Original source · versioned page text
Stormwater Management Plan
Attached to the e-mail MCU16/0066 & OPW16/0133 - Engineering report & Stormwater Mgmt Plan (2 of 4).
Plans and drawings
This document appears to be plans or drawings. Its page text below holds only the words printed on the drawings, without the drawings themselves, so it may be jumbled or hard to follow. To see the plans as drawn, choose Original above or download the file (both need you to log in).
Log in to see the plans as drawnam COVEY ASSOCIATES PTY LTD Consulting Engineers STORMWATER MANAGEMENT PLAN HIGHWAY SERVICE CENTRE COOROY FOR HASS HOLDING ATF THE QUASAR TRUST DATE: JUNE 2016 PROJECT No: 161968 REPORT No: 100415 RPT ISSUE A Maroochydore | Gladstone | Rockhampton | Tamworth www.covey.com.au
See the original
The page text is free to read. Viewing or downloading an original file needs an account.
Log in to see the originalLog in to download the original file
Large file: the download may take up to a minute.
Searchable page text hides email addresses. Original files are unchanged and may show email addresses.
Full text of the other 26 pages
Page 2
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
DOCUMENT ISSUE APPROVAL
Project No: 161968
Title: Stormwater Management Plan
Client: Hass Holdings ATF The Quasar Trust
Date: June 2016
Issue: A
Distribution: Hass Holdings ATF The Quasar Trust – One (1) copy
Noosa Shire Council – One (1) copy
Covey Associates Pty Ltd – One (1) copy
© Copyright Covey Associates Pty Ltd (2016).
This document is the property of Covey Associates Pty Ltd. This document and the information
contained in it are solely for the use of the authorised recipient and this document may not be
used, copies of reproduced in whole or part for any purpose other than that for which it was
supplied by Covey Associates Pty Ltd. Covey Associates Pty Ltd makes no representation,
undertakes no duty and accepts no responsibility to any third party who may use or rely upon this
document or the information contained in it.
COPYRIGHT NOTICE: Parts of this document contain material originally prepared by:
This material is the intellectual property and copyright of Covey Associates Pty Ltd.
Author: Jennifer Mullaney Reviewed: Jade Mohr
MA (Hons), PhD BEng (Civil)
Reviewed: Chris Walker Reviewed: Shane Rynne
BEnvSc, BSc (Hons), PhD, CPESC BEng (Civil), GradDipMunEng, MIEAust
Page 3
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
CONTENTS
1.0 INTRODUCTION 1
2.0 SITE DESCRIPTION 1
2.1 Site Location 1
2.2 Previous Land-use, Topography and Drainage 2
2.3 Proposed Land-use 2
3.0 WATER QUALITY AND TREATMENT OBJECTIVES 2
3.1 Water Quality Objectives 3
3.2 Area of Treatment 3
3.3 Non-treatment Areas 3
4.0 WATER QUALITY MODELLING ASSESSMENT/APPROACH 4
4.1 Scenario Methodology 4
4.2 MUSIC Model Parameters 4
4.3 Land Use/Source Node Areas. 4
4.4 Proposed Stormwater Treatment Train 5
4.5 Pollutant Reduction Results 5
5.0 MAINTENANCE PERIOD 6
5.1 Bioretention Basin 6
5.1.1 Maintenance During ‘Construction Phase’ 6
6.0 STORMWATER QUANTITY 6
6.1 Stormwater Quantity Management 6
6.2 Hydrology (XP-RAFTS) 6
6.3 XP-RAFTS Data 7
6.3.1 Model Scenarios 7
6.3.2 Rainfall Intensities 7
6.3.3 Existing and Proposed Development Areas 7
6.3.4 Initial and Continuing Losses 7
6.3.5 Pervious and Impervious Areas 8
6.3.6 Manning’s Values 8
6.3.7 Catchment Slope 8
6.3.8 Storm Durations 8
Page 4
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
6.4 Calibration 8
6.4.1 Rational Method 8
6.5 Design Discharges Unmitigated 9
6.5.1 Peak Durations 9
6.6 Stormwater Detention 9
6.6.1 Detention Tank 10
7.0 CONCLUSIONS AND RECOMMENDATIONS 10
REFERENCES 11
______________________________________________________________________________
LIST OF APPENDICES
APPENDIX A Site Layout Plan by Reddog Architects
APPENDIX B Stormwater Management Plans by Covey Associates
APPENDIX C MUSIC Concept Map
APPENDIX D Stormwater Quantity Catchment Plans
APPENDIX E Rainfall Data, Rational Method Data and Results
Page 5
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
1.0 INTRODUCTION
This Stormwater Management Plan (SMP) contains information regarding the stormwater
management strategies for a proposed Highway Service Centre, including a fast food outlet at
Taylor Court, Cooroy. This report refers to the stormwater quality and quantity treatment measures
proposed of the site in its entirety.
