Kaden_Zian_CIV_FinalReport

Griffith School of Engineering
Griffith University
4005ENG – Industry Affiliates Program
Water Supply and Sewerage
Network Analysis
Zian Kaden
S2798983
10 June 2014, Semester 1
Sedgman Yeats
Bogdan Popa
Nick Cartwright
A report submitted in partial fulfilment of the degree of 1310 Bachelor of Engineering
The copyright on this report is held by the author and/or the IAP Industry Partner. Permission has been granted to Griffith University to keep
a reference copy of this report.

4005ENG – Industry Affiliates Program, Semester 1, 2014
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EXECUTIVE SUMMARY
Water supply and sewerage networks are an integral part of design, planning and developing
sub divisions. It is a necessity for infrastructure and communities, therefore developing an
efficient and cost effective design are paramount. To create sustainable environments and eco
systems all waste water and discharge must be treated before being released or reused.
Following severe droughts, Gold Coast City Council in the year 2004 implemented a recycled
water system to be used alongside potable (drinking) water systems, known as dual
reticulation. On the 12th
of December 2013 the decision was made to progressively
decommission the recycled water network and return to solely using potable pipe networks.
This was done to dramatically reduce costs across the board. It is estimated the return to a
traditional potable pipe network will save rate payers $114 Million on the Gold Coast over 40
years.
Relevant literature for the project consists of Water Services Association of Australia
(WSAA), SEQ Water Supply and Sewerage Design & Construction Code – Design Criteria
and Gold Coast City Council Planning Scheme – Land Development Guidelines. An in-depth
review of literature was undertaken to determine the inputs and methodology to be used in
designing the water supply and sewer networks. A preliminary design must first be drawn by
hand and input into AutoCAD. When designing water supply the major parameter governing
the design is fire flow, which adds a significantly higher flow demand to a particular point in
the system, it is important that this demand and the demand of all other lots can be met
simultaneously.
The second project component is a sewer network design and analysis which uses a gravity
flow principle for all sewer output flowing downward to a discharge point such as a trunk
sewer. A manhole is used for every change in direction along with a minimum spacing
requirement. Similarly a preliminary design must be drawn by hand and input into AutoCAD
before the design process can initiate.
The final outcome of the project is to compare results and investigate any discrepancies
between outcomes of first principles and design software analysis. Another outcome is to
compare how the different methods use inputs to create outputs. Results have shown that

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software and first principles are very similar in their outputs, but the larger the subdivision
becomes the more difficult and complex the first principles approach proves to be. Contrary to
this, design software is capable of detailed designs involving much larger and difficult
subdivisions, involving a similar amount of work and difficulty.

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ACKNOWLEDGEMENTS
I would like to acknowledge the following people that have guided and supported me through
this project. Without their help and encouragement, this project would have been significantly
more challenging and would have required a greater length of time to achieve the same
standards and outcomes.
Firstly I would like to thank my family for supporting and encouraging me for the duration of
the project. They always helped where possible and made aspects of completing the project
and work life easier. I would not have been able to achieve this outcome without their help.
Nick Cartwright has been a great academic advisor; his help has kept the project on track in
terms of the academic standards and deliverables. He would always make time to speak with
me and was very supportive in the direction the project was going. His advice was very clear,
direct and understandable, which I appreciate.
Bogdan Popa is the industry supervisor overseeing this project. He has educated and guided
me in many areas that were foreign to me. He has provided invaluable experience, which I am
very grateful for. Bogdan was always willing to give me feedback and support, but on the
other hand would push me to learn and develop things on my own. Without his help this
project would not have been able to be completed to the standard that it is.
Finally, I would like to thank the rest of the Sedgman Yeats Southport office for their
continuous support and friendly attitude. The have been very welcoming and easy to fit in
with. I appreciate all the experience and knowledge I have gained from them. In particular
Miles Glasson is an invaluable help with regards to AutoCAD, he allowed the project to move
forward at a consistent rate, where it otherwise could have significantly slowed and required
substantial time to overcome issues.

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TABLE OF CONTENTS
EXECUTIVE SUMMARY...................................................................................................I
ACKNOWLEDGEMENTS.............................................................................................. III
1 INTRODUCTION............................................................................................................. 1
2 CODES AND STANDARDS............................................................................................ 4
2.1 Introduction................................................................................................................... 4
2.2 Water Services Association of Australia (WSAA)....................................................... 4
2.2.1 Water Supply Code of Australia ............................................................................ 4
2.2.2 Sewerage Code of Australia................................................................................... 5
2.3 Southeast Queensland Water Supply and Sewerage Design and Construction Code
(SEQ WS&S D&C Code) – Design Criteria.......................................................................... 6
2.3.1 Water Supply Standards......................................................................................... 6
2.3.2 Sewer Standards ..................................................................................................... 7
2.4 Gold Coast City Council (GCCC) Planning Scheme, 2003 Policy 11 – ...................... 8
Land Development Guidelines............................................................................................... 8
2.4.1 Water Supply Standards......................................................................................... 8
2.4.2 Sewer Standards ..................................................................................................... 9
3 INITIAL PROCESS AND MODELLING ................................................................... 10
3.1 Investigated Site.......................................................................................................... 10
3.2 Water Supply Network Layout (Process by Hand)..................................................... 12
3.3 Sewerage Network Layout (Process by Hand) ........................................................... 14
3.4 Layout Input into AutoCAD ....................................................................................... 16
4 WATER SUPPLY NETWORK ANALYSIS ............................................................... 17
4.1 Initial Calculations and Information ........................................................................... 17
4.2 First Principles Analysis ............................................................................................. 20
4.2.1 Results.................................................................................................................. 22
4.2.2 Discussion ............................................................................................................ 31
4.3 H20Map Analysis ....................................................................................................... 32
4.3.1 Results.................................................................................................................. 37
4.3.2 Discussion ............................................................................................................ 41
4.4 EPANET Analysis ...................................................................................................... 42
4.4.1 Results.................................................................................................................. 44

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4.4.2 Discussion ............................................................................................................ 48
4.5 Water Supply Network Analysis and Comparison ..................................................... 49
5 SEWERAGE NETWORK ANALYSIS........................................................................ 51
5.1 Initial Calculations and Information ........................................................................... 51
5.2 First Principles Analysis ............................................................................................. 53
5.2.1 Results.................................................................................................................. 55
5.2.2 Discussion ............................................................................................................ 59
5.3 EPA SWMM Analysis................................................................................................ 60
5.3.1 Results.................................................................................................................. 62
5.3.2 Discussion ............................................................................................................ 64
5.4 Sewerage Network Analysis and Comparison .......................................................... 65
6 CONCLUSION................................................................................................................ 67
7 REFERENCES................................................................................................................ 68
APPENDIX ......................................................................................................................... 70

1 Water Supply and Sewerage Network Analysis
1 INTRODUCTION
This report outlines the water supply and sewerage network analysis undertaken for the
subdivisions of Development A and Development B located in Pimpama. The industry
partner for this project is Sedgman Yeats and completed under the guidance of an industry
advisor at the office. While the project has been monitored and assessed by Nick Cartwright,
academic advisor at Griffith University.
Water supply networks consist of a pipeline which travels from a source such as a reservoir
under pressure which progressively lowers together with the pipe diameter, as it travels
further down the line, splitting off into subdivisions. As this water main travels, it supplies
infrastructure along the way and in this project, water mains connect to a branch network of
pipes which supply the lots within a subdivision. Sewer networks work in an opposite fashion,
where discharge flows downward using gravity, from an end user through a series of pipes to
a treatment plant or pump station. In this project a gravity sewer system is used, which utilises
a large branch pipe network directing all the accumulating flow toward an existing trunk
sewer, which further connects onto a larger trunk leading to a sewerage treatment plant.
The purpose of this report is to undertake an investigation to find differences and similarities
between methods of first principles and design software, where conclusions will be drawn as
to determine the viability of EPANET to be used alongside H20Map as a method to confirm
results, endorsing H20Map as appropriate industry wide standard software. This involves
modelling the networks based off strict codes and standards set out by several governing
bodies in the water supply and sewerage sector. Similarly the viability of EPA SWMM, by
comparing with first principles methods, to be used as an analysis design tool for sewer
networks will be assessed. The project will also optimise the networks and deliver the final
pipe sizes and network layout for the subdivisions.
Gravity sewers create certain flow situations, such as in this project, the flow remains
consistent and steady through each section of pipe. Kinematic flow refers to the branch of
mechanics that studies the motion of water without consideration for its mass or force acting
on it, where characteristics of the flow such as velocity, pressure, density etc. change with
time (Free Dictionary, 2014). Steady flow refers to the flow of a fluid where characteristics
such as velocity, pressure, density etc. do not change with time (Clayton. T.C, 2009, p.80).

ZianKaden–S2798983 2
Water supply and sewerage is a fundamental requirement to the safe development of
infrastructure and the future use thereafter. This is why they must be designed accurately and
efficiently to effectively cope with peak demands. The project hopes to develop a complete
analysis of water supply and sewerage networks utilising first principles, H20Map, EPANET
and EPA SWMM.
First principles involve using theory calculations to develop a process by which a network of
pipes can be analysed for certain parameters, by means of Microsoft Excel. H20Map is a
powerful commercial design software tool, providing detailed water supply design, made to
be used in conjunction with AutoCAD as well as GIS software. H20Map recognises inputs
from AutoCAD such as the pipe/ junction network, pipe lengths and the elevation of each
junction through the use of contours. Manual inputs included, pipe sizes, Hazen Williams
roughness, demand pattern and demand lots used to calculate flow rates.
EPANET is free water supply design software provided by the United States Environmental
Protection Agency and significantly simpler to understand compared with H20Map. A
background image can be input into the software, but the entire network is still required to be
drawn and all inputs, except for pipe lengths, manually entered. This process is far more time
consuming compared to H20Map, especially when designing a large subdivision such as
Development A.
EPA SWMM is freeware provided by the US Environmental Protection Agency, which is first
and foremost used as a storm water management model, but can also be used to model gravity
sewer systems which is the purpose for this project. Similarly to EPANET a background
image input can be used to draw the sewer network. All other numerical inputs must be
manually entered, except for pipe lengths, which create a time consuming process. Inputs
consist of invert sewer heights, Manning’s coefficient, maximum flow depth and flow
demands.
As part of comparing first principles and design software a review of literature and
conducting research into the field of water supply and sewerage is necessary to gain an
understanding of what others have experienced using these methods. EPCM Consulting
conducted a water supply and sewerage network analysis for a proposed development at
Ferny Hills in North Brisbane. In the report they detailed the method and use of EPANET and
EPA SWMM. This analysis was completed to determine the feasibility of the project before

