Detailed Design Brief: Upgrade to Lower Brown Hill...

Detailed Design Brief: Upgrade to Lower Brown Hill Creek

5th May 2014

This page was left intentionally blank.

iii

5th May 2014

Julie Mills, Faisal Ahammed

University of South Australia

Mawson Lakes SA 5095

RE: Detailed Design Brief to undertake the Detailed Design for the upgrade to Lower Brown Hill

Creek.

Dear Julie and Faisal,

Prestige Worldwide would like to formally extend their interest for the undertaking of the Detailed

Design for the upgrade to Lower Brown Hill Creek.

Having extensive experience in the field we believe we are in the ideal position to conduct the

Detailed Design and that our company will continue to deliver outstanding results are per our

proven track record. Furthermore specialising in Civil Engineering with extensive experience we are

supremely confident that a solution can be provided that exceeds all expectations.

After a thorough investigation of the required scope of the work, taking into account all

considerations and potential issues that may become apparent during the project, Prestige

Worldwide have determined that the value of the detailed Design for the upgrade to Lower Brown

Hill Creek to be:

$364,320.00 (GST included)

This value is based on an extensive review of the information provided. It is valid for a period of

three months from submission. On behalf of Prestige Worldwide, I would like to thank the clients for

the consideration of our application, and in the event that further information is required please do

not hesitate to contact us.

Yours sincerely,

Scott Lines

Project Manager

Prestige Worldwide

v

Declaration

Business Trading Name:

Prestige Worldwide Engineering

ABN:

12 34 56 789

Company Address and Phone:

Mawson Lakes Boulevard

Mawson Lakes

South Australia 5095

(08) 8302 6611

Principal Contact:

Scott Lines

Project Manager

[email protected]

Declaration Statement:

Prestige Worldwide declares this Design Brief document is accurate at the time of printing.

Scott Lines Signed:

Project Manager Date: 5th May 2014

Belinda Lee Signed:

Assistant Project Manager/ Quality Manager Date: 5th May 2014

vii

Executive Summary

This report presents the Detailed Design Brief for the Upgrade to Lower Brown Hill Creek (LBHC).

Prestige Worldwide has conducted a thorough analysis of the previously proposed culvert channel,

with the addition of various Water Sensitive and Urban Design (WSUD) technologies.

The main purpose of the proposed design is to increase the capacity of the design flow to 60m3/s,

however the addition of WSUD and recreational amenities is considered to create a positive impact

and has been explored.

The information within this report outlines the direction to be taken throughout the Detailed Design,

clarifying key issues and providing information that is directly relevant to the design in order to allow

for a smooth transition to the design phase.

The fundamental objectives of the detailed design phase include:

1. Culvert design

2. Environmental Management Plan

3. Service relocation

4. Redevelopment and maintenance of the existing creek

5. WSUD Technologies to be employed

6. Construction and operation issues

7. Detailed costing of the entire project

8. Detailed drawings of relevant aspects of the project

9. Detailed recreational amenities

10. Contract specifications

11. Construction of a company website

ix

Contents Declaration .............................................................................................................................................. v

Executive Summary ............................................................................................................................... vii

List of Tables ......................................................................................................................................... xii

List of Figures ........................................................................................................................................ xii

1 Project Description .......................................................................................................................... 1

2 Key considerations .......................................................................................................................... 2

Services ................................................................................................................................... 2 2.1

Culvert Design ......................................................................................................................... 2 2.2

Slope ................................................................................................................................ 3 2.2.1

Joint Type ........................................................................................................................ 3 2.2.2

Allowable head water and consideration ....................................................................... 3 2.2.3

Culvert inlet structure selection ..................................................................................... 4 2.2.4

Outlet flow velocities and consideration ........................................................................ 4 2.2.5

Soil cover ......................................................................................................................... 5 2.2.6

Manholes ........................................................................................................................ 5 2.2.7

Additional consideration ................................................................................................. 5 2.2.8

Recreational Amenities ........................................................................................................... 6 2.3

Wetland Design ....................................................................................................................... 7 2.4

Geotechnical considerations for Wetland design ........................................................... 8 2.4.1

Retaining Walls ....................................................................................................................... 9 2.5

Earth-retaining structures ............................................................................................. 10 2.5.1

Geotechnical Considerations ................................................................................................ 11 2.6

Subsurface conditions ................................................................................................... 11 2.6.1

Traffic Considerations ........................................................................................................... 14 2.7

Diversion of Traffic ........................................................................................................ 14 2.7.1

Routes to Access Points ................................................................................................ 14 2.7.2

x

Bike Track and Footpath ............................................................................................... 14 2.7.3

Maintenance of Creek and Culverts...................................................................................... 15 2.8

Channel Maintenance ................................................................................................... 15 2.8.1

Culvert maintenance ..................................................................................................... 16 2.8.2

Environmental Considerations .............................................................................................. 17 2.9

Water ............................................................................................................................ 17 2.9.1

Land ............................................................................................................................... 17 2.9.2

Flora and Fauna ............................................................................................................. 17 2.9.3

Air Quality ..................................................................................................................... 18 2.9.4

Noise Pollution .............................................................................................................. 18 2.9.5

Community and Heritage .............................................................................................. 18 2.9.6

Land Acquisition ............................................................................................................ 20 2.9.7

Affected Businesses ...................................................................................................... 21 2.9.8

Bus Routes ..................................................................................................................... 22 2.9.9

3 Scope for Detailed Design ............................................................................................................. 23

Deliverables ........................................................................................................................... 23 3.1

Proposed Organisation Structure ......................................................................................... 24 3.2

4 Project Schedule ........................................................................................................................... 25

5 Proposed structure breakdown .................................................................................................... 26

Project Manager.................................................................................................................... 26 5.1

Assistant Project Manager/Quality Manager ....................................................................... 26 5.2

Existing Creek ........................................................................................................................ 27 5.3

Water Team .......................................................................................................................... 29 5.4

Recreational Amenities ......................................................................................................... 29 5.5

Construction and Operation ................................................................................................. 30 5.6

Environmental Management ................................................................................................ 31 5.7

Contract Management .......................................................................................................... 31 5.8