Noosa Shire Council (NSC) requires that stormwater be appropriately managed prior to discharge
from the site. The Queensland State Planning Policy (2014) also requires that urban development
projects demonstrate how the potential impacts to receiving environments are mitigated.
2.0 SITE DESCRIPTION
2.1 Site Location
The site is located at 6 Taylor Court, Cooroy. The real property description is Lot 3 on SP197517
(Figure 1). The site is bounded by vacant land to the west and south, Taylor Court exists to the
east and Holts Road and the Bruce Highway to the north (Figure 2). The site is adjacent to the
newly upgraded section of the Bruce Highway.
A Site Plan is presented in Appendix A for additional information and details of the proposed
development.
Site
Area
Figure 1 - Site area
Covey Associates Pty Ltd 1 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 6
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Site
Area
Figure 2 - Site Locality (image accessed from Nearmap on 11 August 2015)
2.2 Previous Land-use, Topography and Drainage
The site is currently vacant land and was previously used as a temporary depot for the machinery
used for the upgrade of the Bruce Highway. The site predominantly drains from north to south, with
an approximate slope of 4%.
2.3 Proposed Land-use
The overall site area is approximately 8243m2, with the area of the proposed new development
utilising the entirety of the site. The proposed development for a highway service centre includes
the service station bowsers, fast food outlet, service station, children’s play area, services, truck
parking and associated carparking and landscaped areas.
A Site Plan is located in Appendix A for further detail.
3.0 WATER QUALITY AND TREATMENT OBJECTIVES
This SMP will demonstrate how the proposed stormwater management strategy complies with the
requirements of the Noosa Shire Council (NSC) and the State Planning Policy (2014), in terms of
demonstrating how the relevant stormwater pollutant reduction objectives will be met. Discharge
from the site must achieve pollutant load reduction targets (Table 1) and be demonstrated through
use of the appropriate modeling software.
Table 1 – Pollutant Reduction Targets for South East Queensland
Pollutant Type Reduction Objective
Total Suspended Solids (TSS) 80% reduction in average annual load of pollutants
Total Phosphorus (TP) 60% reduction in average annual load of pollutants
Total Nitrogen (TN) 45% reduction in average annual load of pollutants
Gross Pollutants (GP) 90% reduction in average annual load of pollutants
Covey Associates Pty Ltd 2 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 7
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
3.1 Water Quality Objectives
The nearest water course to the site is the North Maroochy River and is located within the
Maroochy River Basin Catchment Plan. The Environmental Protection Water Policy 2009 South
East Queensland Map Series (Plan WQ1411) identifies North Maroochy River to be lowland
freshwaters. Table 2 outlines the specific performance criteria required within lowland freshwaters
in the Maroochy River Basin Environmental Values and Water Quality Objectives – Basin No. 141
(part) including all tributaries of the Maroochy River (Department of Environment and Resource
Management, 2010).
Table 2 – Site Stormwater Quality Objectives
Pollutant Water Quality Objectives
Lowland Freshwater Values
Suspended Solids (SS) <6 mg/L (annual mean concentration)
Total Phosphorus <50 µg/L (annual mean concentration)
Total Nitrogen <500 µg/L (annual mean concentration)
Turbidity <10 NTU
Aim for no visible oils, petrochemicals, films
Hydrocarbons
or odours
Dissolved Oxygen 85 – 110 % saturation
Chlorophyll-a 5 µg/l
pH 6.5 – 8.0
Litter Aim for no anthropogenic material greater
than 5 mm in any dimension.
3.2 Area of Treatment
The total area of the site to be treated is approximately of 8243 m2. The site has been modelled as
one (1) catchment. The catchment consists of the north exit point, south entrance and exit road,
car and truck parking, service area and food outlets and the landscaped areas. Refer to the Site
Plan in Appendix A for further details.