detailed design would initiate. The report concluded successful results and accurate use of the
two freeware’s (EPCM, 2011).
The governing bodies who determine the design and analysis of water supply networks are
Water Services Association of Australia (WSAA), which contains two separate codes, a water
supply code and sewerage code. Southeast Queensland Water Supply and Sewerage Design
and Construction Code (SEQ WS&S D&C Code), which covers the majority of the initial
design calculations. Gold Coast City Council (GCCC) Planning Scheme. 2003 Policy 11 –
Land Development Guidelines, which consists of the most relevant information towards many
aspects of the design and analysis process. Both SEQ and Gold Coast standards hold
precedence over WSAA.
1.1 Report Structure
Section 1 introduces the project and the surrounding concepts. Briefly explains the topics of
water supply and sewerage design and analysis and their importance. This section will also
present the aims and objectives of the project and the process required to achieve them.
Section 2 details the literature involved in the project, defining each, explaining their
importance and which sections from within the respective literature is used for this project.
Section 3 first introduces the subdivisions and their locations, along with their lot layouts and
construction stages. Secondly, the processes involved in the preliminary design are detailed to
prepare for the main purpose of the project which is analysis.
Section 4 explains the processes involved in the analysis of water supply networks using first
principles, H20Map and EPANET. Following this, results for each section are presented,
where each will be analysed and compared.
Section 5 details the processes involved in the analysis of sewerage networks using first
principles and EPA SWMM. Following this results for each section are presented, where each
will be analysed and compared.
Section 6 summarises the findings of the project resulting from the analysis and comparison,
leading to conclusions.

2 CODES AND STANDARDS
2.1 Introduction
The literature for this project comprises of standards and codes set out by Water Services
Association of Australia (WSAA). The Southeast Queensland Water Supply and Sewerage
Design and Construction Code and Gold Coast City Council (GCCC) Planning Scheme, 2003
Policy 11 – Land Development Guidelines, review and modify the WSAA codes and standard
drawings to create a set of standards for their respective regions, which have precedence over
WSAA. Standards which are not covered by either will then be referred back to Water
Services Association of Australia. The codes and standards regulate in its entirety the design
and construction of water supply and sewerage networks; this is done to create a uniform
standard across Australia.
The purpose of these governing bodies is to create a consistent and minimum standard for
Australia and each region within. There are many aspects which require careful consideration
to design an adequate and properly functioning water supply and sewerage network.
2.2 Water Services Association of Australia (WSAA)
WSAA was formed in 1998 and is the peak body representing the nation’s urban water
industry. WSAA also continues to conduct research and advocates on behalf of the industry,
as well as regularly organising industry events and seminars (WSAA, 2014). WSAA consists
of the Water Supply Code of Australia and the Sewerage Code of Australia. The current
version for water supply is from 2011 and sewerage from 2002.
2.2.1 Water Supply Code of Australia
The water supply code acted as a strong base to begin research and provided the project with
valuable information to use when reviewing the other standards for design. All aspects of
design are covered by Gold Coast City Council (GCCC) Planning Scheme, 2003 Policy 11 -
Land Development Guidelines and SEQ Water Supply and Sewerage Design & Construction
Code, for water supply.

2.2.2 Sewerage Code of Australia
Similar to water supply the majority of design constraints are in the other standards, as they
hold precedence, although a few preliminary standards are used. Table 1 below details the
preliminary number of equivalent population which can be serviced on a certain diameter
pipe.
‘Peak Wet Weather Flow (PWWF)’ is the major demand used in sewer design. This
parameter is outlined in the Sewerage Code of Australia, as the design flow, which is the peak
wet weather flow within a gravity sewer:
Pipe Size (DN) Maximum Allowable EP
150 600
225 1600
300 3200
Table 1. EP Capacity Limitations for Reticulation Sewers (Sewerage Code, P.64)
(EP refers to ‘Equivalent Population’)
Figure 1. Design Flow of Gravity Sewer (Sewerage Code, P.110)

2.3 Southeast Queensland Water Supply and Sewerage Design and Construction
Code (SEQ WS&S D&C Code) – Design Criteria
The Queensland Government required the five water supply and sewerage service providers
in South East Queensland (Gold Coast City Council, Logan City Council, Queensland Urban
Utilities, Redland Water and Unitywater) to develop a uniform code for the design and
construction of new water supply and sewerage assets (SEQ Code, 2013). To date there has
only been a single publication of the SEQ Code which was the 1st
of July 2013. The code
covers the major aspects of design, such as the demand patterns for different scenarios and
other important constraints integral to the design of water supply and sewerage networks.
The following sections summarise the relevant design parameters extracted from the SEQ
WS&S D&C Code.
2.3.1 Water Supply Standards
The water supply standards contain key information in relation to the design, such as the
minimum and maximum operating pressures, maximum velocity and many other constraints.
No. Parameter Gold Coast
A1 Average Day Demand (AD) per EP, excluding NRW 220 L/EP/d
A2
Peaking Factors:
MDMM/AD
PD/AD
PH/PD
PH/AD
Residential:
1.75
2.12
2.84
6.03
A3
Minimum SERVICE Pressure,
Normal Operating Conditions
22m
A4 Maximum SERVICE Pressure
Target Maximum pressure: 55m
Maximum pressure: 80m
A5
Fire Fighting:
Urban
Background Demand
Residential: 15 L/s
for 2 hours
2/3 PH (not less than AD)
A9 Maximum Allowable Velocity 2.5 m/s
Table 2. Water Supply Network Design Criteria –
Single Supply (Drinking Water Only) Network (SEQ WS&S D&C Code, P.13)

2.3.2 Sewer Standards
Similar to water supply standards, sewer standards contain key information involved in the
design such as peak wet weather flow calculations, minimum grades and velocity constraints.
Table 3 summarises the applicable flow parameters for sewer design.
No. Parameter Gold Coast (Pimpama)
D1 Smart Sewer Option NuSewer
D2 Average Dry Weather Flow (ADWF) 180 L/EP/d
D3 Peak Dry Weather Flow (PDWF)
Where
D4 Peak Wet Weather Flow (PWWF)
D8
Maximum Flow Depth
Minimum Velocity
Maximum Velocity
75% d (at PWWF)
0.7 m/s at PDWF
3 m/s
All pipe connections and lengths have specific minimum grades which must be met. The
purpose of this is that the flow in a particular pipe, servicing a particular number of lots can
reach an adequate velocity. If a required velocity is not met, particles can form blockages and
pipe erosion will take place. Table 4 summarises the minimum pipe grades allowed for
specific pipe diameters.
Nominal Bore (mm) Slope
100 House Connection branch, one allotment only at 1:60
150
House connection branch and/or sewers for first 10
allotments: 1:100
Sewer after first 10 allotments: 1:180
225 1:300
300 1:400
375 1:550
450 1:700
525 1:750
600 1:900
Table 3. Sewerage Network Design Criteria (SEQ WS&S D&C Code, P.28)
Table 4. Minimum Sewer Grades – Gravity Sewer Requirements
(SEQ WS&S D&C Code, P.28)

2.4 Gold Coast City Council (GCCC) Planning Scheme, 2003 Policy 11 –
Land Development Guidelines
The GCCC Planning Scheme, details many aspects of water supply and sewerage network
design and hold precedence over WSAA. The latest version of Policy 11: Land Development
Guidelines, Section 4, is 2005 with amendments made in 2013. The water supply and
sewerage reticulation sections have been based on Queensland Water Resources Guidelines
and earlier editions of Council's specifications and guidelines to provide a more performance
orientated approach (GCCC, 2013). The latest versions of all standard drawings are 2008.
This section will detail the standards used in the design of water supply and sewerage for the
two subdivisions in Pimpama.
2.4.1 Water Supply Standards
 Traditional Potable reticulation mains shall be coloured blue and be of the following
diameters: 100mm, 150mm, 200mm, 250mm and 300mm. (GCCC Section 4, p.13)
 Water supply mains are to be located 1500mm off the property boundary. (GCCC,
Standard Drawing No. 08-06-001)
 Hydrants shall be spaced at a maximum of 80 metres. (GCCC Section 4, p.19)
Table 5 provides an indicative pipe capacity in relation to the number of lots connected.
Nominal Size of Potable Main
(Diameter mm)
Nominated Capacity of Main for
Residential Single Family Domain Lots
(ETs) (Single supply point only)
PE100 – 63OD 14 ET
PE100 – 110OD 50 ET
PVC – DN150 250 ET
(ET refers to ‘Equivalent Tenement’)
Table 5. Number of Lots Serviced per Pipe Diameter (GCCC Section 4, p.11)

2.4.2 Sewer Standards
 Non-pressure reticulation pipes shall be of the following diameters: 150mm, 225mm
and 300mm. (GCCC Section 5, p.5)
 Reticulation sewers are to be offset 1500mm from rear and side boundaries. Also to be
located 1600mm off the property boundary. (GCCC, Standard Drawing No. 09-07-
001)
 Manholes shall not be more than 90m apart. (GCCC Section 5, p.11)
 Maintenance shafts shall not be more than 80m apart. (GCCC Section 5, p.11)
Table 6 summarises the minimum cover requirements for sewer pipes.
Location Depth per DN
Allotments 0.45m to top of DN100 to DN 225 pipes
Allotments 0.60m to top of DN300 pipes
Footpath 0.6m to top of pipe
Roadways 0.9m to top of pipe
Table 6. Council’s minimum cover to top of a reticulation sewer
(GCCC Section 5, p.9)

3 INITIAL PROCESS AND MODELLING
3.1 Investigated Site
The subdivisions which the project is based on are located in Pimpama, with the main site is
located directly west of Development B. Development A comprises of 628 lots separated into
3 precincts, with precinct 1 being further divided into 3 stages. Development B comprises of
95 lots divided over 4 stages, but is designed as a whole. The land which Development A and
B are located on has already been cleared and prepared for services to be installed, as per
Figure 2.
Figure 2. Cleared Subdivision Site (Adapted from Google Earth)

