10
CHAPTER 1I
WATER SUPPLY SCHEMES UNDER PULAU LANGKAWI
2.1
Existing Water Supply Schemes
2.1.1
General
Presently the main sources of raw water on the island are the Malut
impounding reservoir, the Sungai. Melaka , Sungai Saga and Sungai Kemboja. Two
bunded storage reservoirs has been constructed at Padang saga and Padang Mat Sirat
which are presently maintained as a reserve source of raw water which has been
abstracted from Sungai Melaka and Sungai Saga. An additional surface source has
been obtained from Telaga Tujuh to discharge into Malut reservoir and also flow
direct into Padang Saga Phase III Treatment plant.
A treatment works designed to provide an output of 54.6 Million Liter per
Day (MLD) that is about 12 Million Gallon per day (MGD) was constructed near the
coastline of the mainland at Sungai Baru, Kuala Perlis. The raw water for this
scheme is to be abstracted from the Arau canal, which is one of the major arteries of
the existing irrigation of Muda Agricultural Development Authority (MADA). The
network is fed from the large Muda, Pedu and Ahning reservoirs in forest reserve
areas well inland of North Kedah with total capacity of about 332,000 million
gallons. The new Beris dam under construction will also be fully operational in next
few years will supplement the tasks of the existing three reservoirs under the
management of MADA.
11
2.1.2
Raw Water Sources
Malut Dam
The Malut dam with its impounded reservoir is the single most important
source of raw water on Langkawi island at present. It is used to store excess water in
the wet season and to augment supply in the dry season when there is little or no flow
at the river intake sites.
here are four intake penstocks on the draw off tower, at levels 73.0m, 66.6m,
60.2m and 53.8m Outside Diameter (OD). The scour is at 47.0m OD whilst the
overflow spillway is at 76.0 OD. The usable volume of water above the 53.8 OD
intake level is approximately 4000 Million Liter or about the equivalent of about 1.5
years average runoff from the 3.4 Sq. Km.
At present water from the Malut reservoir is supplied during the dry season to
the Padang Saga Phase III treatment plant and, if necessary, to the Kampong
Kemboja Treatment Plant as well through a 600mm diameter ductile iron gravity
pipeline. It is also used to water greens and fairways at the Langkawi Golf Club via a
sprinkler system.
Samples taken from the Malut dam show that the water is very high in iron
and manganese contents. Water quality below 66.6 m OD is poor. As such the need
to limit draw off to storage above the first and second intake levels for quality
reasons.
Sungai Saga Intake and Padang Saga Bunded Storage
A weir has been constructed by the Jabatan Parit dan Saliran (JPS) across
the Sungai Saga to form an intake pond for irrigation water abstraction. Intake sump
has been constructed along side the above pond and during the wet season, a low lift
12
submersible pump delivers water to the Padang Saga Phase II Treatment Plant. A
Bunded Storage reservoir has been constructed along side the Padang Saga River
and the excess water from the river is stored, to be made available as an emergency
reserve to the Padang saga treatment plant. When the Sungai. Saga dries up the JPS
required a cessation in abstraction from the river.
The Bunded Storage at Sungai Padang saga has a capacity of 300 Million
with an overflow Top Water Lavel (TWL) of 26.2m OD and a Bottom Water Level
(BWL) of 21.0 m OD. A 600mm diameter gravity main has been laid connecting the
Telaga Tujuh Weir intake and the Bunded storage reservoir to augment supply water
if necessary.
Sungai Melaka Intake and Padang Matsirat Bunded Storage
The intake has been constructed behind a JPS gated barrage weir across the
Sungai Melaka. The yield from Sungai Melaka River can reach to a maximum of 18
MLD during wet season and drops below 9 Mld during the dry season.
A Bunded storage has been constructed along side the Sg. Melaka Intake at
Padang Matsirat. Submersible pumps have been installed which are made to operate
to fill the bunded reservoir.The excess water from the reservoir is pumped to the
Malut reservoir to be used during dry season.
The Telaga Tujuh Intake
Telaga Tujuh forms an important source of raw water and provides additional
security and flexibility to the water supply system. A concrete weir built at a level
158.5m OD across the upper rock face a waterfall forms the intake for a 600mm
diameter falling main. The pipeline discharge into the Padang saga Bunded Sorage
reservoir via two energy dissipation wells and control valves. Water is allowed to
13
flow into the Malut reservoir and Padang saga Phase III treatment plant . The valves
at Kg. Nyior Cabang Junction operated intermittently to discharge water into Malut
Reservoir and Padang Saga Phase III Treatment Plant.