3.3 Non-treatment Areas
The southern entry/exit point at the site onto Taylor court is unable to be treated due to the site
topography. This area comprises 673 m2 of the site and is not considered likely to cause adverse
impacts to the surrounding environment due to its small area. This area has been included within
the model as untreated road and untreated landscaping area. Refer to Figure 3 for details on the
untreated area.
Covey Associates Pty Ltd 3 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 8
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Treated Area
Untreated Area
Figure 3 Catchment Areas
4.0 WATER QUALITY MODELLING ASSESSMENT/APPROACH
4.1 Scenario Methodology
The site was modelled using split catchment source nodes, comprised of roof area, road area and
groundcover nodes. The hardstand area of pavement and play-park has been modelled as
groundcover at 100% impervious. The stormwater treatment proposed for the site consists of one
(1) bioretention basin.
The runoff within the area beneath the service station bowser canopy will be captured by a grated
channel surrounding the area and directed to a holding tank. This will reduce the risk of any
potential runoff containing hydrocarbons entering the stormwater network in the event of a spill.
The holding tank will be monitored and emptied when required, particularly prior to a large rain
event. Roof Runoff from the canopy will be directed to the bioretention basin for treatment.
Refer to Stormwater Quality Management Plan in Appendix B.
4.2 MUSIC Model Parameters
The MUSIC Modelling Guidelines – South East Queensland Version 1.0 (2010) was used to
source base and storm flow concentrations and runoff generation. The model was calibrated using
the Bureau of Meteorology (BOM) data from Cooroy Composite, 1973 - 1983, at a 6-minute time
step. This is in accordance with Water by Design’s MUSIC Modelling Guidelines – South East
Queensland Version 1.0 (2010). All source nodes were set up in accordance with this guideline,
specifically for split catchments. The source nodes were set up as ‘commercial’ due to the site
characteristics being similar to those in a commercial area. No routing of drainage links was
adopted for the purpose of taking a conservative approach. This approach assumes that the flow
through the drainage system takes no time, which over estimates the likely pollutant load.
4.3 Land Use/Source Node Areas.
The proposed development has been treated as one (1) catchment. The catchment has further
been divided into contributing roof, landscaping, hardstand and road area. Refer to Table 3 for
details. A MUSIC model concept map is located in Appendix C.
Covey Associates Pty Ltd 4 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 9
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Table 3 – MUSIC Source Node Attribute Summary
Area
Source Node
(ha)
Roof 0.096
Road 0.437
Landscaping 0.181
Hardstand 0.042
Untreated Road 0.054
Untreated Landscaping 0.013
Total 0.823
4.4 Proposed Stormwater Treatment Train
The development has been modelled as one (1) catchment with the following mitigation measures
proposed. Refer to Stormwater Management Plans in Appendix B for details.
Stormwater runoff from the site will be treated by a Bioretention Basin prior to discharge off site.
Refer to Table 4 for bioretention basin sizing. Filter media is established to a depth of 0.5 m, with a
0.1 m and 0.2 m transition and drainage layer, respectively. The extended detention depth is 0.3
m.
Table 4 –Type and Size of Stormwater Treatment Device
Stormwater Treatment Device Detail
Catchment 1
Bioretention basin 115 m2 Surface Area, 115 m2 Filter Area
4.5 Pollutant Reduction Results
MUSIC modelling of the proposed stormwater treatment strategy for the site was performed to
ensure the identified load based pollutant reduction objectives were achieved. MUSIC version 6.2
has been used to model the effectiveness of the designed stormwater treatment trains.
The target reductions in stormwater pollutants are based on a comparison of an unmitigated
scenario i.e. having no treatment on site, and the mitigated scenario, which has stormwater
treatment measures incorporated into the site. The results of the MUSIC models for the each
catchment and the overall site can be found in Table 5 and demonstrate that compliance has been
met or exceeded for all the required pollutant load reduction objectives stated in the State Planning
Policy (2014) at catchment and site level.
Table 5 – MUSIC Results –Treatment Train Effectiveness
Reduction Target
Unmitigated Mitigated
Pollutant Achieved Reduction Compliance
(kg/yr) (kg/yr)
(%) (%)
TSS 3380 687 80 80 Y
TP 6.54 1.61 75 60 Y
TN 35.3 14.8 58 45 Y
GP 234 19.7 92 90 Y
As the results in Table 5 demonstrates, the stormwater quality management strategies proposed
for the proposed Highway Service Station meet or exceed the target reduction rates required by
the NSC and the State Planning Policy (2014).