Drawings and Website Coordination .................................................................................... 32 5.9

xi

6 Costing .......................................................................................................................................... 33

Hourly Rates .......................................................................................................................... 33 6.1

Detailed Cost Proposal .......................................................................................................... 34 6.2

7 References .................................................................................................................................... 35

8 Appendices .................................................................................................................................... 36

Appendix A – Wetland Design Checklists .......................................................................................... 36

Appendix B – Culvert Maintenance Checklist ................................................................................... 41

Appendix C – Gantt Chart ................................................................................................................. 42

xii

List of Tables

Table 1 - Soil type and groundwater level for Wetland locations. ......................................................... 8

Table 2 - Proposed sites for earth-retaining structures ........................................................................ 10

Table 3 - Current soil conditions ........................................................................................................... 11

Table 4 - Current soil conditions continued .......................................................................................... 12

Table 5 - Slope details ........................................................................................................................... 13

Table 6 - Key Dates of Project ............................................................................................................... 25

Table 7 - Hourly Rates ........................................................................................................................... 33

Table 8 - Detailed Cost Proposal ........................................................................................................... 34

List of Figures

Figure 1 - Culvert and Wetland Location Map (Tonkin Consulting 2014) ............................................... 1

Figure 2 - Visual illustration of the traffic soil loads on the culverts ...................................................... 2

Figure 3 - Culvert Inlet (Worley Parsons, 2001) ...................................................................................... 4

Figure 4 - Identification of locations of amenity along track/path route (Adapted from Google Maps

2014) ....................................................................................................................................................... 6

Figure 5 - Location of Open Spaces and the Grassmere Reserve (Adapted from Google Maps 2014) .. 6

Figure 6 - Wetland Layout (Melbourne Water 2010) ............................................................................. 7

Figure 7 - Gabion basket retaining wall (Riverdale 2011) ....................................................................... 9

Figure 8 - Example of area that may require maintenance .................................................................. 15

Figure 9 - Heritage Sites along LBHC (Adapted from Tonkin Consulting 2014) .................................... 19

Figure 10 - Affected businesses (Adapted from Tonkin Consulting 2014) ........................................... 21

Figure 11 - Bus routes within the area of the map (Adapted from Tonkin Consulting 2014) .............. 22

Figure 12 - Proposed Management Structure ...................................................................................... 24

Figure 13 - Wetland Calculation Checklist ............................................................................................ 36

Figure 14 - Wetland Assessment Checklist ........................................................................................... 37

Figure 15 - Construction Inspection Checklist ...................................................................................... 38

Figure 16 - Asset Handover Checklist .................................................................................................... 39

Figure 17 - Wetland Maintenance Checklist ......................................................................................... 40

Figure 18 - Culvert Checklist (Worley Parsons, 2001) ........................................................................... 41

1

1 Project Description

The Detailed Design is to focus on solving the issue of flooding along LBHC, located between the

confluence of Keswick Creek and ANZAC highway. In order to protect the adjacent properties and

achieve the goal of 60m3/s flow rate along the LBHC catchment the use of two parallel culverts in

addition with the existing channel is considered the optimal solution. This section of the creek is

approximately 3298.8m long and contains 7 vehicular bridges and 4 pedestrian bridges to consider in

the design. Additionally several large arterial roads (South Road and Marion Road) cross both the

proposed culvert route as well as the creek and the effect this will have on the design needs to be

carefully considered.

Furthermore the addition of WSUD technologies is paramount to creating a sustainable solution and

one which also incorporates a high level of community acceptance. The main WSUD features are the

wetlands. Figure 1 below shows the proposed route for the culverts and the proposed locations for

the wetlands.

Figure 1 - Culvert and Wetland Location Map (Tonkin Consulting 2014)

2

2 Key considerations

Services 2.1

There are a number of services that exist underground through the proposed area of construction

for the new culverts. These services provide residential properties and local businesses with

essential day-to-day necessities, such as; power, waste water pumping, telephone lines and more. It

is vital these services be noted for design and avoided if possible during construction. A particular

service that needs to be addressed is the main sewer lines that run parallel with Marion and South

Roads.

Culvert Design 2.2

The reinforced concrete box culverts (RCBC) are to be designed as two standard sized RCBCs running

parallel along the designated roadways. These RCBCs will be crossing over two very busy main roads

in South Road and Marion Road. This will mean having to withstand heavy vehicular axial loads, soil

and road base loadings and finally loads from the stormwater.

The size of each culvert is approximately 2300mm x 2400mm with 300mm freeboard and a thickness

of 300mm. The total length of the culverts is 3600m and the material used will be reinforced

concrete. The loads that need to be taken into consideration include the live loads, which consists of

traffic as well as the load of the water that flows through the culverts and dead loads which include

self-weight of the culverts and the weight of the road and soil. These factors are illustrated in Figure

2 below.

Figure 2 - Visual illustration of the traffic soil loads on the culverts

3

Slope 2.2.1

The gradient of a culvert is dictated by the minimum and maximum allowable flow velocities in the

culvert. The minimum gradient is the flattest allowable to minimise deposition and accumulation of

silts in the culvert, and the maximum gradient in the steepest allowable to control flow velocities to

a level not exceeding the scouring resistance of the culvert material. Minimum gradient is 1:600 and

maximum gradient is 1:100. Generally gradients of 1:200 to 1:300 are used for ease of laying and

minimum velocities requirements.

Joint Type 2.2.2

Wrapping one and a half times around the joints with geotextile filter fabric will be adopted. The

fabric should extend at least two feet either side of the joint or edges of the connecting band if one

is used.

Allowable head water and consideration 2.2.3

The following should be considered in selecting the design headwater elevation:

Anticipated upstream and downstream flood risks, for a range of return frequency events.

Damage to the culvert and the roadway.

Traffic interruption.

Hazard to human life and safety.

Headwater/Culvert Depth (HW/D) ratio.

Low point in the roadway grade line.

Roadway elevation above the structure.

Elevation at which water will flow to the next cross drainage.

Relationship to stability of embankment that culvert passes through.

The headwater elevation for the design discharge should be consistent with the freeboard and

overtopping criteria.