Sungai Kemoja Intake
The Sg. Kemboja intake is situated at upstream river where JPS has
constructed a barrage. The intake has four submersible pumps (2 operational and 2
standby ) with the capacity of 10 MLD and deliver raw water to the Kampong.
Kemboja Treatment plant. During wet season the water abstracted from the intake is
sufficient and the plant will not be dependent on Malut Reservoir.
Sungai Baru Intake
The intake is located near Simpang Empat town just upstream of the second
tidal gate at the Arau irrigation canal. It is understood that Arau canal would have a
capacity to accommodate up to 540mgd of flow. The water mainly come from the
existing Muda, Pedu and Ahning reservoirs, a number of rivers joining upstream and
rainfall. The sophisticated irrigation scheme under MADA would allow for efficient
redirection and control of water flow to the canal to meet the requirement at all times
of the season.
2.1.3
Treatment Plants
Padang Saga Treatment Plant
Padang Saga Treatment Plant has been built at different times in three phases.
The Pahase I plant has the capacity of 2.3 MLD , Phase II has a capacity of 5.4 MLD
14
and Phase III has the capacity of 128 MLD. Each phase of the treatment plant has its
own and independent treatment system. The treatment system comprises of circular
cascade aerator with mixing flume, flocculation and lovo flow sedimentation tanks,
pressure filters, clear water tank and high lift pumps.
The water treated from Padang Saga treatment plant has been pumped up to
the 0.45ML reservoir and 13.6 ML reservoirs both located on the adjacent hill of the
padang saga Treatment plant. From these two reservoirs water gravitate to 13.6 ML
Padang Lalang reservoir to the north and 4.5ML reservoir in Bukit dendang near
Kuah town.
Kampong Kemboja Treatment Plant
Kampong Kemboja Treatment Plant has two phases of treatment works. The
phase I has the capacity to deliver 3.2 MLD, Whereas the Phase II has the capacity
5.4 MLD. The treated water is pumped via 300mm diameter pipe to Bukit
Changkuan reservoir.
The treatment process for each phase comprise of a circular cascade aerator,
chemical reaction tanks, clarifiers, rapid sand filters, back washing tank and clear
water tanks.
Sungai Bahru Treatment Plant ( mainland)
The treatment works is located near the coastline at Sungai Bahru and about
3.3 KM from the intake. The works is designed to provide an output of 54.6 MLD
(12mgd) of treated water. An allowance of 5% of output has been made to cater for
works usage of water for backwashing, chemical dosing, etc. and hence the
throughout is 57.2 MLD (12.6mgd).
15
The basic units/facilities provided for the plant are inlet chamber, aerator and
mixing chamber, flocculation and “Lovo” type sedimentation tanks. rapid gravity
filters, contact balance and clear water tanks, treated water pump station, chemical
handling, storage mixing and dosing facilities.
A 711mm OD steel submarine pipeline has been laid across the Malacca Straits
from treatment works to channel the water to the terminal storage tank at Penarak,
Pulau Langkawi.
2.1.4
Reservoirs
The distribution of water supply on Langkawi island originates from the
Padang Saga Reservoir and Bukit Changkuan Reservoir. Padang Saga are fed by the
Padang Saga Treatment Plants and Penarak Booster Satation (which obtained the
supply from Sungai Baru Treatment Plant in Perlis). Whilst Bukit Changkuan
Reservoir is fed by the Kemboja treatment works. Recent cross connection has
enabled the Bukit Changkuan reservoir to be fed by Padang Saga reservoir (if need
be). Secondary reservoirs booster stations and tanks get their supplied from falling
mains of the principal reservoirs.
16
2.1.5
Summary of Works Outputs
The combined works output capacity available in Langkawi may be
summarized as in Table 2.1
Table 2.1
Existing water supply schemes
Name of Installations
Designed Capacity
Average Daily
(Million Gallons per
Production (2003)
Day)
(Million Gallons per
Day)
A. Treatments Plants
Padang Saga ( phase III )
4.0
3.763
Padang Saga ( phase II )
1.2
1.068
Bukit Kemboja
2.4
1.805
Pulau Tuba
0.1
0.041
Sungai Baru
12.0
4.498
19.7
11.175
12
4.498
Telok Kedah
0.25
0.25
Kubang Badak
1.0
presently not operating
0.173
0.173
TOTAL
B. Booster Stations
Penarak
Malut
17
Table: 2.1
Continued..
