 m/sec
|
195.3
|
Guiding
table for the ESR outlet diameters in mm and selection of Diameter of pipe in
distribution system on which connection can be given
|
Max. HH in 2011
|
Design HH in 2041
|
No. of ESRs
|
HH per
ESR
|
No. of outlets
|
Flow in LPS
through each outlet
|
Dia. of Each
outlet or stem dia. in mm
|
Max. dia. on
which connections can be given in mm
|
|
3000
|
5184
|
3.00
|
1728.00
|
2.00
|
22.50
|
150.00
|
100
|
|
4000
|
6912
|
3.00
|
2304.00
|
2.00
|
30.00
|
150.00
|
100
|
|
5000
|
8640
|
3.00
|
2880.00
|
2.00
|
37.50
|
200.00
|
100
|
|
6000
|
10368
|
4.00
|
2592.00
|
2.00
|
33.75
|
200.00
|
100
|
|
7000
|
12096
|
4.00
|
3024.00
|
3.00
|
26.25
|
150.00
|
100
|
|
8000
|
13824
|
4.00
|
3456.00
|
3.00
|
30.00
|
150.00
|
100
|
|
9000
|
15552
|
3.00
|
5184.00
|
2.00
|
67.50
|
250.00
|
100
|
|
10000
|
17280
|
4.00
|
4320.00
|
2.00
|
56.25
|
250.00
|
100
|
|
12000
|
20736
|
4.00
|
5184.00
|
2.00
|
67.50
|
250.00
|
100
|
|
14000
|
24192
|
4.00
|
6048.00
|
2.00
|
78.75
|
300.00
|
100
|
|
18000
|
31104
|
5.00
|
6220.80
|
2.00
|
81.00
|
300.00
|
100
|
|
20000
|
34560
|
4.00
|
8640.00
|
3.00
|
75.00
|
300.00
|
100
|
|
30000
|
51840
|
6.00
|
8640.00
|
3.00
|
75.00
|
300.00
|
100
|
|
60000
|
103680
|
13.00
|
7975.38
|
3.00
|
69.23
|
250.00
|
100
|
Considering
the future developments it can be better practice to have consumer service
lines shall be on both sides of the roads at least in cities having population
more than 30000 as per 2011 census population.
Similar
calculation can be made for the various Corporations. It can be found that the
consumer service line diameter can increase to 150 mm.
All
the consumer service lines need not be designed. However, they shall be laid in
addition to the design lines to be laid on the same road. It shall be ensured
that the pressures at any point at the end of service line shall be design
pressure.
In
big cities it is not necessary to design distribution with more than minimum
pressure of 7 m, as practically all the properties can be having the sump and
pump house. This can allow about 18 m pressure loss in the distribution system,
from ESR to Consumer service line. Pressure optimization can be done by PRVs.