4

Culvert inlet structure selection 2.2.4

Side-tapered inlet as shown in Figure 3 is recommended to be adopted.

Figure 3 - Culvert Inlet (Worley Parsons, 2001)

Outlet flow velocities and consideration 2.2.5

The outlet velocity is the velocity measured at the downstream end of the culvert, and it is usually

higher than the maximum natural stream velocity. This higher velocity can cause streambed scour

and bank erosion for a limited distance downstream from the culvert outlet. Permissible velocities at

the outlet will depend upon streambed type, and the kind of energy dissipation (outlet protection)

that is provided.

If the outlet velocity of a culvert is too high, it may be reduced by changing the barrel roughness. If

this does not give a satisfactory reduction, it may be necessary to use some type of outlet protection

or energy dissipation device. Most culverts require adequate outlet protection, and this is a

frequently overlooked issue during design.

Variations in shape and size of a culvert seldom have a significant effect on the outlet velocity. Slope

and roughness of the culvert barrel are the principal factors affecting the outlet velocity.

5

Soil cover 2.2.6

Developing a design with a target depth of cover of about 0.5-1m that typically follows the surface

profile along the culvert route. This minimises cost and disruption that may otherwise be incurred if

significant excavation depths are required.

Manholes 2.2.7

Some considerations required for manholes when designing them include:

1. Culverts are accessible through manholes and a manhole cover hook is appropriate for

removing these covers.

2. Manholes are provided at all turning points of the culvert.

3. Maximum spacing between manholes is 180m.

4. Precast concrete manholes will be used since it is easy to install, specifically, manhole of

rectangular structure is used.

5. Sufficient freeboard at junctions is maintained according to the Australian standards.

Additional consideration 2.2.8

1. Construction methodologies and detail, including width of trenching required for culvert

installation and the methods to deal with crossing of major roads.

The minimum velocity of water in the culvert should be 2m/s to prevent sediment position.

6

Recreational Amenities 2.3

Prestige Worldwide has identified an abundance of opportunities for recreational amenities along

LBHC which can be implemented. In order to achieve this, the design team should aim to look for

more possible locations to construct the recreational amenities, for instance the implementation of

a picnic area, BBQ facilities, lighting and footpath/bike track.

Some of the amenities that have been thought of require a small space to be implemented. Thus,

these spaces along the creek have to be identified before amenities can be implemented. Figure 4

below indicates the route of the track/path along the creek and the spaces.

Figure 4 - Identification of locations of amenity along track/path route (Adapted from Google Maps 2014)

Also, there are some proposed areas for open spaces, they are located along Birdwood Terrace and

between Garfield Avenue and Cross Terrace; also known as the Grassmere Reserve. Figure 5 below

indicates the proposed area for open space. Recreational amenities can be implemented in these

two areas to provide more public facilities for the community.

Figure 5 - Location of Open Spaces and the Grassmere Reserve (Adapted from Google Maps 2014)

7

Wetland Design 2.4

Constructed wetland systems designed for stormwater treatment typically have an open water inlet

zone, a macrophyte zone (the majority of the system), and an open water outlet zone. Large systems

may consist of parallel or multiple sequences of this general pattern. An example of a wetland layout

is shown in Figure 6.

Figure 6 - Wetland Layout (Melbourne Water 2010)

There are several key features required in every constructed wetland, these features include:

1. A deep open water sedimentation pond/basin that acts as an inlet zone for the overall

constructed wetland system. The sedimentation pond reduces the inflow velocity and traps

coarser sediment.

2. An extensively vegetated macrophyte zone to trap finer sediments and soluble pollutants. A

deeper section is required around the outlet to provide an open water zone for the outlet

structure.

The connection of the sedimentation basin to the macrophyte zone can be either by pipe, culvert or

porous rock weir. Where pipe connections are used it is important to have an initial open water

section in the macrophyte zone to help disperse flows. Pipe connections would typically be sized to

pass no greater than the 1 year ARI flow.

8

Geotechnical considerations for Wetland design 2.4.1

Clay is considered to be the most suitable soil for use in constructed wetlands. However, the clay is

required to have low permeability with a low to moderate plasticity. Clay may be used as surface

layer for the wetlands particularly clay loam or silty clay loam (ML - CL USC group) which has low

permeability and medium plasticity. Table 1 contains the soil type and groundwater level

information at the recommended wetland locations.

Spillways are needed for the wetland to allow the water to flow in and out of the creek. In this case,

the size of the spillway used and the wetland must be designed properly in order to achieve the

project’s requirement. Suitable soil to be used for the wetlands surface needs to be established since

inappropriate soil may cause erosion or cracking in the event of 1-in-100 years. The excavation

involves ‘cut and fill’ of soil and rock for the wetland and spillway approach. The appropriate size of

spillway and the size of wetland need to be designed prior the commencing excavation.

Table 1 - Soil type and groundwater level for Wetland locations.

Location Soil Type Groundwater level

Wetland 1 Brown and orange-brown sandy

clay of medium-high plasticity and

very stiff to hard consistency

Not expected above 4 meters.

Perched water may be expected

locally

Wetland 2 Expected brown and grey sandy

clay and silty clay of medium-high

plasticity and very stiff to hard

consistency

Did not encounter to 4m depth in

previous nearby investigations.

9

Retaining Walls 2.5

It is proposed that sections of the channel section require the use of retaining walls to retain non-

engineered fill or natural clays of variable density and consistency. Gabion walls shown in Figure 7

are the recommended earth-retaining structure to be implemented where required due to their

resistance to being washed away by moving water, conformity to ground movement, and the ability

to dissipate energy from flowing water to prevent further soil erosion. Rip rap, a cost-effective

alternative to scour protection, is a man-made barrier of rocks which helps to slow or stop areas of

erosion. Both of these options are recommended solutions to instances of soil instability or erosion

along the length of the creek.

The chosen dimension of each Gabion basket is 2.1m width, 0.375 m height and 0.3m depth. Each

box will cost about $87.20 (Gabion 2013). Angular rock will be used for the fill as it provides a good

interlock and therefore less deformation of the face occurs. Approximately 4.5mm wire gabion

basket coated with galfan (95% zinc, 5% aluminium) is proven to be 2 to 3 times more corrosive

resistant than the same thickness of hot dip 100% zinc galvanising.