The site locality plan shows the location of each precinct and stage within the two
subdivisions.
Figure 3. Site Locality Plan (Adapted from AutoCAD)
Legend:
1- Development B
2- Development A Stage 1, Precinct 1
5- Development A Precinct 1

3.2 Water Supply Network Layout (Process by Hand)
A lot layout plan for the subdivision is printed off from AutoCAD to be used for preliminary
design. Firstly junctions are drawn for every intersection or turn that represents a change in
direction, dead ends and connection points. From this, pipes are drawn connecting between
the junctions through the centre of the roads for diagrammatical purposes. In reality water
supply pipes are located 1.5m from the lot boundary within the road verge.
Catchments are used to represent the number of lots creating demand through a specific
junction. For ease of calculation, catchments are generally kept between 4 and 16 lots. To
improve the flow and look of the design catchments are kept as square or rectangle as
possible. This can be quite difficult at times to design, but will improve processes down the
path. The Gold Coast Policy 11: Land Development Guidelines, Section 4, contain
information used to determine preliminary pipe sizes before design is undertaken to test
whether or not they are sufficient.
Existing council water mains are shown in figure 4 as green lines, to determine connection
points for the reticulation network. These connection points are known as boundary
conditions, for this project they are modeled as reservoirs. GCCC has provided hydraulic
grade line pressure values, which is the overall pressure, for each connection point extracted
from Council’s models. Once all necessary information is mapped out, the stage and precinct
boundaries are included.
In the design of Development A 150mm and 100mm pipes connect to the existing council
mains. Following most 150mm pipe connections 100mm pipes could be used, but for ease of
construction and reduced costs 150mm pipes are used all the way through between reservoir
connection points. Changes in pipe sizes are reduced as much as possible due to the fact, this
increases construction time as different pipe beddings and depths are required as well as
having to use step up or step down fittings. Within precinct 3 the 150mm main runs all the
way through to the main round about in Development A.
The western most region of precinct 3 contains a circuit, where all the lots contained within
are of high elevations compared to their surrounding lots which meant a 150mm pipe was
needed to be run all the way around. There is vacant land between precinct 1 and 3 shown as a
future development, based on the land size a rough estimate of 30 lots was given to the area
and a 150mm pipe was run all the way to the edges of the land.

Figure 4. Water Supply Network (Adapted from AutoCAD)
Legend:
4
5
6
3
2
1

3.3 Sewerage Network Layout (Process by Hand)
The same lot layout plan is printed off and used for preliminary sewerage design. This project
and subdivision is based on a gravity sewer design, meaning a network of pipes all flow
downward by means of gravity towards a discharge point, which in this case is a trunk sewer.
A sewer system is based on a branch structure, where there are many small branches
throughout a network, all flowing towards a single point such as a large trunk.
The first step in the process is to determine the direction each lot is falling, maintaining that
the fall direction is perpendicular to the contours. Lots which are flat, low grades or are
special conditions will be graded, as to fall towards the road. Lots which fall to the rear of a
property will require a rear of allotment sewer line, which is less than ideal for both council
and home owners. The reason is that when a sewer line has to be placed rear of allotment it
creates difficulties for GCCC to access and perform maintenance, as well as an increased cost,
which in turn will create hassles for the home owner. This is one of the reasons lots are graded
towards the road where possible, but within the budget of the project.
Once the direction of lots is determined, the process of drawing sewer lines and junctions is
initiated. Several lines are able to meet up and combine into one line, as this is part of the
principle of sewer design. A junction is used to represents a manhole, which is used at any
change in direction, connection of pipes, beginning of a pipe section and intersection. There is
a minimum requirement that manholes are spaced no more than 90m apart; where a manhole
is not needed, maintenance shafts are generally used.
The pipe line is drawn following the standards, so that when running along a road it is 1.6m
off the lot boundary and 1.5m within the lot boundary when running at the rear of properties.

Figure 5. Sewer Network (Adapted from AutoCAD)
Legend:

 CP- Copy
 BR- Break Polyline
 MA- Match Properties
 TR- Trim Polyline
 CH- Properties
 XREF- External References (e.g. contours)
 LA- Layers (View list of layers in CAD
drawing and their status)
3.4 Layout Input into AutoCAD
The preliminary hand designs are to be input and replicated on AutoCAD to create the
electronic version. Sedgman Yeats has already set up the AutoCAD base templates and
created easy to use short cut controls. There are set lists of icons to use for certain types of
drawings, e.g. water supply networks.
Commands used in AutoCAD drawing include:
When drawing the water supply network, it is paramount that each line connecting between
junctions is separate to one another, as to ensure that when it is input into H20Map it will
convert the polylines into separate pipes and junctions. Each line set is on a different layer so
that it can be isolated and easily input into other software. Once the process of drawing is
completed the design can be input into the specific software.

4 WATER SUPPLY NETWORK ANALYSIS
4.1 Initial Calculations and Information
Water network analysis is the process of investigating a system of pipes for specific design
parameters, set by the respective governing bodies. These parameters include residual
pressure, flow demand, head loss, velocity and available flow. Each pipe section is
investigated separately while taking into account the previous pipe which it is connected to.
Once the model has been set up, demand patterns need to be calculated using SEQ Code
specifications. Non-revenue water (NRW) refers to the water lost through the water supply
network, which is not used by any person or infrastructure. From SEQ Code table 4.1 average
day demand (AD) per person and NRW per person is given. The EP/ET conversion is located
in the appendix of this report. This is used to convert AD and NRW from EP to ET units.
For the purpose of this project it was decided to analyse 5 junctions per precinct in
Development A to do a comparison with rather than all junctions in each precinct, as this is
just as effective without becoming confusing or requiring too much space. Because
Development B only has 9 junctions, all are analysed.
Table 7 shows the calculation process to determine the total AD.
Water Supply Demand Table
AD 220 L/EP/d (SEQ Code - Table 4.1)
NRW 20 L/EP/d (SEQ Code - Table 4.1)
Fire Demand 15 L/s (SEQ Code - Table 4.1)
Fire Flow Condition Fire flow conditions use 2/3 PH demand
EP/ET 2.73 (SEQ Code - Appendix A)
ET 628 Lots Development A
ET 95 Lots Development B
AD 600.6 L/ET/d (EP/ET) X AD (L/EP/d)
NRW 54.6 L/ET/d (EP/ET) X NRW (L/EP/d)
Total AD 655.2 L/ET/d AD + NRW
Table 7. Table detailing water supply demands

Demand (L/ET/s)
PH/AD demand is 0.0425 L/ET/s which is the demand pattern used in first principles
calculations and design software. It is the maximum demand that can possibly be used under
regular conditions.
The Hazen-Williams equation is used to calculate the head loss of water within a pipe at
ordinary temperatures. Hazen-Williams is simpler to use when compared to other equations
such as Darcy-Weiscach method, because the coefficient (C) is not a function of velocity or
duct diameter (LMNO, 2001).
Where:
EP – Equivalent Population AD – Average Day Demand
ET – Equivalent Tenement NRW – Non-Revenue Water
A table is created to calculate the PH/AD demand in L/ET/d,
which will be used as the demand pattern for calculations.
Demand Demand
Scenario Peaking Factors L/ET/d L/ET/s
AD N/A 600.6 0.0070
MDMM/AD 1.75 1105.7 0.0128
PD/AD 2.12 1327.9 0.0154
PH/PD 2.84 1760.3 0.0204
PH/AD 6.03 3676.2 0.0425
Table 8. Table detailing water supply demands (SEQ Code – Table 4.1)
MDMM – Mean Day Max Month Demand
PD – Peak Day Demand
PH – Peak Hour Demand

Hazen-Williams Equation for head loss:
(GCCC Section 4, P.11)
Where:
H = head loss in metres
L = total length in metres
Q = flow rate in litres per second
D = diameter in mm
C = Hazen-Williams Factor
Typical Hazen-Williams ‘C’ Factors are presented in table 9.
Pipe Friction Loss – Hazen-Williams Friction Factor
Mains Diameter (mm) C Value
100 100
150 100
200 110
250 110
300 110
Residual Pressure Calculation:
m) =
Table 9. Hazen-Williams Friction Factor (SEQ Code – Table 4.1)

The location of each connection point to Gold Coast City Council water mains is specified in
figure 4 above. The respective HGL pressure at each location is presented below:
HGL Information for Development A and Development B
Point/ Location Standard Flow HGL (m) Fire Flow HGL (m)
1 60.85 71.76
2 56.83 68.52
3 55.46 66.70
4 55.49 66.56
5 53.10 64.07
6 52.73 62.14
4.2 First Principles Analysis
When using first principles the demand lots that remain in a system past a particular junction
need to be included as demand on that current junction. The demand pipe flow through a
particular section of pipe is determined by the demand pattern multiplied by the number of
lots. Only one junction per catchment can contain a demand therefore junction 2 of
Development B contains no demand, as shown in figure 6 below.
The demand flow rate is used as the (Q) in the Hazen-Williams equation as well as being used
to calculate velocity. A pipeline table is created to ultimately calculate head loss, which is
then used in a junction table to find residual pressure. Each junction and reservoir is given a
number on AutoCAD to ease the process of first principles calculations by making it easier to
assess each pipe length.
Table 10. HGL Information (GCCC, 2013)

Fire flow uses a similar calculation method as regular conditions but adds 15 L/s to a specific
junction with the entire network requiring 2/3 peak hour demand as specified in the Gold
Coast standards. This increased demand is used by fire fighters through means of a hydrant
and need to be supplied with 15 L/s for a minimum of 2 hours while lots in the same network
still have adequate pressure for normal functions. This dramatically increases head loss and
velocity, while decreasing pressure. If any failure will occur in terms of the pressure reaching
a critically low level or velocity exceeding 2.5 m/s, it will happen during a fire flow scenario.
Once completed optimization of the water supply network can begin, such as altering pipe
diameters and their locations to modify parameters and ultimately to reduce costs.
Development A was then designed following this method, except the analysis process had to
be done in the stages and precincts specified for construction. This meant at each stage of
analysis, future precincts were kept in mind as they would change pressures throughout the
system. Development A has many reservoir connection points and for precinct 2 and 3, it was
decided to use the main one for the respective precincts as shown in figure 4. This is due to
the fact that when multiple reservoirs are connected their pressures meet at certain points and
combine creating a larger pressure further into the system where otherwise pressure would
have been too low. Calculating this manually is too difficult and inaccurate, making it far
more efficient to use a single reservoir connection point.