Name of Installations
Designed Capacity
Average Daily
(Million Gallons per
Production (2003)
Day)
(Million Gallons
per Day)
C. Bunded Storages
Padang Saga
66.67
3.763
Padang Matsirat
24.44
1.068
1385.83
6.636
Padang Saga
3.0
3.0
Padang Lalang
3.0
3.0
Changkuan
1.0
1.0
Kuah
1.0
1.0
Dundong
1.0
1.0
Telok Nibong
1.0
1.0
Malut
1.0
1.0
Kubang Badak
0.33
0.33
11.83
11.83
D. Dams
Makut Dam
E. Reservoirs
TOTAL
18
2.2
TREATMENT PROCESSES
The treatment processes used in all treatment plants are generally similar,
employing conventional physical and chemical methods based standard JKR design.
The treatment processes are as summarized in table 2.2 below:
Table 2.2 – water treatment processes
Process
Raw water storage
Objective
To aid sedimentation, to reduce bacteria and to
help
in smoothening out fluctuations
between the raw water flow and demand by
acting as a buffer .
Screening – Coarse
To remove floating debris such as twigs, leaves
and even animals that can foul or damage
equipment, from entering the treatment plants.
- fine
To remove aquatic plants and small debris that
can clog or foul other processes.
Grit removal
To remove grit so as to prevent wear off
machinery and unwanted accumulation of
having inert matter.
Chemical pre treatment To control the growth of micro organisms that
affect taste, odour and color.
Aeration
To provide oxygen for the oxidisation of
dissolved iron and manganese to their insoluble
form, to liberate dissolved gasses
19
Table 2.2
Continued
Process
Objective
Like carbon dioxide and hydrogen disulphide and
thus releasing corrosiveness and removing odor and
to increase oxygen content thereby imparting as
sparkling appearance and “ fresh” taste to water.
Pre- chlorination
To reduce bacteria in highly polluted raw water, to
precipitate dissolved iron and manganese in raw
water, to prevent algae growth in sedimentation and
filter tanks, to neutralise excess ammonia content
and finally, to destroy slime organisms on filter
sand thereby prolonging filter runs.However pre
chlorination should be avoided if a raw water
contains high organic content because chlorine
reacts with organic matter (decay vegetation ) to
produce trihalomethanes which are carcinogenic.
Chemical mixing
To disperse coagulant and coagulant aids evenly
throughout the water
Coagulation and
To prepare water for sedimentation and filtration at
flocculation
economically high rates of flow by agglomerating
suspended particles and colloids into settle able
floc
Sedimentation
To remove settle able particles, bacteria and viruses
Filtration
To remove finally divided particles, carry over floc
and micro organisms
20
Table 2.2 Continued
Process
Adsorption
Objective
To remove color, taste and odor from water when
their presence is so excessive that conventional
treatment will not suffice.
Fluoridation
To raise the amount of fluoride in water so that
children consuming it will develop sound teeth
with a high resistance to decay
Disinfection
To kill micro – organisms which still remain in
water after filteration.
Conditioning
To deposit a protective coating on pipes, fittings
and plumbing to prevent corrosion of metal pipes
and fittings and to prevent the leaching of lime
from the cement of A.C. pipes and the concrete
lining of steel and ductile iron pipes and fittings.
21
2.3
Past Population and Water Demand Studies
2.3.1
Population Estimation
One of the requirements of the study is to forecast the water demand for
domestic consumption both spatially and at specified time interval. Forecast the
future is essential in order to provide information for the estimation of the domestic
demand for water. Table 2.3(a) and Table 2.3 (b) shows population projections
carried ou by Jurutera Konsultant Sendirian Berhad.(J.K.C.) in 1983 and Syed
Muhammad, Binnie and Ooi (S.M.H.B.) in 1992
2.3.2
Demographic Background
Administratively, Pulau Langkawi is divided into six mukims. These are
Ayer Hangat, Bohor, Kedawang, Kuah, Padang Matsirat and Ulu Melaka. Pulau
Tuba and pulau Dayang Bunting are included in Mukim of Kuah. In 1980, the
Langkawi Island had a population of 29,088 persons comprising 88.8% Malays,
7.4% Chinese, 3.0% Indians and only 0.8% other races. Fertility in Langkawi can be
considered as moderately high with 32.8 births per thousand population in 1986, a
rate slightly higher than tthat of the State of Kedah and many other states of west
Malysia. The crude death rate was 6.1 per thousand population. As a result, the rate
of increase was moderately high with a natural increase of 26.7 per thousand
population. Tablle 2.4 shows the population statistics obtained from the department
of statisstics, Malaysia.