Figure 7 - Gabion basket retaining wall (Riverdale 2011)

10

Earth-retaining structures 2.5.1

The retaining walls should be designed in accordance with the recommendations of AS4678-2002

“Earth Retaining Structures”. The specific locations and remediation options for earth-retaining

structures are identified in Table 2.

Table 2 - Proposed sites for earth-retaining structures

Location of soil instability and/or erosion Suggested action

Daly Street to McArthur Avenue The most substantial area of erosion, with the runoff

from channel flows and surface water runoff

considered to be among the main cause of erosion in

this area. Implementation of a stepped gabion basket

wall in tight bend of channel section is suggested for

this section.

Birdwood Terrace and Warwick Avenue Noted unsafe bank stability through this section.

Stepped gabion basket wall or reinforced Earth as

well as re-vegetation are suggested. Riprap may be

implemented where bank slope is flatter angle.

Grassmere Reserve Erosion noted around existing culvert and the

exposure of tree roots in natural creek bed may de-

stabilize the occupying bank. An abutment, made

from sustainable materials, or gabion basket wall can

be implemented where there is erosion near culvert.

This particular location can be viewed from the road,

thus both are suitable due to aesthetic features.

Tilden Avenue High Erosion with vertical cut undermining property

near the pedestrian bridge that requires stabilisation

and it must be noted that localised slumped fill

materials dominate this channel section. Gabion

basket wall for the length of the erosion is the

recommended action.

11

Geotechnical Considerations 2.6

The findings contained within this section of the Prestige Worldwide Detailed Design Brief are based

on the geotechnical assessment of the LBHC catchment and present site specific data, remediation

actions, requirements and the final outcomes. Key information of the geotechnical assessment

includes the expected subsurface conditions, brief methodology of the geotechnical works,

considerations, limitations and recommendations to ensure the project is successfully completed in

relation to achieving the required flow capacity of 60m3/s while taking action to minimise any

inconveniences or undesirable consequences of geotechnical works on the local community and

environment.

Subsurface conditions 2.6.1

The current conditions of the LBHC catchment is divided into 3 sections with similar soil properties.

Table 3 and 4 gives an overview of the subsurface conditions in the Lower Brown Hill Creek

Catchment region. It is accepted that these subsurface conditions are used when conducting the

excavation of the proposed culvert system as its route is adjacent to the creek channel.

Table 3 - Current soil conditions

Section Soil types Groundwater levels Soil permeability

From Anzac

Highway to

Daly Street

Red Brown clay (RB5 and RB3)

with blocky.

At upper 4m was natural soil

with red brown, brown, orange

brown clay and sandy clay of

medium (high plasticity and

very stiff to hard consistency).

Below at 7m had some gravelly

lenses

Expected Hindmarsh clay at

below 9m.

11m at Basnett Street and

perched water may be

present locally

Min /5.00E-09 (m/s)

Max/ 5.00E-06(m/s)

12

Table 4 - Current soil conditions continued

Section Soil types Groundwater levels Soil permeability

From Daly

Street to

Marion road.

Red Brown clay (RB9)

Silty clay mottle over brown

silty clay with granular

structure. Also contains some

lime and becomes sandy with

depth.


with brown and orange brown

sandy clay of medium.

High plasticity and very stiff to

hard consistency.

Not expected above 4m

and perched water may be

present locally.

Min/ 5.00E-09 (m/s)

Max/ 1.00E-06(m/s)

From Marion

road to Watson

Avenue

Have poor drained alluvial soils

of the lower Outwash plain

comprising Red brown clay

(RB9) and dune sand (DSI).


with brown and grey sandy clay

and silty clay of medium to

high plasticity.

Very stiff to hard consistency

and variable calcareous

inclusion.

Sandy alluvial units such as

clayey sand and possibly

gravelly sand. Silty sand layers

may present in the western

extent.

Seasonal variations should

be expected and may be

reflective of water levels in

the adjacent channel.

Groundwater not

encountered at 4m depth

in previous nearby

investigations.

Min/ 4.00E-04(m/s)

Max/ 4.00E-03(m/s)

(At Upper 4 metres)

Min/ 1.00E-05 (m/s)

Max/ 5.00E-05 (m/s)

13

Recommended batter slopes are listed in the Table 5 below. However it should be noted that where

steeper channel slopes than listed below are present a retaining wall structure may be necessary.

Scour and erosion protection of unlined batters, such as rip rap (fortified with large boulders) or

planting a few trees to ensure bank stability and low maintenance, are suggested in areas with

restricted access.

Table 5 - Slope details

Batter slope Soil type

1H : 1V Clay

1H : 1.2V Natural soil and engineered fill

2H : 1V Fill and coarse granular soil

3H : 1V Natural soil above ground water table

14

Traffic Considerations 2.7

Diversion of Traffic 2.7.1

The diversion of traffic is an important component to the project as this development would affect a

number of road networks including major ones such as Marion Road, South Road and Anzac

Highway. This includes traffic diversions that will occur during the construction phase as well as after

commissioning where maintenance works may be carried out.

Routes to Access Points 2.7.2

In terms of traffic management, the location of the access points would be required for it to be safe,

predominately for access during maintenance works. Thus, the affected roads during maintenance

would have to be low in traffic as well as easy to access.

During construction, access to site specifics would require a more in depth analysis of the roads

surrounding it as traffic flow might affect the time taken for the materials and equipment to be

transported. Vice versa, the transportation of equipment and materials might also affect the flow of

traffic. Thus, routes to these points would have to be low in traffic and contain less detours and

bends where long vehicles and trailers are required for transportation.

Like the diversion of traffic component, this design would detail the works required during the

construction phase as well as after commissioning where maintenance works may be carried out.

Bike Track and Footpath 2.7.3

The bike track and footpath is one of the main recreational amenities which will be implemented

with this project development. Its main objective is to provide a connection between existing

bikeways which includes Captain McKenna Bikeway, Westside Bikeway and Mike Turtur Bikeway for

the length of the development. As the design for this amenity runs mostly along the existing creek,

collaboration with the existing creek team would need to be done. This is to ensure that the design

of this amenity could be enhanced purposefully such as providing easier access to the existing creek

for maintenance as well as to be designed as close as possible to the proposed wetland. In addition,

should the width of the wetland proposed be extended, the design of the bike track and footpath

should not interfere with the wetland design.