4.2.1 Results
Developement A and Development B Junction Layout
Figure 6. Numbered junctions assessed as part of results (Adapted from AutoCAD)

Development B-Regular Conditions
Pipeline Table
From
Junction
To
Junction
Length (m)
Roughness
C
Pipe Diameter Pipe Area Demand Demand PH Pipeflow Velocity
(m/s)
Head Loss
(m)(mm) (m^2) (Lots) (L/ET/s) Demand (L/s)
R1 1 79.89 100 150 0.0177 84 0.0425 3.57 0.202 0.051
1 2 26.13 100 150 0.0177 45 0.0425 1.91 0.108 0.005
2 3 71.49 100 150 0.0177 30 0.0425 1.28 0.072 0.007
3 4 78.89 100 100 0.0079 18 0.0425 0.77 0.097 0.021
4 5 55.68 100 100 0.0079 8 0.0425 0.34 0.043 0.003
5 6 53.32 100 100 0.0079 0 0.0425 0.00 0.000 0.000
1 7 63.35 100 100 0.0079 25 0.0425 1.06 0.135 0.031
7 8 138.84 100 100 0.0079 11 0.0425 0.47 0.060 0.015
9 7 185.44 100 100 0.0079 0 0.0425 0.00 0.000 0.000
2 9 87.27 100 100 0.0079 15 0.0425 0.64 0.081 0.016
Junction Table
Junction Elevation (m) Head Loss (m) HGL Pressure (m) Residual Pressure (m)
R1 19.00 - 60.85 41.85 Meets SEQ Code Minimum 22m
1 17.00 0.051 60.80 43.80 Meets SEQ Code Minimum 22m
Table 11. Process of head loss calculation using Hazen-Williams equation
Table 12. Calculating residual pressure using previous head loss

Development B-Fire Flow Conditions
Pipeline Table
From
Junction
To
Junction
Length (m)
2/3 PH Pipe flow Fire flow Pipe flow Total Pipe flow Velocity
(m/s)
Head Loss
(m)Demand (L/s) Demand (L/s) Demand (L/s)
R1 1 79.889 2.38 15 17.38 0.984 0.955
1 2 26.134 1.28 15 16.28 0.921 0.276
2 3 71.494 0.85 15 15.85 2.018 5.190
3 4 78.887 0.51 15 15.51 1.975 5.501
4 5 55.679 0.23 15 15.23 1.939 3.752
5 6 53.323 0.00 15 15.00 1.910 3.495
1 7 63.350 0.71 15 15.71 2.000 4.523
7 8 138.836 0.31 15 15.31 1.950 9.454
9 7 185.444 0.00 15 15.00 1.910 12.156
2 9 87.266 0.43 15 15.43 1.964 6.024
Junction Table
Junction Elevation (m) Head Loss (m) HGL Pressure (m) Residual Pressure (m)
R1 19.00 - 71.76 52.76 Meets SEQ Code Minimum 12m

Fire Flow Conditions Table
From Junction To Junction Pipe Area (m^2)
Maximum Allowable Maximum Total Pipe Flow
Pipe Velocity (m/s) Pipe Flow (L/s) Demand (L/s)
R1 1 0.0177 2.5 44.25 17.38
1 2 0.0177 2.5 44.25 16.28
2 3 0.0177 2.5 44.25 15.85
3 4 0.0079 2.5 19.75 15.51
4 5 0.0079 2.5 19.75 15.23
5 6 0.0079 2.5 19.75 15.00
1 7 0.0079 2.5 19.75 15.71
7 8 0.0079 2.5 19.75 15.31
7 9 0.0079 2.5 19.75 15.00
2 9 0.0079 2.5 19.75 15.43
Table 15 indicates the demand flow rate during a fire flow event, which is the highest it will reach compared to the maximum possible pipe flow
using a maximum velocity of 2.5 m/s. It illustrates that there is more than enough pressure in the network to service a fire flow scenario.
Table 15. Comparing maximum flow with total flow demand

Development A-Regular Conditions
Pipeline Table
From
Junction
To
Junction
Length
(m)
Roughness
C
Pipe Diameter Pipe Area Demand Demand PH Pipe Flow Velocity
(m/s)
Head
Loss (m)(mm) (m^2) (Lots) (L/ET/s) Demand (L/s)
Precinct 1
R2 1 79.92 100 150 0.0177 166 0.0425 7.06 0.399 0.180
PJ 2 38.60 100 150 0.0177 15 0.0425 0.64 0.036 0.001
PJ 3 72.26 100 100 0.0079 82 0.0425 3.49 0.444 0.317
3 4 87.32 100 100 0.0079 28 0.0425 1.19 0.152 0.052
PJ 5 74.23 100 100 0.0079 7 0.0425 0.30 0.038 0.003
Precinct 2
R3 1 35.85 100 150 0.0177 244 0.0425 10.37 0.587 0.165
PJ 2 76.85 100 150 0.0177 159 0.0425 6.76 0.382 0.160
2 3 92.19 100 100 0.0079 88 0.0425 3.74 0.476 0.461
PJ 4 83.78 100 100 0.0079 42 0.0425 1.79 0.227 0.107
PJ 5 72.18 100 100 0.0079 31 0.0425 1.32 0.168 0.052
Precinct 3
R4 1 43.33 100 150 0.0177 231 0.0425 9.82 0.556 0.180
PJ 2 83.00 100 150 0.0177 106 0.0425 4.51 0.255 0.081
PJ 3 60.04 100 150 0.0177 45 0.0425 1.91 0.108 0.012
PJ 4 72.24 100 150 0.0177 65 0.0425 2.76 0.156 0.029
PJ 5 104.58 100 150 0.0177 12 0.0425 0.51 0.029 0.002
(PJ= Previous Junction)

Junction Table
Junction Elevation (m) Head Loss (m)
HGL Pressure
(m)
Residual Pressure
(m)
Precinct 1
Precinct 2
Precinct 3

Development A-Fire Flow Conditions
Pipeline Table
From
Junction
To
Junction
Length (m)
2/3 PH Pipeflow Fire flow Pipe flow Total Pipe flow Velocity
(m/s)
Head Loss
(m)Demand (L/s) Demand (L/s) Demand (L/s)
Precinct 1
R2 1 79.92 4.71 15 19.71 1.115 1.20
PJ 2 38.60 0.43 15 15.43 0.873 0.37
PJ 3 72.26 2.33 15 17.33 2.206 6.18
3 4 87.32 0.79 15 17.79 2.011 6.30
PJ 5 74.23 0.2 15 15.2 1.935 4.99
Precinct 2
R3 1 35.85 6.91 15 21.91 1.222 0.641
PJ 2 76.85 4.51 15 19.51 1.104 1.137
2 3 92.19 2.49 15 17.49 2.227 8.034
PJ 4 83.78 1.19 15 16.19 2.061 6.326
PJ 5 72.18 0.88 15 15.88 2.022 5.257
Precinct 3
R4 1 43.33 6.55 15 21.55 1.235 0.790
PJ 2 83.00 3.01 15 18.01 1.019 1.059
PJ 3 60.04 1.27 15 16.27 0.921 0.635
PJ 4 72.24 1.84 15 16.84 0.953 0.814
PJ 5 83.63 0.85 15 15.85 0.897 0.842
Table 18. Process of head loss calculation using Hazen-Williams
equation

Junction Table
Junction Elevation (m) Head Loss (m)
HGL Pressure
(m)
Residual Pressure
(m)
Precinct 1
Precinct 2
Precinct 3

Fire Flow Conditions Table
From Junction To Junction
Pipe Area
(m^2)
Maximum Allowable Maximum Total Pipe Flow
Pipe Velocity (m/s) Pipe Flow (L/s) Demand (L/s)
Precinct 1
R2 1 0.0177 2.5 44.25 19.71
PJ 2 0.0177 2.5 44.25 15.43
PJ 3 0.0079 2.5 19.75 17.33
3 4 0.0079 2.5 19.75 17.79
PJ 5 0.0079 2.5 19.75 15.2
Precinct 2
R3 1 0.0177 2.5 44.25 21.91
PJ 2 0.0177 2.5 44.25 19.51
2 3 0.0079 2.5 19.75 17.49
PJ 4 0.0079 2.5 19.75 16.19
PJ 5 0.0079 2.5 19.75 15.88
Precinct 3
R4 1 0.0177 2.5 44.25 21.55
PJ 2 0.0177 2.5 44.25 18.01
PJ 3 0.0177 2.5 44.25 16.27
PJ 4 0.0177 2.5 44.25 16.84
PJ 5 0.0177 2.5 44.25 15.85
Table 20. Comparing maximum flow with total flow demand

4.2.2 Discussion
First principles essentially is a straight forward process of calculations, but when analysing
over 90 different pipe sections which create a water supply network, as in Development A, the
process can become quite time consuming and confusing. Significant research had to be
undertaken to determine the method to be used, which calculations were required and what
outputs had to be found. The standards provide several parameters which must be met, as well
as providing parameters to be used in calculations.
When creating the initial model it was difficult to create adequate catchments which were up
to standard, which meant it has to be re drawn. Catchments need to be as square or rectangular
as possible between 4 and 16 lots, while keeping them consistent as demonstrated in figure 4
above. By using Development B as a practice or example zone, it allowed the development of
the method and process that would be required for a much larger zone such as Development
A.
It was quickly apparent separate tables would have to be created for junctions and pipes, one
used for calculating head loss and one for calculating residual pressure. The major factor used
in the design of water supply networks is residual pressure, other variables such as velocity
are important, but a system will fail if the pressure is too high or too low. Once the network
was drawn on AutoCAD, each junction was numbered for analysis, which allowed the
process to advance much quicker and smoother than it otherwise would have.
To not create a difficult and confusing situation, a single reservoir per area or precinct was
used for analysis. As all pipes gain their pressure from existing council water main connection
points, if there are more than one then additional pressure will enter a system from another
location and further increase pressures. This is difficult to calculate and determine where they
meet and how this will affect flow directions and pressures.
In a fire flow scenario each junction is independently analysed with a demand of 15 L/s, with
the rest of the network under 2/3 of its regular peak hour demand. Under first principles it was
assumed the fire flow demand travelled through a single direct line of pipes to reach the
junction point, but in reality this flow would divide between the respective pipe sections
which lead to the demand junction. As seen with Development B between junction 2 and 6,
because it is a dead-end pipe the full flow demand must completely travel through a single
pipe length. This produces much larger head losses and velocities than when compared with
the same flow dividing through multiple pipe sections.