Covey Associates Pty Ltd 5 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 10
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
5.0 MAINTENANCE PERIOD
5.1 Bioretention Basin
The proposed bioretention basin will require consideration and management during both the
construction and operational phases of the development. In order to establish vegetation and
treatment functions in the bioretention system, the filter media must be protected from pollutants
commonly generated in the construction phases. During the operational phase, regular
maintenance of bioretention system is required to ensure comprehensive vegetation
establishment, a critical component in stormwater pollutant uptake. Below are details on the
general maintenance periods and requirements for the construction and operational periods.
5.1.1 Maintenance During ‘Construction Phase’
Erosion and sediment control devices will be installed at the commencement of all the staged
works to capture and treat runoff during construction works. The sediment control devices should
be cleaned out as required and at the end of the works. During the construction stage, all sediment
control devices are to be inspected weekly, after runoff generating rain events and prior and after
prolonged site shut downs (e.g. holiday periods).
Following construction of the roadways and buildings on site the basin will be constructed to the
final design and filter media layers and plants will be installed. Leaving the completion of the
bioretention basin until after construction is completed will prevent any potential clogging of the
system during the construction period.
6.0 STORMWATER QUANTITY
The proposed stormwater quantity management for this site ensures non-worsening of flows as a
result of the proposed development. Development of the site will result in an increase in
impervious area and a corresponding increase in peak stormwater runoff rates which will be
mitigated through on-site detention. This section of the report encompasses the hydrological and
hydraulic analysis for the proposed development and identifies the stormwater detention measures
required to ensure non-worsening conditions.
6.1 Stormwater Quantity Management
An analysis of the stormwater (quantity) required for the site, involved the following processes:
Determining the overall catchment areas contributing to flow from the proposed development
site;
Calculating the 1%, 10% and 39% Annual Exceedance Probability (AEP) peak discharges
using XP-RAFTS for existing case;
Rational method calculations for comparison and calibration of the XP-RAFTS runoff model
to ensure the accuracy of results; and
XP-RAFTS detention modelling for the 1%, 10% and 39% AEP design discharges to
demonstrate that peak discharges are mitigated in the developed case and flows leaving the
site are ‘non-worsening’.
6.2 Hydrology (XP-RAFTS)
XP-RAFTS was utilised to determine the peak stormwater discharges for the subject site for pre-
development and post-development scenarios.
Covey Associates Pty Ltd 6 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 11
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
The proposed development site has an area of 0.824 ha. The site receives a very small upstream
catchment which when combined with the site area gives a total area of 0.924 ha. The majority of
this upstream area is a landscaping buffer between the site and Holts Road.
6.3 XP-RAFTS Data
6.3.1 Model Scenarios
The existing and proposed conditions for the 1%, 10% and 39% AEP events were modelled in XP-
RAFTS to determine the peak stormwater flows for the site.
The three scenarios modelled for this investigation are:
CSS_E01b - represents the existing characteristics of the subject site (pre-development);
CSS_D01b - represents the subject site as fully developed (no detention); and
CSS_M01b - represents the subject site as fully developed and the effects of the proposed
detention tank.
6.3.2 Rainfall Intensities
The rainfall intensities used in XP-RAFTS are typical to Cooroy and were generated from the
Bureau of Meteorology’s online IFD data website (accessed 30 May 2016). The rainfall intensity
tables are contained in Appendix E.
6.3.3 Existing and Proposed Development Areas
The total catchment area has been modelled as one (1) catchment. The existing and proposed
catchment boundaries are the same for each modelling scenario. Refer to Figure 5 for the
stormwater quantity catchment boundary. Refer to Appendix D for a detailed Stormwater Quantity
Catchment Plan.
Figure 5 Stormwater Quantity Catchment Boundaries
6.3.4 Initial and Continuing Losses
Initial and Continuing Rainfall Loss parameters were adopted as per Table 6.
Covey Associates Pty Ltd 7 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 12
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Table 6 – Initial and Continuing Losses
Pervious Catchments Impervious Catchments
Initial Loss Cont. Loss Initial Loss Cont. Loss
Event (mm) (mm/hr) (mm) (mm/hr)
AEP 1% 0 2.5 0 0
AEP 10% and 39% 12.5 2.5 0 0
6.3.5 Pervious and Impervious Areas
The proposed development site and external catchment in its existing state has a total area of
0.924 ha and is completely pervious.