15

Maintenance of Creek and Culverts 2.8

Regular schedule of maintenance is the key to effective maintenance. Maintenance will help in

ensuring that both channel and culverts are operating to the design flow capacity well in advance of

rainy seasons.

Channel Maintenance 2.8.1

Channel maintenance is important to sustain the design capacity in weather extremes. Overtime, the

water flow in channels will be accompanied by deposition and erosion of the channel banks and

vegetation. The rate of erosion of banks depends on the channel characteristics, erosive energy of

the water flow and the condition of the natural bank vegetation. Eventually, the severity of erosion

will contribute to channel defects and affect the structural integrity of the water channel. Most of

the channel sections are accessible by adjacent roads which makes maintenance easier.

Figure 8 - Example of area that may require maintenance

The areas identified for maintenance in regards to the channels include:

1. Concrete wall and channel lining as shown in Figure 8

2. Banks of the natural waterways which show signs of erosion

3. Damaged retaining walls

4. Build-up of natural matter in both natural and natural waterways

5. Felled trees and plants

6. Build-up of litter and garbage from residents

7. Channel fencing

8. Services which run across channel (sewer and other utilities)

9. Access ramps for machinery and maintenance

10. WSUD features along the channel

11. Pedestrian bridge maintenance

12. Vehicular bridge and culvert maintenance

16

Culvert maintenance 2.8.2

Culvert maintenance ensures that no blockages are present and the design flow is met. Blockages

may result in backflow during weather extremes causing floods and damage to properties and roads.

The main concern for maintenance would be the presence of tree roots along the roads. Overtime,

tree roots may penetrate the concrete culvert causing cracks and defects. This will breach the

concrete lining allowing soil and matter to collect within culverts. This reduces the efficiency and

carrying capacity of the culvert. Crack and defects may cause structural integrity issues which could

cause a road collapse if maintenance is not properly done.

The areas identified for maintenance in regards to the culverts include:

1. Concrete culvert wall lining, sumps, headwalls, wing walls and aprons for signs of breakage or wear

2. Build-up of soil and matter within culvert obstructing channel 3. Build-up of litter and garbage obstructing channel 4. Examination of inlet and outlet areas 5. Examination of safety nets or debris net at the inlet area

17

Environmental Considerations 2.9

A short summary of identified environmental issues of the development is listed in the following

sections. Mitigation measures are detailed in the EIA document which will be required to be further

detailed in the Environment Management Plan (EMP) on how each measure will be implemented

throughout the project.

Water 2.9.1

The main environmental concern with regards to the water aspect of this upgrade is the quality of

stormwater runoff that will eventually end up in Keswick Creek. It is essential to ensure that waste,

debris and litter before and after construction and demolition is controlled to prevent any

contamination of stormwater runoff. Measures to prevent potential pollutants from machinery leaks

and chemical used should also be considered. During operation, monitoring measures should be

undertaken to ensure that quality of runoff is monitored.

Land 2.9.2

Land issues such as landforms, soil quality and slope stability need to be considered. It has been

established that impacts on the identified land issues will not be major due to the location of the

culverts. With regards to soil quality, continuous monitoring will be necessary. In addition, any

potential spills during construction and post-operation will have to be prevented. Specific locations

for chemical and waste storage should be allocated to minimise potential spills and contamination.

Flora and Fauna 2.9.3

It has been determined that the current conditions of the creek provide poor quality conditions for

both native and exotic flora and fauna. It is recommended that native flora and fauna should be

protected especially during construction and post-operation phases. Measures should be taken to

prevent soil compaction from the weight of heavy machinery. Ensuring that vehicles and machines

are cleaned before entering the work site is recommended to prevent any contamination. During the

refurbishment of the existing creek, revegetation of native flora should be looked into to enhance

the biodiversity of the creek and its surroundings. In addition, it is recommended that a variety of

trees be planted to provide the habitat needs for birds, and shelter for fish. Dense vegetation such as

bushes should be incorporated for reptiles to keep cool and thrive in. Lastly, it is expected that the

presence of wetlands will provide an opportunity on flora and fauna enhancement.

18

Air Quality 2.9.4

Any large project has the potential to create unwanted dust emissions that can cause a nuisance to

local residents while having a negative impact on the environment due to contamination issues

associated with high levels of air pollution. The use of heavy construction and demolition machinery

will result in high levels of dust emissions and other air emissions such as exhaust fumes. Due to the

high level of activity that will take place during this phase, ensuring that equipment is maintained

will help reduce the level of exhaust fumes. In additional, emissions of pollutants due to machinery

leaks should be mitigated as well. Mitigation measures will have to be adopted to ensure that air

pollution during construction is minimized as much as possible.

Noise Pollution 2.9.5

Noise from machinery and construction works is a given on almost any construction site and under

normal circumstances cannot be prevented. The construction equipment, machinery and an

increase in human and vehicle traffic due to the upgrade will create an increase in the noise volumes

and durations in the area. It is recommended that neighbours will be notified of all hours of heavy

equipment operation, which will be completed at times as determined to have the smallest

inconvenience to local residents. In addition, heavy machinery should not be operated outside of

these normal operating hours. Post construction noise levels will return to normal.

Community and Heritage 2.9.6

It is important to consider the location of community and heritage sites when designing a large

development in order to determine any effects the project might have on these sites. If the site is

found to be located within one of these important areas then certain precautions must be taken.

Heritage sites may be listed on the Council’s Heritage register of Unley and West Torrens under the

Heritage Places Act 1993. The main heritage sites in the project area are:

1. Gum Tree Stump – Remains of a gum tree, a remnant which stood on Everard family

property (Jensen + Design Planning 2013) and is currently being cared for by the West

Torrens Historical Society.

2. Ashford House School – Ashford Special School is considered of importance to the local

area based on historical, economic and social themes and is protected based on the

Development Act 1993. It is considered a notable landmark in the area.