4.3 H20Map Analysis
H20Map and its method of use is part of the major focus of this report and a detailed
procedure of how to create a working water supply model will be discussed. H20Map uses the
same inputs as is used in first principles to determine certain outputs. There are many useful
functions within H20Map, especially towards reducing the time it takes to analyse a large
subdivision such as Development A.
The process begins with AutoCAD, each pipe section connecting to a junction must be a
separate line, following this each polyline layer is saved to a separate AutoCAD file,
including contours and converted into a shape file, which is read by H20Map. This is then
used to input into H20Map as polylines. The software has functions that are able to convert
polylines into pipes and junctions, forming a water supply network. There is also an
‘Elevation Interpolation’ function used to read the values of the contours at the location of
each junction. Connection points (reservoirs) need to be manually input and connected to the
network.
All relevant information is required to be entered into a window for each junction and pipe
related to calculations such as Hazen-Williams equation, as shown in figure 7 and 8:
Figure 8. Junction Attribute Browser
(H20Map, 2011)
Figure 7. Pipe Attribute Browser
(H20Map, 2011)

The ‘Demand1’ value used for each junction is the number of lots within each catchment,
allocated to the junction within the respective catchment. A zone and description is required
to be input for each junction, pipe and reservoir, so they are able to be grouped for analysis.
Junctions, pipes and reservoirs are grouped within a precinct or zone using data base queries,
which are used to create scenarios for analysis. Following this, a ‘query set’ is created to
group pipes, junctions and reservoirs for a scenario.
Figure 9 shows the process of how a ‘DB Query’ is created using code.
The previously calculated demand pattern of 0.0425 L/ET/s must be input into the software
and placed in the ‘Pattern1’ section of the junction attribute browser as shown in figure 8
above. This demand pattern is entered in the ‘Pattern’ window with a description explaining
where it has come from. Using the DB Editor, which is a window displaying all junctions or
pipes with their corresponding data, allows the demand pattern to be copy and pasted to all
junctions quickly.
Figure 10 shows the display input for creating a pattern to be used with junction lot demands.
Figure 9. Precinct 2, Pipe DB Query
(H20Map, 2011)

Simulations must be created for base (regular) conditions and fire flow conditions, which is
where the 2/3 PH demand will be input under the ‘Demand’ tab. In this window, Hazen-
Williams equation, flow units and pressure units will be set.
Figure 10. Pattern Input Menu
(H20Map, 2011)
Figure 11. Simulation Options Menu
(H20Map, 2011)

The ‘Scenario Explorer’ is used to create a simulation for each regular and fire flow situation.
A base (regular) case is used as the main scenario and a ‘child’ scenario is created off this for
fire flow. The ‘Query Set’ which the scenario will be run for is selected as well as the
simulation option.
Figure 12 shows the main page of the scenario explorer used to create all different sets of
scenarios for Development A and B.
Firstly the appropriate scenario must be selected on the main H20Map screen before using the
run manager to execute a model. The ‘Run Manager’ is where all scenarios are run to create a
model, once set up a base case or fire flow scenario can be run. Under ‘Multi-Fire flow’ the
fire flow demand of 15 L/s is set for all the corresponding junctions to be analysed, in the case
of this report all are analysed. When running a fire flow scenario model, the fire flow
simulation option must be selected before entering the fire flow window. The residual
pressure entered is the minimum pressure allowed in the system, in this case 12m. Also a
maximum velocity constraint of 2.5 m/s is entered.
Figure 12. Scenario Explorer Menu
(H20Map, 2011)
Figure 13 demonstrates the standard (base) flow conditions, whereas figure 14 shows the
fire flow window where a fire flow scenario is to be run from.

Figure 14. Run Manager, Fire flow
(H20Map, 2011)
Figure 13. Run-Manager, Main Page
(H20Map, 2011)

4.3.1 Results
H20Map Pipe/ Junction Network Output
Figure 15. H20Map Pipe/ Junction Network (Adapted from H20Map)

Development B-Regular Conditions
Junction/ Pipeline Table
Junction Demand (Lots)
Demand
(L/ET/s)
Velocity
(m/s)
Elevation
(m)
Head Loss
(m)
HGL Pressure
(m)
Residual Pressure
(m)
1 14 0.0425 0.20 16.99 0.05 60.80 43.81
2 0 0.0425 0.11 16.74 0.01 60.79 44.05
3 12 0.0425 0.07 13.49 0.01 60.79 47.30
4 10 0.0425 0.10 13.06 0.02 60.77 47.71
5 8 0.0425 0.04 10.16 0.00 60.76 50.60
6 0 0.0425 0.00 9.34 0.00 60.76 51.42
7 14 0.0425 0.13 14.55 0.03 60.77 46.23
8 11 0.0425 0.06 11.66 0.01 60.76 49.10
9 15 0.0425 0.09 11.95 0.02 60.77 48.82
Development B-Fire Flow Conditions
Junction Table
Junction Static Demand (L/s) (2/3 PH) Fire Flow Demand (L/s) Total Demand (L/s) Residual Pressure (m)
1 0.39 15 15.39 53.81
2 0.00 15 15.00 53.82
3 0.34 15 15.34 56.36
4 0.28 15 15.28 51.28
5 0.22 15 15.22 50.42
6 0.00 15 15.00 47.74
7 0.39 15 15.39 53.94
8 0.31 15 15.31 47.37
9 0.42 15 15.42 56.09
Table 21. H20Map Regular Conditions Output
Table 22. H20Map Fire Flow Conditions Output

Demand
(L/ET/s)
Velocity
(m/s)
Elevation
(m)
Head Loss
(m)
HGL Pressure
(m)
Residual Pressure
(m)
Precinct 1
1 13 0.0425 0.39 14.68 0.13 56.68 42.00
2 15 0.0425 0.04 15.75 0.00 56.67 40.92
3 10 0.0425 0.33 14.94 0.19 55.81 40.87
4 12 0.0425 0.13 10.50 0.04 55.77 45.27
5 7 0.0425 0.08 9.50 0.01 55.76 46.26
Precinct 2
1 12 0.0425 0.59 27.78 0.17 55.29 27.51
2 14 0.0425 0.26 19.17 0.08 55.06 35.89
3 11 0.0425 0.24 14.45 0.13 54.92 40.47
4 12 0.0425 0.21 16.12 0.09 54.82 38.70
5 11 0.0425 0.05 9.00 0.01 54.75 45.75
Precinct 3
1 10 0.0425 0.56 24.77 0.19 55.30 30.53
2 10 0.0425 0.25 24.52 0.08 54.61 30.09
3 7 0.0425 0.09 21.12 0.01 54.68 33.56
4 12 0.0425 0.07 26.84 0.01 54.59 27.75
5 10 0.0425 0.05 20.29 0.00 54.58 34.29
Table 23. H20Map Regular Conditions Output

Junction Table
Precinct 1
1 0.36 15 15.36 52.78
2 0.42 15 15.42 50.57
3 0.28 15 15.28 42.41
4 0.34 15 15.34 45.17
5 0.20 15 15.20 45.22
Precinct 2
1 0.34 15 15.34 38.23
2 0.39 15 15.39 45.22
3 0.31 15 15.31 46.98
4 0.34 15 15.34 45.74
5 0.31 15 15.31 50.45
Precinct 3
1 0.28 15 15.28 40.99
2 0.28 15 15.28 36.44
3 0.20 15 15.20 39.65
4 0.34 15 15.34 33.34
5 0.28 15 15.28 39.86
Table 24. H20Map Fire Flow Conditions Output

4.3.2 Discussion
H20Map is quite a large and complex software package and to learn how to use it required
significant time and effort. There is little information on the software readily available
because it is so specialised and a license is costly. This made it difficult to research or study,
but once the process and functions were created, it was quick and easy to generate models.
This software is set up so that a user only has to establish the basic information and
requirements, from which the software will do all calculations, processes and run the models
as created.
It is detailed software because of the way it takes inputs and uses them to create outputs, as
explained above in the process of creating a H20Map model. The manner in which it displays
results after running a model is clear and easy to understand, by utilising tables. Once a
demand pattern is entered and the demand lots for each catchment are entered, the program
automatically calculates the demands per catchment and accumulates the flow rate through
the system.
H20Map is American software, therefore sets the Imperial measurement system
automatically. When creating a new model you are able to change from Imperial to Metric
units, otherwise all outputs will have incorrect units. Within the software you can change
calculation units, but not output units.
The software runs independent fire flow scenarios for every junction, by selecting the
junctions required and entering the fire flow demand. This greatly reduces time in creating
models and calculations. However once a fire flow scenario is run, only relevant outputs for
junctions are displayed, such as the available flow and residual pressure. Essentially this is all
that is required, however for the purpose of comparing methods it isn’t as helpful as having
other parameters which are displayed for regular flow conditions.
The software is very efficient with creating and running models for large subdivisions such as
Development A, such that the process for creating the Development A model didn’t require
much more time or effort when compared with the Development B model.