22
Table 2.3(a): Population Projection by Jurutera Konsultant (1983)
Mukim
2000
Projected
Average annual
Population
Growth rate (%)
2005
2010
2015
2000-
2005-
2010-
2005
2010
2015
Ayer
Hangat
15000
21100
29600
41500
8.1
8.1
8.1
Bohor
3200
3500
3900
4300
1.9
2.3
2.3
Kedawang
4800
5200
5600
6000
1.7
1.7
1.7
Kuah
23700
31000
40400
52900
6.2
6.2
6.2
Matsirat
6800
7700
8700
9900
2.6
2.6
2.6
Ulu Melaka
5900
6700
7600
8600
2.7
2.7
2.7
Total
61320
77230
97930
12544
4.7
4.9
5.1
Padang
0
23
Table: 2.3 (b) Population Projection by S.M.H.B. (1992)
Projected
Mukim
Population
Average annual
Growth rate (%)
2000-
2005-
2010-
2000
2005
2010
2015
2005
2010
2015
Hangat
11422
15252
19860
25222
5.78
5.28
4.78
Bohor
5876
7877
10170
12647
5.86
5.11
4.36
Kedawang
9184
12013
15135
18366
5.37
4.62
3.87
Kuah
28646
38842
51367
66254
6.09
5.59
5.09
Matsirat
11487
15363
20035
25482
5.81
5.31
4.81
Ulu Melaka
8492
11020
13773
16580
5.21
4.46
3.71
Total
75107
10036
13034
164551
5.80
5.23
4.66
7
0
Ayer
Padang
24
Table 2.4 Population census from year 1970 – 2000
Mukim
Population
Average annual
Growth rate (%)
1970
1980
1991
2000
1970
1980
1991
-
-
–
1980
1991
2000
Ayer Hangat
3813
5339
7357
9401
1.6
3.4
4.78
Bohor
1887
3754
3927
5498
2.7
3.0
5.46
Kedawang
3413
3683
5679
8449
0.8
3.4
4.57
Kuah
8717
9150
12609
26602
0.5
3.4
7.09
Padang Matsirat
3813
4309
5938
9263
1.3
3.4
5.1
Ulu Melaka
3001
3705
5106
10468
2.4
3.4
5.21
24644
28383
42938
69681
Total
2.0
3.3
5.37
25
2.4
Past Studies on Per Capita Water Consumption
Table 2.5 shows the computation of Per Capita Water Consumption by Jurutera
Konsultant in 1983.
Table 2.5: Estimation of per Capita consumption projection by J.K.C.
PER CAPITA DEMAND – l/h/d
Mukim
2000
2005
2010
2015
Ayer Hangat
275
275
275
275
Bohor
225
250
275
275
Kedawang
225
250
275
275
Kuah
275
275
275
275
Padang Matsirat
225
220
275
275
Ulu Melaka
225
250
275
275
26
2.5
Hydrological characteristics of Langkawi
2.5.1
Rainfall
All four Jabatan Parit ans Saliran rain gauge stations on Pulau Langkawi have
sufficiently long term monthly rainfall records to allow for reliable statistical
processing. The consistency of the rainfall data was checked by means of the Double
Mass Curve Method and the results obtained were considered were adequate. The
average annual rainfall of the rain gauge stations used is listed in Table 2.6. The
average annual rainfall data is then checked with the result of three rainfall stations
on Pulau Pinang on the basis of similarity of hydrological and physical features.