19

3. Mature Oak – Originally formed part of the Ashford House Guards and considered of

importance to the local area and a notable landmark.

4. Former Railway Corridor (Birdwood Terrace) – Former Holdfast Bay railway corridor now

serves as a shared path for cyclists and pedestrians for Mile End to Glenelg.

5. Adelaide Airport – While not a heritage site, Adelaide Airport is a significant landmark and

international airport that must be taken into consideration.

All of these sites listed above must be considered during the construction phase of the project,

specifically during the maintenance of the creek to facilitate water flow along the creek and through

the culverts. The exact locations of the mentioned sites are shown in Figure 9.

This development will have many social implications within the area. The construction of wetlands

will provide recreational amenities and opportunities for the community that will ensure the support

of this critical stakeholder.

Figure 9 - Heritage Sites along LBHC (Adapted from Tonkin Consulting 2014)

20

There will be some concerns from the community during construction, for example, the Ashford

Special School is located near the work site where culverts will be installed. Measures must be taken

to protect the school's students and teachers return from home and school safe and convenient.

These measures can include designating isolation area and the use of safety signs around the school

during the construction. In addition, measures should be undertaken to ensure inconvenience to the

community during the construction phase can be minimised.

Another concern is the community is with regards to the wetlands, the residents might think the

wetland will bring unhealthy effects, such as the spread of disease caused by mosquitoes and child

safety issues. Monitoring measures should be undertaken to ensure that negative impacts are

prevented.

Land Acquisition 2.9.7

With regards to the construction of culverts under existing roads, no land acquisition will be

required. However it is possible that further investigations during detailed design stage can result in

land acquisitions. In that case, the amount of land to be acquired as well as possible social issues

that arise from this has to be documented. A relocation plan can also be considered.

21

Affected Businesses 2.9.8

It has been discovered that four identified business will be affected during the construction phase of

the development. These four businesses are namely, Monier Wunderlich Roofing, PGH Bricks and

Pavers, Harvihill Steel Fabricators and Adelaide Automatics. The locations of these businesses are as

shown in Figure 10 below. In addition, two schools namely Goodstart Early Learning Marleston and

Ashford Special School have also been identified to be affected by this development.

Figure 10 - Affected businesses (Adapted from Tonkin Consulting 2014)

Adelaide Automatics and Harvihill Steel Fabricators would be affected when Marion Road gets

closed although Harvihill Steel Fabricators has another entry point along Dudley Avenue. Harvihill

Steel Fabricators would be fully affected though where the culvert is chosen to be developed.

Monier Wunderlich Roofing & PGH Bricks and Pavers will be affected as well due to its entry point

being along Tyson Street where the culvert would be.

The Ashford Special School would be affected when Anzac Highway needs to be closed for this

development. While the Goodstart Early Learning Marleston is situated two streets away from the

creek, the noise would definitely affect the focus of the students and staff. This poses as a safety

issue as well as there would be children within the area of development.

22

Bus Routes 2.9.9

Bus routes within the area of the map shown in Figure 11 below have been identified. Affected roads

where the bus services run through would be Harvey Avenue, Marion Road, Tilden Avenue, Daly

Street, South Road and Anzac Highway. These routes would have to be diverted when these parts

are up for upgrading. Applications would have to be made to disrupt the normal routes of the

affected services. Careful considerations would also have to be taken to ensure that diversions for

the buses do not affect the residents severely and to minimise damage to roads.

Figure 11 - Bus routes within the area of the map (Adapted from Tonkin Consulting 2014)

23

3 Scope for Detailed Design

Deliverables 3.1

The Detailed Design will require certain items to be supplied upon completion. These will form the

core of the Detailed Design and will contain all the necessary information. The following documents

will be provided in both soft copy and hard copy forms as per the convenience of the client.

1. Final Report

2. Environmental Management Plan

3. Quality Management System

Contained within these documents the following information will be outlined in the appropriate

manner.

1. Design calculations

2. CAD drawings

3. Contract documents

4. Technical specifications

24

Proposed Organisation Structure 3.2

Figure 12 - Proposed Management Structure

Project Manager

Existing Creek Department

Department Leader

Senior Engineer

Senior Engineer

Graduate Engineer

Graduate Engineer

Water Department

Department Leader

Senior Engineer

Senior Engineer

Modelling Engineer

Modelling Engineer

Graduate Engineer

Graduate Engineer

Recreational Amenities

Department

Department Leader

Senior Engineer

Graduate Engineer

Construction and Operation

Department

Department Leader

Senior Engineer

Graduate Engineer

Environmental Department

Environmental Manager

Contract Department

Department Leader

Contract Manager

Drawings and Website

Coordinators

Drafter

Website Designer

Assistant Project Manager/Quality

Manager

25

4 Project Schedule

A detailed project schedule is shown in Appendix C. Table 6 below consists a list of key dates during

the period of the detailed design stage.

Table 6 - Key Dates of Project

Key Dates Description

5 May 2014 Start of Detailed Design Stage.

26 May 2014 onwards Draft Department Reports Compilation.

2 June 2014 onwards Amend and Finalise Detailed Design Report.

4 June 2014 onwards Presentation Slide Preparation.

10 June 2014 Submission and Presentation of Detailed Design Report to

Client.

26

5 Proposed structure breakdown

The information outlined in the proposed teams is not all encompassing, there may be additional

information required from each team that has to be included. Amendments and more work will be

required during the progress of the detailed design stage. The exact number of employees in each

department is shown in the chart of Figure 12.

Project Manager 5.1

The project manager is responsible for overseeing the entire project, ensuring targets and deadlines

are met and that the outcomes are to the desired standard. Part of project manager is ensuring that

each team has clear and attainable project objectives as well as liaising with the clients in the

appropriate manner.

Assistant Project Manager/Quality Manager 5.2

While the main focus of this role is to aid the project manager another focus is the quality

management system. Ensuring that the quality management system is in place and is being correctly

used is imperative to having a smoothly run organisation. Furthermore after the original internal

audit by Prestige Worldwide, the following corrective actions are recommended to be taken:

1. Internal Audit Templates have to be revised to ensure that it covers all of the procedures in the

QMS.