4.4 EPANET Analysis
The results of EPANET are very important for the purpose of comparing with H20Map
results and reinforcing the validity of H20Map, where first principles might otherwise not be
as accurate.
An AutoCAD pipe and junction network is highlighted and exported as a metafile, which is
the file type recognised by EPANET. This file is loaded as a backdrop within the software,
using this backdrop, dimensions need to be set. This is done by turning ‘Auto-Length’ on and
drawing a line of known length, then determining the ratio between actual length and the
current software dimensions. The entire network must be manually drawn over the backdrop,
where all pipes will be the correct length in metres.
As in H20Map there are pipe and junction attribute browsers were all necessary information
must be entered, including elevations, as shown in figure 16 and 17:
Similar to first principles all junction demands are required to be manually calculated and
entered for each catchment as ‘Base Demand’. When conducting fire flow a demand
multiplier can be used, this dramatically reduces time in re-entering demand values.
Under ‘Project Defaults’ , all hydraulic properties are set such as flow units, Hazen-Williams
equation and many other aspects very similar to H20Map.
(EPANET, 2008)
(EPANET, 2008)

Figure 18 shows the default set up window where all major settings are input.
Fire flow demands are required to be manually input on each junction for each fire flow
scenario, which means if you have a large sub division and want to analyse each junction, it
will take some time. Because there is a demand multiplier of 0.66 the base demand needs to
be correct that when it is multiplied by 0.66 it has a value of 15 L/s + 2/3 of base demand.
Because of this it would be easier to only assess the most critical locations which are the
junctions furthest away and of the highest elevations, as they produce the lowest pressures.
A different file is used for fire flow and regular conditions for more efficient analysis of
models. Once these are set up, the scenario model can be run. Results can be viewed by either
creating a table or clicking on a specific pipe or junction.
Figure 18. Project Defaults
(EPANET, 2008)

4.4.1 Results
EPANET Pipe/ Junction Network Output
Figure 19. EPANET Pipe/ Junction Network (Adapted from EPANET)

Developement B-Regular Conditions
Junction Demand (Lots) Demand (L/ET/s) Velocity (m/s) Elevation (m) Head Loss (m) HGL Pressure (m) Residual Pressure (m)
1 14 0.0425 0.20 17 0.05 60.80 43.80
2 0 0.0425 0.11 16.5 0.01 60.79 44.29
3 12 0.0425 0.16 13.5 0.05 60.74 47.24
4 10 0.0425 0.10 13.00 0.02 60.72 47.72
5 8 0.0425 0.04 10.00 0.00 60.72 50.72
6 0 0.0425 0.00 9.25 0.00 60.72 51.47
7 14 0.0425 0.13 14.5 0.03 60.77 46.27
8 11 0.0425 0.06 11.5 0.01 60.76 49.26
9 15 0.0425 0.09 12.00 0.02 60.77 48.77
Developement B-Fire Flow Conditions
Junction Table
1 0.40 15 15.40 53.81
2 0.00 15 15.00 54.07
3 0.34 15 15.34 56.35
4 0.29 15 15.29 51.36
5 0.23 15 15.23 50.62
6 0.00 15 15.00 47.89
7 0.40 15 15.40 54.00
8 0.31 15 15.31 47.50
9 0.42 15 15.42 56.05
Table 25. EPANET Regular Conditions Output
Table 26. EPANET Fire Flow Conditions Output

Demand
(L/ET/s)
Velocity
(m/s)
Elevation
(m)
Head Loss
(m)
HGL Pressure
(m)
Residual Pressure
(m)
Precinct 1
1 13 0.0425 0.38 14.75 0.11 56.68 41.93
2 15 0.0425 0.04 15.75 0.00 56.67 40.92
3 10 0.0425 0.33 15.00 0.18 55.84 40.84
4 12 0.0425 0.13 10.50 0.04 55.81 45.31
5 7 0.0425 0.08 9.50 0.01 55.79 46.29
Precinct 2
1 12 0.0425 0.59 27.50 0.16 55.30 27.80
2 14 0.0425 0.27 19.00 0.08 55.04 36.04
3 11 0.0425 0.26 14.50 0.14 54.90 40.40
4 12 0.0425 0.21 16.00 0.08 54.77 38.77
5 11 0.0425 0.06 9.00 0.01 54.70 45.70
Precinct 3
1 10 0.0425 0.56 25.00 0.18 55.31 30.31
2 10 0.0425 0.25 24.50 0.08 54.62 30.12
3 7 0.0425 0.09 21.00 0.01 54.68 33.68
4 12 0.0425 0.07 27.00 0.01 54.59 27.59
5 10 0.0425 0.05 20.50 0.01 54.59 34.09
Table 27. EPANET Regular Conditions Output

Junction Table
Precinct 1
1 0.36 15 15.36 52.71
2 0.42 15 15.42 50.58
3 0.28 15 15.28 42.35
4 0.34 15 15.34 45.17
5 0.20 15 15.20 45.20
Precinct 2
1 0.34 15 15.34 38.55
2 0.39 15 15.39 45.42
3 0.31 15 15.31 46.96
4 0.34 15 15.34 45.90
5 0.31 15 15.31 50.48
Precinct 3
1 0.28 15 15.28 40.79
2 0.28 15 15.28 36.49
3 0.20 15 15.20 39.81
4 0.34 15 15.34 33.22
5 0.28 15 15.28 39.69
Table 28. EPANET Fire Flow Conditions Output

4.4.2 Discussion
Compared with H20Map, EPANET is far easier to learn and understand, as well as having far
more information available when researching the software. However because it is easier to set
up a model, it is far more time consuming due to EPANET being quite manual input intensive
freeware. The largest problem experienced when using this software was getting the software
to read the correct pipe lengths when drawn. After researching and trial and error, it was
found the auto-length function needs to be set up so that once the user draws the water supply
network; the software automatically reads the accurate length in metres and enters it as a
parameter, as detailed in section 4.4.
The software is from the United States and automatically uses Imperial units, which means
the user will need to manually change the software units to Metric, which can be altered at
any point during a model. Demand for each junction is required to be manually calculated and
entered as an inflow for each junction within EPANET. Once a model is run the freeware will
automatically accumulate the flow through the network.
A disadvantage or negative point about EPANET is its fire flow analysis capabilities, which
have to be manually input by the user. This involves entering the 2/3 PH demand with the 15
L/s for each junction separately, every time changing the inflows back to what they were. A
slight advantage to this method though, is that the output results are presented the same as
regular conditions and are easily comparable with many more parameters.
Based on the fact the software is free, it is quite capable of performing a water supply network
analysis, but in a simpler manner than H20Map.

4.5 Water Supply Network Analysis and Comparison
The purpose for analysing and comparing 3 water supply network design methods is to
reinforce the use of H20Map as the industry standard and required software. Comparing the
regular conditions of Development B between the three methods produced the same results
except for a few variations due to slight differences in elevation. This is because the elevation
used in first principles comes from manual readings in AutoCAD whereas H20Map
interpolates between contour lines to read exact elevations and EPANET uses manual
elevation inputs from first principles.
Due to the small size of Development B it was an ideal area to test the methods of fire flow
analysis. It was found that through first principles the added fire flow is assumed to travel on
a direct path towards the demand junction, which creates large head losses through those
pipes, but rather it was found that where it was possible, this flow would uniformly split up
between pipes to meet up at the demand junction, which reduces head losses significantly.
As shown in figure 6, from junction 2-6 of Development B, it is a single pipe section leading
to a dead end, therefore the entire flow rate is forced to travel down, producing large head
losses and dramatically larger pressure loses. But when a fire flow situation is placed at either
junction 7 or 9, the flow rate divides between two pipelines in an effort to reach the demand
junction more efficiently. The fire flow results for first principles, H20Map and EPANET
through junction 2-6 are the same, with the only exception being slight elevation variances.
First principles residual pressure is lower with a value of 51.78m and 52.50m at junction 7
and 9 of Development B when compared with H20Map and EPANET with values at 54.00m
and 56.05m, due to the above reasons. All methods produced adequate results in accordance
with the standards set by the governing bodies.
These principles are shown more dramatically in Development A where pipes sections are
much further from reservoirs than in Development B. The residual pressure under normal
conditions for EPANET and first principles is very close together, less than 1%, which is
likely due to rounding of figures within calculations in the software. The main difference
between H20Map values and the other two methods is the difference in elevation, as was
expected.

Values for velocity and head loss were expected to be marginally dissimilar due to the
different methods of design being used because of rounding values in calculations and due to
slight variances in lengths and elevations. It was found velocity and head loss values were the
same and others very near, while under regular flow conditions.
As seen previously in Development B, the method in which fire flow is analysed by first
principles is different to H20Map and EPANET. This is due to the fact that it would be too
difficult to determine how much flow will travel through certain pipes to reach a demand
junction. The first initial junctions in each precinct throughout Development A have the same
residual pressures with the exception of slight elevation differences. Which means the first
principles process was correct up until a certain point. At this point both software continue to
create consistent output. This further proves H20Map and EPANET produce the same results
and are more accurate than first principles. As previously discussed in the introduction to this
report, EPCM Group Consulting used the same method through EPANET to produce water
supply outputs and produced equivalent outcomes (EPCM, 2011).
When calculating fire flow by first principles, there are large head losses and overall the
pressure drops dramatically through the system. Although in reality this is not the case, such
as with precinct 2, the pressure past junction 4 and 5 falls below 12m according to first
principles. This meant a 150mm pipe had to be used connecting off junction 1 for a large
enough pressure to reach the end. When the same model was run using software the pressure
was far from critical because of lower head losses.
First principles produces adequate results, in terms of meeting the design parameters, but part
of the fire flow calculation process isn’t accurate, along with being quite time consuming,
making it a less desirable method compared with H20Map and EPANET. Calculated using
first principles, for the purpose of understanding how the conditions change in a fire flow
scenario, it is clear that velocity and head loss dramatically increase. Residual pressure drops
further due to the increase in head loss while the hydraulic grade line provided by council is
much higher in a fire flow situation and the required minimum pressure is 10m lower than
normal conditions. All these aspects allow for pressure to drop far more and still be
considered acceptable.

5 SEWERAGE NETWORK ANALYSIS
5.1 Initial Calculations and Information
Gravity sewer network analysis involves investigating a network of pipes for specific design
parameters, set by the respective governing bodies. These parameters include flow demand,
velocity and depth of flow. In a gravity sewer, flow accumulates as it travels downward
toward a connection point. Flow rates, velocity and depths increase the closer the flow is to
the outlet, due to having a larger flow rate and less of a slope. SEQ Code details the maximum
depth of flow at any point is 75% of the depth of the pipe.
Development A and Development B had to be divided into 5 catchments, as shown in figure
20 below, due to the way in which the land falls. Once the model has been set up, demand
patterns are required to be calculated using SEQ Code specifications. Peak Wet Weather Flow
(PWWF) is the major design parameter in determining the demand pattern per lot or
equivalent tenement (ET). All demand calculations are based off average dry weather flow
(ADWF) and is given in table 10 of the SEQ Code and the EP/ET conversion is located in
Appendix A of the same document.
For the purpose of this project it was decided to assess 15 pipe sections for the main
Development A section. This is just as effective as assessing all junctions but will create a
less confusing scenario to understand, as the entire sections of junctions are displayed in the
appendix of this report.
A table is created to calculate the ADWF in L/ET/d to be used latter on, in calculating the
PWWF demand pattern.
Sewerage Demand Table
ADWF 180 L/EP/d (SEQ Code - Table 10)
EP/ET 2.73 (SEQ Code - Appendix A)
ET 628 Lots Development A
ET 95 Lots Development B
ADWF 491.4 L/ET/d (EP/ET) X ADWF (L/EP/d)
Table 29. Table detailing sewerage demands