Table 2.6
Hydrological similarity of Pulau Pinang and Langkawi
Annual
Station
Location
Rainfall
(mm)
Ulu Melaka
Langkawi
2415
Sg. Penghulu
Langkawi
2675
Ldg. Sg.Raya
Langkawi
2377
Pdg. Matsirat
Pulau Pinang
2605
Pintuair Bagan Air Itam
Pulau Pinang
2783
Telok Bahang No.23
Pulau Pinang
3166
Telok Bahang No.27
Pulau Pinang
3380
27
2.5.2
Evaporation and Evapotranspiration
Mean monthly evaporation measurements made by the JPS at Padang
Matsirat since 1963 are set out in the Table 2.7
Since the major part of the study area is covered by forest and tree crops an
estimate of the actual evapotranspiration has been based on evapotranspiration values
forest.Noieuwolt (9) in his paper on “Evaporation and Balances Of Malaya” has
noted that the evaporation tends to decrease with increase in elevation. Since the
catchments on the island are made up of highlands with elevations varying between
60M and 880M above sea level a reduction of 10 percent for elevation was applied to
the evapotranspiration recorded at Padang Matsirat. Consequently the annual average
evapotranspiration varies between 3.94 mm/day and 4.03 mm/day. As in Table 2.8
the highest mean monthly evapotranspiration is 4.67 mm/day recorded at the
Langkawi International Airport, which occurred in March.
Since the major part of the study area is covered by forest and tree crops an
estimate of the actual evapotranspiration has been based on evapotranspiration values
forest. Noieuwolt (9) in his paper on “Evaporation and Balances Of Malaya” has
noted that the evaporation tends to decrease with increase in elevation. Since the
catchments on the island are made up of highlands with elevations varying between
60M and 880M above sea level a reduction of 10 percent for elevation was applied to
the evapotranspiration recorded at Padang Matsirat. Consequently the annual average
evapotranspiration varies between 3.94 mm/day and 4.03 mm/day. The highest mean
monthly evapotranspiration is 4.67 mm/day recorded at the Langkawi International
Airport, which occurred in March.
28
Table:2.7 Evaporation Measurements Made by JPS at Padang Matsirat
Evaporation
Jan
Feb
Mar
Apr
Mei
Jun
Jul
Aug
Sept
Oct
Nov
Dec
Annual
Pan
206
201
209
170
142
136
140
141
134
136
142
179
1936
Open Water
181
182
196
159
134
124
141
126
124
118
127
151
1749
Type
Table : 2.8 Forest Evapotranspiration Pulau Langkawi Made by JPS
Month
Jan
Feb
Mar
Apr
Mei
Jun
Jul
Aug
Sept
Oct
Nov
Dec
Annual
Evapotranspiration
161
162
174
141
119
111
113
112
110
105
113
134
1555
(mm)
29
2.6
The Quality Of Water
2.6.1
Raw Water Quality Criteria
Appendix ‘A’ shows the recommended criteria for physical, chemical,
radiochemical and microbiological constituents of raw water, which will be suitable
as potable source after undergoing conventional treatment.
If raw water has quality that does not confirm with the recommended raw
water quality criteria, then appropriate action shall be taken to identify and overcome
the problem to allow for continued operation of conventional treatment. Special
treatment should be considered as a last resort.
2.6.2
Criteria For Drinking Water Standards
Drinking water must be clear, and does not have objectionable taste, colour. It
must be pleasant to drink and free from all harmful organisms, chemical substances
and radio active particles in amounts which could constitute a hazard to the health of
the consumer.
The quality of drinking water is measured in terms of its physical, chemical,
radiochemical and microbiological characteristics. Appendix ‘B” lists some of these
characteristics with their recommended standards, which shall not be exceeded for
maximum protection of the consumer.
If the characteristics or constituents in water after repeated sampling exceed
the recommended standards, then it shall be investigated by the personnel of the
Health Department and the water purveyor immediately to ascertain the cause and to
remove the source of contamination. If these measures fail repeatedly the public
shall be notified and possibly an alternative source of supply should be sought.
30
2.6.3
The quality of raw water sources of Pulau Langkawi
(Samples And Results Of The Analysis)
Samples of water from the Malut Reservoir, was collected by by the SMHB
consultants and analysed for physical and chemical and treatment tests. The point of
sampling and results of the analysis are as per Table 2.9(a) and Table 2.9(b). The
water level of Dam at 8.10 am on 9th June 1992 was 71.00m. due to presence of
suspended matter, reading was not taken as it would
Table: 2.9(a)
be inaccurate
Point of Sampling at Malut Dam
Distance from
Sample
Location
No.
Datum Level
Water Surface
(M)
( M)
1
Water Surface
71.0
0
2
1.60m below
69.40
2.43
69.57
2.43
3.20m below surface
67.8
3.20
4.80m below surface
66.20
4.80
Top of concrete 3rd
62.17
8.83
surface
3
Top of concrete of
2nd draw off
4
5
6
draw off
31
Table2.9(b): Results Of Analysis
Sample No.