2. It will be highly emphasised by the Project Manager and Quality Manager to ensure that drafts

submitted have to be proof read by the Team Leaders before submission.

3. The Quality Manager will collect meeting minutes weekly. The Quality Manager will have to

ensure that received meeting minutes contains enough details. If not enough details are in the

minutes, Team Leaders have to redo it.

4. Project Manager will have the responsibility to ensure deadlines are achievable by each

department.

5. In the detailed design stage, employees will have to report actual hours of work done.

6. Timesheets will have to be submitted on Mondays during project time.

27

Existing Creek 5.3

Although construction of the culvert will be the main contributor to the increase of water flow in the

Brown Hill Creek system, it is still important to ensure that the existing natural creek is utilised and

maintained. In the detailed design stage there are several factors that need to be considered.

An important step in completing this section is to detail the geometric features of the existing creek

in a clear and concise format. Such features include the length, width, slope and depth running along

the length of the creek. This will require research into the features of the creek, detailing the

required changes necessary to the existing structure, the addition of CAD drawings will be required

in order to allow for clear interpretation. Hydraulic modelling may be required to illustrate the

upgrades of the existing creek and the resultant impact.

Furthermore a detailed plan to perform maintenance on all parts of the creek will be necessary. This

includes cleaning of the creek that is required to happen immediately and to administer plans in

order to continue the maintenance and cleaning in accordance with a repair schedule. Inspections

are generally classified into 3 categories which are general inspections, periodic inspections and

special inspections. Similarly inspections will be required for the culverts as well.

Effort to prevent contamination needs to be detailed, source of soil contamination could be

industrial waste, food, drinks, and personal waste; also the machinery leaking (chemicals) may lead

to soil contamination. There are different approaches to cleaning up contaminated soil.

1. Soil can be excavated from the ground and be either treated or disposed

2. Soil can be left in the ground and treated in place

3. Soil can be left in the ground and contained to prevent the contamination from becoming

more widespread and reaching plants, animals, or humans.

28

Construction of wetlands will be required, with such considerations as design criteria, catchment

characteristics and the various zone layouts investigated in depth. Some key considerations are

listed in Appendix A as well as in the following list.

1. Climate

2. Verifying the size and configuration of the sedimentation pond and macrophyte zone. To

determine m2 required for the surface area of the wetland

3. Determining design flows, drainage levels (including assessment of the 100 year ARI flood

levels). The stormwater inflows up to the peak one year ARI discharge into the

sedimentation pond.

4. Layout of the macrophyte zone depends on size and dimension for the ratio of the length of

design.

5. Hydraulic modelling of the design to verify the hydraulic performance and investigations to

ensure that the design does not cause adverse flooding of the area.

6. A bypass weir and channel.

7. Inclusion of a gross pollutant trap as part of the treatment plan.

8. Does the maximum flow through the sedimentation basin satisfy the sedimentation scour

threshold of 0.5m/s during the 100 year ARI event?

9. Does the maximum flow through the macrophyte zone satisfy the biofilm scour threshold of

0.05m/s for the 3 month return interval event and 0.5m/s for the 100 year ARI event?

WSUD technologies should be outlined in detail, including the exact capacity, location and

dimensions of any chosen technology. This should be an extensive investigation help make this into

a sustainable solution that benefits both the community and the environment. Examples of

technologies may include infiltration trenches, bio-retention systems, filter strips, bio-infiltration

swales in addition before mentioned wetlands.

29

Water Team 5.4

The main task of this department is the culvert design and hydraulic modelling concerning the

culverts. A detailed solution encompassing all the required sections of the culverts will be required.

This will include an outline of geometric requirements, joint type, cover requirements, outlet flow

velocities and the allowable headwater. Such a solution may require the culverts to be diverted back

into the creek for a short period which in turn will alter the design. This final solution will be reached

in collaboration with Existing Creek Department.

Using the software DRAINS a final solution can be reached and determined with accuracy. The

solution will also need to take into account all the services that will be encountered such as the main

sewer line that runs along Marion and South Road. Additional services will need to be explored in

detail; this includes but is not limited to the drains that will be affected by the addition of culverts,

water supply networks, as well as the electricity and telecommunication networks.

Additionally CAD drawings along the length of the culverts will be required to clearly illustrate the

design solution, the use of the drawings will allow for clear interpretation of the culvert design.

Recreational Amenities 5.5

Recreational amenities are essential in order to promote community acceptance, as such this

department will be required to investigate in depth the recreational amenities available. This will

include such options as picnic areas, waste bins, BBQ pits, playground and exercise stations, benches

and various rest areas in addition to the lighting required along the paths or irrigation systems that

may be implemented.

Furthermore the construction of the bike paths and pedestrian paths will have to be detailed, with

the possible use of permeable paving explored. The required signage along the path will be

necessary as well as the required dedicated bike markings that would be required to be painted.

Throughout this stage the recreational amenities will need to include exact locations and

dimensions, with CAD drawings required for a concise presentation of each option.

The CAD drawings will be required in incorporate a plane view, long section and cross section view,

additionally pavement analysis to determine maximum load bearing capacity as well as the required

thickness necessary. Such analysis will require use of the software CIRCLY.

30

Construction and Operation 5.6

The construction and operation of the culverts will be detailed by this department. Such aspects will

include investigating the construction issues associated with expansive soils, the location of the

machinery throughout the construction phase as well as the exact access points required for the

machinery. Traffic control throughout the construction phase will be crucial to minimise the impact

on local residents as well as commuter’s who bypass the area. Detailed instructions for detours and

the required road diversions will be necessary. This will include the local bus routes as well as

vehicles, indicating the required signage, labour hours as well as the number of days required for

each section of the construction. The accessibility for local traffic and proposed speed limits during

construction will need to be addressed as well as mitigation methods for the local businesses and

communities.

Additionally maintenance points along the culverts will be required in the event that the culverts get

blocked during a flood event. Furthermore maintenance of the culverts themselves will be required

to ensure continuous safety throughout the operation phase. Manhole locations will have to be

show, as well as the design and dimensions of the manholes. An inspection schedule will have to be

drawn up as failure of a culvert has the potential to be a catastrophic event.