The proposed development and external catchment has a total area of 0.924 ha and a proposed
impervious area of 0.63 ha for the developed case, equating to 62%. This will increase total
contributing catchment’s percentage impervious from 0% to 62%.
All pervious and impervious areas for the existing and developed scenarios are detailed in Table 7.
Table 7 – Existing and Developed Catchment Areas and Slopes
Catchment Area Pervious Impervious Slope
(ha) (ha) (ha) (%)
Existing
Site 0.92 0.92 0 5
Developed
Site 0.92 0.29 0.63 5
The stormwater quantity catchment boundaries are shown in Appendix D.
6.3.6 Manning’s Values
Manning’s values varied due to the differing catchment characteristics / land uses and were
applied independently to the catchment. The values were generally adopted as follows:
Pervious Area, n = 0.032; and
Impervious Area, n = 0.018.
6.3.7 Catchment Slope
The Equal Area method was used to determine the catchment slope, which is summarised in
Table 7. The catchment slope in the developed case is unchanged from the existing case scenario.
6.3.8 Storm Durations
Standard storm durations of 15, 20, 25, 30, 45 60 and 90 minutes were modelled to estimate the
peak discharge.
6.4 Calibration
6.4.1 Rational Method
Rational Method calculations were undertaken for the site for calibration of the existing case XP-
RAFTS model – Table 8.
Covey Associates Pty Ltd 8 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 13
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Variable Value Units
Area: 0.924 ha
Tc 5.9 minutes
C10 0.68 fraction
Table 8 - Rational Method Calculations
Variable 1% AEP 10% AEP 39% AEP
Freq Factor 1.2 1.0 0.85
Intensity (mm/hr) 299.5 205.2 149.1
Discharge (m3/s) 0.628 0.358 0.221
The Rational Method Calculations for the 1%, 10% and 39% AEP events generally reflect results
from the XP-RAFTS model. Thus, the XP-RAFTS peak flows have been adopted for hydrological
modelling and detention sizing purposes. A comparison of the results is provided in Table 9.
Table 9 - XP-RAFTS and Rational Method Comparison
Rational XP-RAFTS Difference
AEP (m3/s) (m3/s) (%)
1% 0.628 0.630 0.4
10% 0.358 0.357 -0.4
39% 0.221 0.219 -1.1
6.5 Design Discharges Unmitigated
6.5.1 Peak Durations
Temporal patterns from Australian Rainfall and Runoff, Volume 2, (1987) have been adopted for
each storm duration. A range of storm durations were analysed to determine the peak discharge
for the catchment. Table 10 presents the flows generated using XP-RAFTS from design storms at
the proposed development site for the existing and developed (unmitigated) case scenarios.
Table 10 - XP-RAFTS Design Discharges (Unmitigated)
Existing Developed
Peak Peak
Critical Critical
Catchment AEP Flow Flow
Duration Duration
(m3/s) (m3/s)
1% 25 min 0.630 15 min 0.724
Outlet 10% 60 min 0.357 25 min 0.518
39% 60 min 0.219 25 min 0.331
The peak flows discharging from the site have increased in the developed case scenario due to the
resulting increase in impervious area. To reduce the flows to meet non-worsening conditions, a
detention tank is proposed to increase detention capacity on site and reduce the offsite flows.
6.6 Stormwater Detention
The pre-developed and post-developed (mitigated) conditions were modelled in XP-RAFTS to
demonstrate that stormwater flows will not be increased with the inclusion of an appropriately
designed storage device. The increases in peak flows have been mitigated on site through the use
of a detention tank. Detention provided by the bioretention basin to treat water quality will also be
utilised on site.
Covey Associates Pty Ltd 9 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 14
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Refer to Site Plans in Appendix B for the proposed detention tank location and details.