Table Detailing Peak Factor Demands
Demand Demand
Scenario
Peaking
Factors L/ET/d L/ET/s
ADWF N/A 491.4 0.0057
PDWF 2.39 (C2) 1174.21 0.0136
PWWF 4 1965.6 0.0228
Table 30. Table detailing sewerage demands (SEQ Code – Table 10)
Demand (L/ET/s)
ADWF – Average Dry Weather Flow
PDWF – Peak Dry Weather Flow
PWWF – Peak Wet Weather Flow
, where EP = ET = 628
PWWF demand is 0.0228 L/ET/s which is the demand pattern used in first principles
calculations and design software. It is the maximum demand that can possibly be produced
under regular peak conditions.
Manning’s Equation was introduced by Irish Engineer Robert Manning in 1889 as an
alternative to the Chezy Equation. The equation applies to uniform or steady flow in open
channels (FishXing, 2006). It is a more efficient and less complicated method for calculating
channel flow when compared with the Chezy Equation.
Manning’s Equation for gravity channel flow:
(SEQ Code, P.29)
Where:
V = velocity in m/s
n = Manning’s roughness coefficient (0.0128)
= hydraulic radius in metres
S = slope
A = area of flow in
P = wetted perimeter in metres

5.2 First Principles Analysis
Gravity sewer networks use minimum grades to develop enough velocity in specific pipe
diameters, as to not have any build ups or blockages occur. Flow accumulates through a
system, ultimately reaching a connection point, such as a trunk sewer, as is the case in this
project. The flow demand is determined by multiplying the above demand pattern with the
number of lots within a specific pipe section.
The invert height of a pipe at any point is the elevation at the bottom of the pipe. Depending
on the bend angle and whether or not pipes are meeting, manholes also require a certain
benching and drop, but for the purpose of this project that was not required to be taken into
account, as the purpose is to analyse a sewerage pipeline network.
First a table was prepared to calculate the invert height of each junction, which is either the
beginning or end of a pipe, to be use in the slope calculation. GCCC Land Development
Guidelines specify a minimum depth for certain pipe sizes in specific locations as shown in
table 6 of this report. There are cases where a pipe would otherwise be travelling in an upward
direction, meaning a manhole would have to be deeper to create a downward gravity flow.
Often these situations are dealt with on a case by case basis.
From this a table is created to calculate the maximum possible velocity and flow through each
section of pipe using manning’s equation, flowing at 3/4 depth as specified by SEQ Code.
This was done to confirm that with a worst possible case the velocity would not exceed 3 m/s
as stated in the SEQ Code and shown in section 2.3.2 of this report. It was also completed to
assess whether the maximum possible flow rate could accommodate the worst case scenario
flow rate. Following this a table was created to calculate actual flow rates based off the peak
wet weather flow and the number of lots located on each pipe section. To calculate the depth,
velocity, wetted area and perimeter of this flow, a series of equations had to be used based off
fluid mechanics.
The sewerage network was designed as a whole, working together, to flow toward the same
discharge points as opposed to designing by each precinct. Throughout this process locations
of pipes and their slopes changed, as part of the optimisation process. The minimum usable
pipe size is 150mm diameter as shown in section 2.4.2. This pipe requires minimum grades
for different situations, shown in table 4, so that adequate velocity and flow is created and
minimal opportunity for blockages to occur.

A trial and error method is undertaken using a known slope, an angle in radians can be
guessed to match the known flow rate, which will then be used to determine the
corresponding, flow depth and velocity. Velocity is calculated by dividing the known flow
rate by the calculated area.
Pipe Flow Less Than Half Full Pipe Flow More Than Half Full
( ) ( )
Where:
A = area of flow in
P = wetted perimeter in metres
D = flow depth in metres
r = radius in metres
θ = angle in radians
To find the angle in radians for flow depth at 3/4 full:
Where:
θ = Angle in radians
r = Radius of pipe in metres
h= Height that is not submerged in metres
Table 31. Table detailing equations to find area, wetted perimeter and flow depth
(Bengtson, H.H, 2014) (Clayton, T. C., 2009)
(Bengtson, H.H, 2014)

5.2.1 Results
Development B and Development A Junction and Pipe Layout
Figure 20. Numbered pipe sections assessed as part of results (Adapted from AutoCAD)

Invert Height for Start and End of Pipe Section
Pipeline Table
Pipe Section
Upstream
Elevation (m)
Upstream
Invert (m)
Downstream
Elevation (m)
Downstream
Invert (m)
Precinct 1
1 15.75 9.2 11.5 10.45
2 10.25 10.45 6.25 5.2
3 14.25 13.5 6.25 5.2
4 15 14.4 7 6.25
5 6.25 5.2 4 2.75
Precinct 2
1 28.75 28 19.5 18.45
2 27 26.25 23.5 22.75
3 16.75 12.75 10 7.35
4 7.25 6.2 4 2.75
5 4.75 3.35 4 2.75
Precinct 3
1 25.5 24.1 24.75 23.9
2 27 26.4 24 23.25
3 19.5 18.45 19 17.95
4 24.5 23.6 15.5 14.75
5 21 19.5 13.5 12.45
Table 32. Start and End junction invert heights of particular pipe sections

Maximum Flow (3/4 Full Pipe) – Development A
Manning's Equation for 3/4 Full Pipe
Pipe
Section
Pipe Diameter
(mm)
Theta
(radians) Area m^2) Perimeter (m)
Hydraulic
Radius (m)
Slope
(Grade) Velocity (m/s) Flow Rate (L/s)
Precinct 1
1 150
2.0944 0.01422 0.31416 0.04525 0.0339 1.826 25.955
2 150
2.0944 0.01422 0.31416 0.04525 0.0295 1.705 24.238
3 150
2.0944 0.01422 0.31416 0.04525 0.0409 2.006 28.513
4 150
2.0944 0.01422 0.31416 0.04525 0.0502 2.222 31.587
5 150
2.0944 0.01422 0.31416 0.04525 0.0168 1.286 18.282
Precinct 2
1 150
2.0944 0.01422 0.31416 0.04525 0.0652 2.533 36.017
2 150
2.0944 0.01422 0.31416 0.04525 0.0155 1.236 17.574
3 150
2.0944 0.01422 0.31416 0.04525 0.0713 2.649 37.663
4 150
2.0944 0.01422 0.31416 0.04525 0.0319 1.772 25.185
5 150
2.0944 0.01422 0.31416 0.04525 0.0119 1.081 15.374
Precinct 3
1 150
2.0944 0.01422 0.31416 0.04525 0.0062 0.783 11.133
2 150
2.0944 0.01422 0.31416 0.04525 0.0299 1.716 24.397
3 150
2.0944 0.01422 0.31416 0.04525 0.0142 1.183 16.824
4 150
2.0944 0.01422 0.31416 0.04525 0.0407 2.002 28.457
5 150
2.0944 0.01422 0.31416 0.04525 0.0655 2.539 36.096
Table 33. Maximum possible flow rates

Manning's Flow Using PWWF- Development A
Parameters of Flow (PWWF Demand)
Pipe
Section
Pipe Diameter
(mm)
Demand
(lots)
Theta
(radians) Area (m^2) Perimeter (m)
Hydraulic
Radius (m) Flow Depth (m)
Slope
(Grade) Velocity (m/s) Flow Rate (L/s)
Precinct 1
1 150
7 0.9359
0.0004 0.0702 0.0052 0.008
0.0339
0.434 0.1596
2 150
56
1.5860 0.0016 0.1190 0.0139 0.022
0.0295
0.775 1.2768
3 150
52
1.4933 0.0014 0.1120 0.0125 0.020
0.0409
0.849 1.1856
4 150
14
1.0545 0.0005 0.0791 0.0066 0.010
0.0502
0.614 0.3192
5 150
122
2.1019 0.0035 0.1576 0.0221 0.038
0.0168
0.798 2.7816
Precinct 2
1 150
12
0.9850 0.0004 0.0739 0.0058 0.009
0.0652
0.642 0.2740
2 150
19
1.3108 0.0010 0.0983 0.0099 0.016
0.0155
0.447 0.4330
3 150
132
1.7667 0.0022 0.1325 0.0167 0.027
0.0713
1.362 3.0096
4 150
177
2.1290 0.0036 0.1597 0.0226 0.039
0.0319
1.114 4.0356
5 150
202
2.5616 0.0057 0.1921 0.0295 0.054
0.0119
0.813 4.6056
Precinct 3
1 150
14 1.3615
0.0011 0.1021 0.0106 0.017
0.0062
0.296 0.3192
2 150
9
1.0090 0.0005 0.0757 0.0060 0.009
0.0299
0.448 0.2052
3 150
14
1.2292 0.0008 0.0922 0.0088 0.014
0.0142
0.395 0.3192
4 150
133
1.6117 0.0017 0.1209 0.0143 0.023
0.0407
0.926 1.596
5 150
46
1.3652 0.0011 0.1024 0.0106 0.017
0.0655
0.965 1.0488
Table 34. Actual flow rates and parameters

5.2.2 Discussion
First principles essentially is a straight forward process of calculations, but when analysing
well over 100 different pipe sections which create a sewerage network, such as Development
A, the process can become quite time consuming and confusing. Significant research had to
be undertaken to determine the method to be used, which calculations were required and what
outputs had to be found. The standards provide several parameters which must be met, as well
as providing parameters to be used in calculations.
From the outset it was difficult to determine which direction many lots were falling or
whether they were on flat ground, which in turn made it difficult to determine the location of
pipes. With no experience in the area of designing the layout of a sewerage network, it
required significant trial and error until the final layout was produced. Due to the way the land
falls in the region of Development A and Development B, the areas were split into 5 separate
catchments or discharge points for the 2 zones.
Up until the analysis stage certain pipe locations were still changing, due to the fact that
certain properties were graded incorrectly or could be graded towards the verge rather than
the rear of the lots. Doing this would significantly reduce costs for developers in the short
term and long term as well as creating minimal hassle for home owners, because there
wouldn’t be a sewer pipeline running through their back yard. This will also ease maintenance
processes for GCCC in the long term.
Significant research was undertaken into fluid mechanics to determine the methodology and
equations to be used in the process of calculating the height, velocity, area, and perimeter of
varying flow rates of inconsistent water depths. In the process of first principles, junction and
pipeline tables were created. The junction table detailed the elevation and invert height for
each junction, whereas the first pipeline table was used to calculate the maximum velocity and
flow rate of a pipe using Manning’s equation at a fixed depth of 3/4. The second pipeline
table was created to calculate the flow demand for each pipe section using peak wet weather
flow and from this use a series of calculations to determine all the factors of Manning’s
equation to calculate flow depth and velocity.
Because of the sheer number of junctions it was decided to analyse straight sections of pipe,
making the analysis just as effective, but would cut the calculation time significantly.