During the construction phase cut and fill will be necessary for the culverts, the exact volume of cut

and fill will need to be determined. Additionally the length of road that will be closed off during each

phase of construction is to be indicated precisely by the centreline chainage. Throughout this

sections CAD drawings are necessary for clarification, this includes such features as the maintenance

points, manholes as well drawings to display the cut and fill requirements along the length of the

culvert.

31

Environmental Management 5.7

According to the EIA done during the Feasibility Study, the upgrade of LBHC will result in numerous

environmental issues during the construction, operation and post-operation phase of the

development. An EMP is a tool to implement environmental management measures throughout the

life of the project by providing a framework to ensure all identified environmental issues are avoided

or mitigated. In addition, the EMP will have to comply with environmental legislations.

A detailed EMP will be required to address all environmental issues in each phase relevant to the

design and appropriate measures necessary for the management of the local and downstream

environment. This will include prevention, control, mitigation, corrective actions, inspection and

monitoring measures that will be carried out during the project to ensure that negative impacts on

the environmental throughout the project is minimised.

Contract Management 5.8

Contract Management will be in charge of developing a cost estimate for the detail design. This will

require collaboration with the other departments in order to make an accurate and detailed cost

estimate. To develop an accurate cost estimate an extensive bill of quantities will be necessary for

each section of the project, listing the materials and parts required in detail, along with the

corresponding costs. The bill of quantities will be provided by each department in a timely manner

to allow for adequate time to source accurate costs.

Furthermore all legislation and contract requirements will be handled by this department, due to the

environmental nature of this project and the urban setting there are several key legislative processes

that are required to be closely followed as well as completion of the appropriate approvals and

permits required to begin construction which will need to be covered in details. Whilst ensuring

compilation with all necessary legislation.

32

Drawings and Website Coordination 5.9

Detailed drawings are an essential component of the detailed design. The propose of these drawings

is to give a visual representation of the work to be undertaken as well as enabling estimates of the

construction materials and resulting cost to be made. Comprehensive templates and collaboration

with each team will be required to ensure proper documentation and drawings.

This department will be required to ensure that each drawing is produced by Prestige Worldwide is

completed to industry standard and the members in this department will be required to oversee the

completion of the drawings as necessary to ensure this.

Additionally this department will be required to develop and design a webpage for Prestige

Worldwide, the webpage will need to encompass the entirety of the work produced by Prestige

Worldwide at each stage of the project. Furthermore the webpage produced will need to contain all

the information that would normally be included on such a page from consulting firm, including but

not limited to; values, purposes, history and policies.

33

6 Costing

Hourly Rates 6.1

The cost of this phase is made up entirely of employee wages, with a total of 27 employees each

with varying rates. The rates of each employee depend on the level of responsibility to be

undertaken for this stage of the project as well as prior experience. The Table 7 summarises the

hourly rates for each employees.

Table 7 - Hourly Rates

Position Hourly Base Rate Hourly Base Rate (Inc. GST)

Project Manager $240 $264

Quality Control Manager $240 $264

Department Leaders $230 $253

Environmental Manager $230 $253

Senior Engineer $220 $242

Modelling Engineer $200 $220

Drafter $200 $220

Website Designer $200 $220

Contract Manager $200 $220

Graduate Engineer $160 $176

Based on the rates shown above, Prestige Worldwide has calculated that the total cost of the

detailed design will be $364,320.00 (GST included). This is based on each team member working 12

hours a week over a period of five weeks. The detailed cost proposal is shown in Table 8 on the next

page.

34

Detailed Cost Proposal 6.2

Table 8 - Detailed Cost Proposal

Department Position Hourly Rate

(Inc. GST)

No. of

Staff Hours/week Weeks

Total Cost

(Inc. GST)

Project Manager

Project Manager $264 1 12 5 $15,840

Total $15,840

Quality Control Manager

Quality Control Manager $264 1 12 5 $15,840

Total $15,840

Existing Creek Department

Department Leader $253 1 12 5 $15,180

Senior Engineer $242 2 12 5 $29,040

Graduate Engineer $176 2 12 5 $21,120

Total $65,340

Water Department



Modelling Engineer $220 2 12 5 $26,400


Total $91,740

Recreational Amenities Department




Total $40,260

Construction and Operation Department




Total $65,340

Environmental Management Department

Environmental Manager $253 1 12 5 $15,180

Total $15,180

Contract Department


Contract Manager $220 1 12 5 $13,200

Total $28,380

Drawings and Website Coordinators

Drafter $220 1 12 5 $13,200

Website Designer $220 1 12 5 $13,200

Total $26,400

Total $364,320

35

7 References

Cameron D 2013, Geotechnical Engineering lecture notes, University of South Australia, Mawson Lakes

Gabion 2013, Stock Sizes and Prices, Square Gabion Walls, Gabion1 Vineyard 2765 NSW, viewed 1st May 2014. < http://www.gabion1.com.au/gabion_aus_prices.htm >

Jensen Planning + Design 2013, Lower Brown Hill Creek: Planning issues report, Tonkin Consulting, Adelaide

Melbourne Water 2010, Constructed Wetlands Guidelines, Victorian Government, Melbourne.

Riverdale Mills Corporation 2011, Riverdale gabion baskets, Riverdale Mills Corporation, viewed 1st

May 2014, <http://www.riverdale.com/images/basket2.jpg>

Worley Parsons 2001, Drainage Manual - Urban Drainage and Flood Control District, Worley Parsons,

Adelaide.

36

8 Appendices

Appendix A – Wetland Design Checklists

Figure 13 - Wetland Calculation Checklist

37

Figure 14 - Wetland Assessment Checklist

38

Figure 15 - Construction Inspection Checklist

39

Figure 16 - Asset Handover Checklist

40

Figure 17 - Wetland Maintenance Checklist

41

Appendix B – Culvert Maintenance Checklist

Figure 18 - Culvert Checklist (Worley Parsons, 2001)

42

Appendix C – Gantt

Chart

Detailed Design Brief: Upgrade to Lower Brown Hill...

Documents

Transcript of Detailed Design Brief: Upgrade to Lower Brown Hill...