6.6.1 Detention Tank
The flows up to 39% AEP will be directed to and will be detained within the proposed bioretention
basin and flow greater than the 39% AEP will be detained within the detention tank located at the
lowest point of the site in the south western corner. A diversion chamber prior to the bioretention
basin inlet will divert all flow above a 39% AEP event to the detention tank. Refer to Stormwater
Management Plan in Appendix B. The bioretention basin has a storage component 1.25 m deep
with a surface area of 115 m2, providing a storage volume of 143.75m3. The proposed detention
tank dimensions are approximately 5 m wide x 10 m long x 2 m high providing a maximum
detention volume of 100 m3. The combined detention volume provided between the bioretention
basin and the detention basin is 243.75 m3 with a minimum available depth of about 2.7 m. The
required detention is 171m3 peaking at a depth of 2.12 m in the 1% AEP event. The tank will slow
release via one (1) 325 mm orifice plate and a weir 1.5 m high and 0.45 m wide discharging into a
chamber and connecting to an existing stormwater network on site. Refer to the Stormwater
Management Plan in Appendix B for detail.
Table 11 summarises stormwater flows, storage volumes and stage height for the required
detention tank.
Table 11 - Post-Development Conditions – XP-RAFTS
Stormwater Flows for proposed detention basin
Basin Peak
Basin Inflow Peak Depth
Basin AEP Outflow Storage
(m3/sec) (m3/sec) (m) (m3)
1% 0.724 0.624 2.12 171
Det_tank 10% 0.518 0.349 1.78 122
39% 0.331 0.211 1.45 73
XP-RAFTS modelling predicts that the proposed detention tank will reduce the post-development
peak stormwater flows for all critical storm events. Refer to Table 12 below for detail.
Table 12 - Comparison of Pre & Post-Development (mitigated) Stormwater flows in XP-RAFTS
Existing Mitigated
Catchment AEP Critical Peak Flow Critical Peak Flow
Duration (m3/s) Duration (m3/s)
1% 25 min 0.630 25 min 0.624
Site Area 10% 25 min 0.357 25 min 0.349
39% 60 min 0.219 25 min 0.211
7.0 CONCLUSIONS AND RECOMMENDATIONS
As described in Table 5, the stormwater treatment measures selected for the proposed
development achieve the performance criteria set by the NSC and by the State Planning Policy
(2014). Annual load reductions of TSS, TP and TN between the unmitigated and mitigated MUSIC
model scenarios have been met or exceeded. It is considered that a conservative approach has
been taken as no routing in the drainage links has been adopted.
This site based SWMP has demonstrated that the proposed development, when incorporating the
proposed detention strategies, can be undertaken with non-worsening to the quantity of runoff to
downstream environments.
Covey Associates Pty Ltd 10 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 15
STORMWATER MANAGEMENT PLAN
Client: Hass Holdings ATF The Quasar Trust Location: Taylor Court, Cooroy
Sufficient consideration of stormwater controls has been demonstrated by:
Compliance with QUDM (2013)
Compliance with the requirements of Noosa Shire Council’s Load Based Objectives
Compliance with the State Planning Policy (2014)
Compliance with the EPP (Water) 1997
Ecological sustainability in terms of the development’s impact upon receiving waters and the
viability of the proposed site development.
The measures proposed within this report to manage stormwater quality and quantity achieve the
nominated requirements of NSC and the State Planning Policy (2014). This preliminary design of
the quality and quantity management measures is based on the current and best-practice
principles.
REFERENCES
Department of Environment and Resource Management (2010) Environmental Protection (Water)
Policy 2009 – Maroochy River Environmental Values and Water Quality Objectives Basin No,
141 (part) including all tributaries of the Maroochy River
Department of State Development, Infrastructure and Planning (2014) State Planning Policy,
Brisbane, Queensland.
Institute of Public Works Engineering Australia, Queensland Division Ltd (2013) Queensland Urban
Drainage Manual, Third Edition.
Noosa Shire Council (2013) The Noosa Plan
Water by Design (2010) MUSIC Modelling Guidelines – South East Queensland, Version 1.
Water by Design (2014) Bioretention Technical Design Guidelines, Version 1.1.