1
2
3
4
5
6
PH
7.4
7.4
7.4
7.2
0.68
6.25
Turbidity
4.4
4.8
4.5
5.02
12.3
*
Colour
<5
40.0
45
60
80
500
Conductivity
50.4
50.3
50.4
50.7
55.4
88.4
Alkalinity
21.0
19.50
20.0
20.0
22.0
-
Hardness
17
-
-
-
-
-
Iron
0.01
0.04
0.01
0.09
0.09
5.60
Manganese
0.07
0.10
0.10
0.20
0.20
0.84
Parameters
32
2.7
Analysis of Pipe Networks
In the context of pipe systems for fluid distribution the term ‘network
analysis’ describes the investigation of the complex relationships between the
network specification, the consumption, the pressure and the flow.
Network analysis is a well-established technique helping the engineer to
understand the behaviour of water networks. It is seen as an important part of supply
and distribution system management. Among its many uses are:
o
Design of new systems and reinforcement of existing
networks,
o
Assessment of network capacity,
o
Design of district metering schemes for leakage control,
o
Design of pressure control schemes,
o
Investigation of pumping to save costs,
o
Provision of information for investigations of water quality,
consumer demand and pipe deterioration etc.
Network simulation is an extension of network analysis which describes the
operation of a network over a period of time. In this case, a profile of demand and a
specification of operating conditions for a example pump switching during the
stimulated time are required. Network simulation is essentially a series of network
analysis throughout the simulated time. Account is taken of the effects of demand
and the operation upon storage (at reservoirs) and upon the status of network
equipment (pumps and valves).
Network simulation extends the scope of network analysis in the
investigation of operational aspects. In addition to providing further information for
the uses, network simulation is useful for:
o
Detailed pumping pumping simulation,
o
Assessment of diurnal effects of demand and operation,
o Assessing reservoir performance,
33
o Monitoring of supply and distribution by providing values such as pressure,
flow with which to compare measured values.
2.7.1
Historical Development
Traditional network analysis is performed to investigate the network at a
single point in time under specified demand conditions. The analysis essentially
calculates pressures, flows and associated values for that time. The analysis requires
a network model description and an appropriate demand specifications.
In any pipe network, the following two conditions must be satisfied.
(i)
The algebraic sum of the pressure drops around a closed loop must be zero,
that is there can be no continuity in pressure.
(ii)
The flow entering the junction must be equal to the flow leaving the same
junction, that is the law of continuity must be satisfied
Based upon these two basic principles, the pipe networks are generally solved
by the methods of successive approximation, because any direct analytical solution is
not possible as the same will involve various equations to be solved simultaneously
and many of which are non – linear. The difficulty of making network analysis
calculation stems from the non - linear relationship between pressure drop and flow,
and from the interconnected networks. In particular the existence of loops in a
network exclude the possibility of solving the system one component at a time.
Early approaches to systematically solving network analysis were essentially
based on the Hardy Cross method, and iterative calculation method which is tedious
to perform without a computer and which can be unreliable for certain networks. The
Hardy Cross Method is also known as the single path adjustment method and is a
relaxation method . The flow rate in each pipe is adjusted iteratively until all
equations are satisfied. The method is based on two primary physical laws:
34
(i)
The sum of pipe flows into and out of a node equals the flow entering or
leaving the system through the node.
(ii)
Hydraulic head ( elevation head + pressure head, Z+P/S ) is single – valued.
This means that the hydraulic head at a node is the same whether it is computed from
upstream or downstream directions.
( L = Pipe Length, Z = elevation of node, P = Pressure node, S = Specific weight of
Fluid, Z+P/S = Hydraulic head (also known as piezometric head)
Pipe flows are adjusted iteratively using the following equations, until the change in
flow in each pipe is less than the convergence criteria
# pipes in loop
 Hi
i=1
Qi
=

# pipes in loop
n 
(
… 1
Hi
i = 1 (  )
(
Qi
(http://Imnoeng.com/Pipes/PipeNetwork.htm)
Q = Flow rate through pipe, or into out of the node ( also known as discharge or
capacity)
H = Head losses in pipe ( can also known as discharge or capacity)
n = Constant used in Hardy Cross. n = 2 for Darcy Weisbach losses or 1.85 for
Hazen William losses