5.3 EPA SWMM Analysis
The results of EPA SWMM are very important for the purpose of validating its use as gravity
sewer analysis software and comparing these results with those of first principles and
outlining the reasons behind any differences. EPA SWMM is predominantly a storm water
management model, but can model gravity sewer systems due to the principle it operates
under, which is the accumulation of flow, using manning’s equation. As each pipe section
begins and connects onto further pipes, flow accumulates. During this, flow depths and
velocities alter with the variations in slope and length of pipes.
An AutoCAD pipe and junction network is highlighted and exported as a metafile, which is
the file type recognised by EPA SWMM. This file is loaded as a backdrop within the
software, using this backdrop, dimensions need to be set. This is done by turning ‘Auto-
Length’ on and drawing a line of known length, then determining the ratio between actual
length and the current software dimensions. The entire network must be manually drawn over
the backdrop, where all pipes will be the correct length in metres, as was done in EPANET.
As in H20Map and EPANET there are pipe and junction attribute browsers were all necessary
information must be entered, including invert heights as shown in figures 21 and 22 below:
(EPA SWMM, 2005)
(EPA SWMM, 2005)

The flow demand for each pipe section is entered under ‘Inflows’ in the junction attribute
browser, the freeware automatically accumulates the flow through the system and can output
the corresponding depth, velocity, capacity and many more variables.
Under ‘Project Defaults’ , all flow properties are set such as flow units, pipe roughness for
Manning’s equation, the type of section to be used, as well as a very important factor, steady
flow routing method.
Once the model has been created, it is ready to be run using the ‘Run’ command, which will
show the percentage of flow routing, which creates a continuity error. If it has been done
correctly using steady flow, it will display 0.00% continuity error.
Figure 23. Project Defaults
(EPA SWMM, 2005)

5.3.1 Results
EPA SWMM Pipe/ Junction Network Output
Figure 24. EPA SWMM Pipe/ Junction Network (Adapted from EPA SWMM)

EPA SWMM Development A Output
Parameters of Flow (PWWF Demand)
Pipe Section Pipe Diameter (mm) Flow Depth (m) Slope (grade) Velocity (m/s) Flow Rate (L/s)
Precinct 1
1 150 0.009 0.0339 0.452 0.1596
2 150 0.024 0.0295 0.801 1.2768
3 150 0.024 0.0451 0.768 1.1856
4 150 0.011 0.0502 0.617 0.3192
5 150 0.037 0.0159 0.800 2.7816
Precinct 2
1 150 0.010 0.0654 0.668 0.274
2 150 0.017 0.0158 0.468 0.433
3 150 0.030 0.0714 1.406 3.0096
4 150 0.043 0.0319 1.142 4.0368
5 150 0.062 0.0119 0.819 4.6056
Precinct 3
1 150 0.018 0.0062 0.307 0.3192
2 150 0.010 0.0299 0.460 0.2052
3 150 0.015 0.0143 0.412 0.3192
4 150 0.025 0.0415 0.964 1.5960
5 150 0.018 0.0656 1.001 1.0490
Table 35. EPA SWMM flow rates and parameters

5.3.2 Discussion
EPA SWMM is designed to run in a similar way to EPANET because both programs are
created by US EPA This made it easier to understand, learn and develop a gravity sewer
model. Gravity sewers follow a simple principle, where sewerage flows from a higher point
down to a discharge point which in this project is a trunk sewer. As in EPANET it is quite
time consuming to set up a model, as the entire network must be drawn by hand, along will all
the inputs which must be input for each junction and pipe.
The software is from the United States and automatically uses Imperial units, which means
the user will need to manually change the software units to Metric, which can be altered at
any point during a model. The ‘Auto-Length’ function works similar to EPANET, first a
backdrop is loaded and a known length is drawn, from which a ratio between actual and
software length is made. EPA SWMM must be closed and re-opened; changing the
dimensions and turning auto length on, so all pipes that are drawn have the correct lengths.
Flow demand must be manually calculated for each pipe section, where the software will
accumulate the flow through the network, as well as calculating variables such as flow depth
and velocity of the varying flow. The first models that were run, had issues with errors in flow
routing, which meant the way which the software was calculating the accumulating flow and
its variables was with an incorrect method. After some research and attempts, it was found
that a steady flow routing option must be selected.

5.4 Sewerage Network Analysis and Comparison
The purpose of conducting a sewer analysis using EPA SWMM and first principles was to
confirm whether or not EPA SWMM could be used for gravity sewer analysis and to reinforce
the method of first principles. Five sewer networks which cover the Development A and
Development B area were analysed, but for the purpose of this report only the main
Development A section was reported and the others are placed in the appendix of this report.
All the inputs used in EPA SWMM originate from first principles, which minimises room for
any errors to occur. Based on the calculation method and using identical inputs, the flow rate
outputs for both EPA SWMM and first principles are found to be the same, as expected. The
majority of slopes calculated by hand and through software are identical, except for a few
where they are very similar. This is due to the software performing slope calculations between
each junction whereas first principles slope calculations were performed for entire straight
sections of pipe, which produces similar and accurate slope results.
Several pipe sections have a larger flow depth and velocity output from EPA SWMM than
first principle calculations. The only realistic conclusion is that the series of calculations
detailed in table 34 are slightly less accurate than EPA SWMM. This is similar enough, that it
is considered correct for the purpose of this report, due to a rough 1% difference.
In certain scenarios such as with precinct 1, pipe section 1 flow depth, slope and flow rate are
identical for both methods but the velocity in EPA SWMM is 0.018m/s larger. From an
investigation it has been determined this small variance is due to rounding numbers up within
the software which creates slightly larger outcomes, whereas Microsoft Excel uses the entire
number for an exact result. All of these circumstances contribute to small differences in
outputs; nevertheless the major output which determines the accuracy and effectives of using
these two methods is the flow rates. If these don’t match then nothing else could possibly be
correct or accurate.
First principles and EPA SWMM both produce adequate results, in terms of meeting the
design parameters, apart from a few small variances. The standards state a minimum velocity
requirement of 0.7 m/s as shown in table 3, which from the above results would appear quite

difficult to maintain. SEQ Code specifies a maximum 3m/s flow velocity, so that pipe erosion
and degradation does not occur.
Following consultation with industry professionals it was determined that it is not completely
necessary to reach this value and velocities from approximately 0.35 m/s, are adequate. Low
velocities tend to only occur at the beginning of a new pipe section; with a low number of lots
connected up, in these cases the slopes can be slightly increased to achieve a higher velocity.
Low velocities or difficult slope situations are dealt with on a case by case basis. As
previously discussed, EPCM Group Consulting used the same method through EPA SWMM
to produce sewer network outputs and produced equivalent outcomes (EPCM, 2011).

6 CONCLUSION
The purpose of this project was to undertake an investigation to find differences and
similarities between methods of first principles and design software, where conclusions will
be drawn, as to determine the viability of EPANET to be used alongside H20Map as a method
to confirm results, endorsing H20Map as appropriate industry wide standard software. As
well the viability of EPA SWMM, by comparing with first principles methods, to be used as
an analysis design tool for sewer networks has been assessed.
This was achieved by dividing the project into smaller objectives which allowed for a
thorough analysis and comparison. Analysis, comparisons and preliminary designs for water
supply and sewerage networks were completed for each section, through the use of first
principles, H20Map, EPANET and EPA SWMM. The optimisation of the networks and final
pipe sizes and network layout for the subdivisions was completed. This allowed for
clarification of theories used in the analysis of water supply and sewerage networks.
It was discovered for water supply that first principles, H20Map and EPANET use the same
methods and theories to calculate residual pressure with slight variations due to calculation
rounding and elevation. Under fire flow conditions it was found first principles is unable to
accurately calculate pressure divisions through pipe sections, whereas design software
consistently output accurate and consistent results. This proves the viability of EPANET to be
used alongside H20Map as a method for confirming and reinforcing results, further endorsing
H20Map as the industry standard software to be used.
Through the analysis and comparison of first principles with EPA SWMM, it was found
similar methods are used to accumulate inflows through the sewerage network, developing
identical flow rates. Slight variations are found when comparing flow parameters with first
principles calculations and software output, which is due to calculation rounding, as well as
different lengths and elevations used for certain slope calculations as explained in the
analysis. This proves the viability of EPA SWMM to be used as an analysis design tool for
sewerage networks.
Overall the project accomplished its objectives and overall aims.

7 REFERENCES
2011. Water Supply Code of Australia, WSA 03-2011. 3rd Edition. Sydney: Water Services
Association of Australia Limited.
2002. Sewerage Code of Australia, WSA 02-2002. 2nd Edition. Melbourne: Water Services
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2013. SEQ Water supply and Sewerage Design & Construction Code (SEQ WS&s D&C
Code), DESIGN CRITERIA. 1st Edition. SEQ Design and Construction Code.
2013. Policy 11: Land Development Guidelines - Section 4, Water Reticulation- Design
Requirements. 2005 Edition. Gold Coast City Council.
2013. Policy 11: Land Development Guidelines - Section 5, Sewer Reticulation- Design
Requirements. 2005 Edition. Gold Coast City Council.
2013. Policy 11: Land Development Guidelines – Section 1, Introduction. 2005 Edition. Gold
Coast City Council.
2011. Water Supply and Sewerage Network Analysis Report – Final Report. EPCM Group.
2014. About Us. Water Services Association of Australia. Available:
https://www.wsaa.asn.au/AboutUs/Pages/default.aspx#.U2Lq8_mSx8E
2012. Fact Sheet. SEQ Water Supply and Sewerage Design and Construction Code.
Available:http://www.seqcode.com.au/storage/SEQ%20Code%20Factsheet%201%20July%2
02013.pdf
2001. Major Loss Calculation for Water in Pipes using Hazen-Williams Friction Loss
Equation. LMNO Engineering, Research and Software Ltd. Available:
http://www.lmnoeng.com/hazenwilliams.htm

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