Covey Associates Pty Ltd 11 Project No: 161968
Consulting Engineers 100415 Rpt Iss A
Page 16
APPENDIX A SITE LAYOUT PLAN
Page 17
1
DA-05
H O L T S R O A D
SITE BOUNDARY 122° 10' 50" 75.04m 120° 48' 20" 28.239m
SITE BO
5,000
S2 S1
LANDSCAPING
SETBACK
10,000
210° 48' 40"
UNDAR ONE WAY
Y
27.134m
1 13
EXIT
6,400
CARPARK
WAITING BAY
2,700
L O T 1 L O T 3 14 22
SITE BOU
9No CYLCLE
PARKING 23 4,000
K
SETBAC
NDARY
OUTDOOR 5,000
T A Y L
DINING AREA
2 75 m2
1
DA-07 34 DA-07
202° 08
FOOT P
AIR AND
COLLECT
OVERFLOW
FAST2 FOOD
2,600
FUEL
LANDSCAPING
'
202° 30'
PARKING
ATH
VENTS
LANDSC
WATER
330 m
O R
UNDERGROUND
LANDSC
SERVICE STATION
86.32m
APING
FUEL TANKS
DINING AREA BOWSERS (8No)
APING
1,088 m2
37.233m
180 m2
PAY
C O U R
125 m2
DRIVE THROUGH
133 m2
36
5,000
UNDERGROUND
FUEL TANK
ORDER
ENTRY
T
9,000
EXIT
SERVICE
STATION
2
33
195 m
SALES AREA
PURUSE
120 m2
1 4
SERVICE MOTORCYLCLE
5"
80 m2 PARKING
SERVICE BAY
0' 2
°2
242
UNDERGROUND
m
048
DETENTION TANK
14.
ONE WAY CAPING
WATER LANDS
5,000
TANK 434 m2
BIO RETENTION
BASIN 44.312m
' 10"
WATER 291° 20
TANK PUMP
300° 48' 40" 46.768m
(LOT 1)
BOOSTER
MENT
S EASE
ACCES
1
DA-06
1 SITE PLAN
SCALE - 1:250 -
PRELIMINARY HIGHWAY SERVICE
ISSUE DATE BY DESCRIPTION CHKD
P1 23.05.2016 RP PRELIMINARY PW
reddogarchitects.com
P2
P3
25.05.2016
31.05.2016
RP
RP
PRELIMINARY
PRELIMINARY
PW
PW
STATION, COOROY
P 07 3252 8912 F 07 3252 8914 P4 31.05.2016 RP PRELIMINARY PW PROJECT NO. DRAWING NO. ISSUE
[email protected]
2480-276 DA-02 P4
Page 18
APPENDIX B STORMWATER QUALITY MANAGEMENT PLANS BY COVEY ASSOCIATES
Page 19
S2 S1
LANDSCAPING
ONE WAY
1 13
CARPARK EXIT
WAITING BAY
LOT 1 LOT 3 14 22
9No CYLCLE
PARKING 23
OUTDOOR
DINING AREA
34
ATH
WATER
COLLECT
OVERFLOW
FOOT P
LANDSCAPING FUEL
FAST FOOD
APING
AIR AND
VENTS
PARKING 330 m2
LANDSC
APING
UNDERGROUND
SERVICE STATION FUEL TANKS
BOWSERS (8No)
LANDSC
TAYLOR
DINING AREA
PAY
DRIVE THROUGH
36
COURT
UNDERGROUND
FUEL TANK
ORDER
ENTRY
EXIT
SERVICE
STATION 33
195 m2
SALES AREA
PURUSE
120 m2
1 4
SERVICE MOTORCYLCLE
80 m2 SERVICE BAY PARKING
D
GROUN
UNDER K
E TE N TION TAN
D
(5x10x2)
CAPING
LANDS
WATER ONE WAY
TANK
WATER
TANK PUMP
BOOSTER
OT 1)
EASE MENT (L
ACCESS
Consulting Civil & PROPOSED SERVICE 161968 SWMP01
Structural Engineers STORMWATER CENTRE TAYLOR COURT, A
Project Management MANAGEMENT LAYOUT PLAN HASS HOLDINGS ATF, COOROY,
ASSOCIATES PTY LTD
APPROVAL
& Planning THE QUASAR TRUST QUEENSLAND
Page 20
UN
DE
FU RG
E RO
LEGEND L
TA UN
NK D
03
SW A
MP
B
SW
MP0
3
30
MP
SW C
0 3
MP
A
SW
B
SW
MP
C
03
Consulting Civil & PROPOSED SERVICE 161968 SWMP02
Structural Engineers CONCEPT BIO-BASIN AND CENTRE TAYLOR COURT, A
Project Management DETENTION TANK LAYOUT HASS HOLDINGS ATF, COOROY,
ASSOCIATES PTY LTD
APPROVAL
& Planning PLAN THE QUASAR TRUST QUEENSLAND
Page 21
SECTION A-A
SECTION B-B SECTION C-C
Consulting Civil & PROPOSED SERVICE 161968 SWMP03
Structural Engineers CONCEPT BIO-BASIN AND CENTRE TAYLOR COURT, A
Project Management DETENTION TANK DETAILS HASS HOLDINGS ATF, COOROY,
ASSOCIATES PTY LTD
APPROVAL
& Planning PLAN THE QUASAR TRUST QUEENSLAND
Page 22
APPENDIX C MUSIC CONCEPT MAP
Page 23
Hardstand Untreated untreated road [Mixed] Landscaping
Page 24
APPENDIX D STORMWATER QUANTITY CATCHMENT PLANS
Page 25
| Cooroy Service Centre Appendix D | Catchment Boundary Plan mY Ye SMM 0 25 _* O:\0JOBS\16\161968\GIS\MapIinfo\Maps\PDF\161968-0001A_CatchmentBoundaries.wor
Page 26
APPENDIX E RAINFALL DATA, RATIONAL METHOD DATA AND RESULTS
Page 27
Rational Method Data
Location: Cooroy
Australian Rainfall & Runoff IFD Coefficents
2I 2I 2I 50I 50I 50I F2 F50 G
1 12 72 1 12 72
50.33 10.62 3.48 91.03 24.96 8.8 4.39 17.57 0.13
Rainfall Intensity (mm/hr)
DURATION AVERAGE RECURRENCE INTERVAL (years)
hours minutes 1 2 5 10 20 50 100 200 500
0.08 5 124 158 195 217 247 286 317 347 389
0.10 6 116 148 184 204 232 269 298 327 366
0.17 10 96 122 151 168 191 222 246 270 303
0.25 15 80 102 127 141 161 187 207 228 255
0.33 20 70 89 111 124 141 164 182 200 224
0.42 25 63 80 100 111 127 147 163 180 202
0.5 30 57 73 91 101 116 135 149 164 184
0.75 45 45.9 59 73 82 94 109 121 133 150
1 60 39.1 50 63 70 80 93 103 114 128
1.5 90 30.3 39.0 49.7 56 65 76 85 94 106
2 120 25.2 32.6 42.0 47.7 55 66 74 82 93
3 180 19.4 25.2 33.1 38.0 44.4 53 60 67 77
4.5 270 14.9 19.5 26.1 30.2 35.6 43.0 48.8 55 63
6 360 12.3 16.3 22.0 25.7 30.4 37.0 42.2 47.6 55
9 540 9.50 12.6 17.4 20.4 24.4 29.9 34.4 39.0 45.6
12 720 7.89 10.5 14.7 17.4 20.9 25.8 29.7 33.9 39.8
18 1080 6.20 8.29 11.6 13.9 16.7 20.7 23.9 27.3 32.1
24 1440 5.23 6.99 9.87 11.8 14.2 17.6 20.4 23.4 27.6
30 1800 4.56 6.11 8.66 10.3 12.5 15.6 18.0 20.7 24.4
36 2160 4.07 5.46 7.76 9.28 11.2 14.0 16.2 18.6 22.1
48 2880 3.38 4.54 6.49 7.79 9.46 11.8 13.7 15.8 18.7
72 4320 2.55 3.44 4.95 5.97 7.27 9.12 10.6 12.2 14.5
Catchment Data
Variable Value Unit
Area 0.9241 ha
C10 0.68 fraction
tc 5.9 minutes
Rational Results
AVERAGE RECURRENCE INTERVAL (years)
Variable 1 2 5 10 20 50 100
Freq Factor 0.544 0.578 0.646 0.68 0.714 0.782 0.816
Intensity (mm/hr) 117.1 149.1 184.6 205.2 233.6 270.9 299.5
Discharge (m3/s) 0.164 0.221 0.306 0.358 0.428 0.544 0.628
[OCR of page images]
Rational Method Data
Location: Cooroy
Australian Rainfall & Runoff IFD Coefficents
ah 2h 2l72 50], 5012 50172 F2 F50 G
50.33 10.62 3.48 | 91.03 | 24.96 8.8 4.39 17.57 0.13
Rainfall Intensity (mm/hr
DURATION AVERAGE RECURRENCE INTERVAL (years)
hours minutes 1 2 5 10 20 50 100 200 500
0.08 5 124 158 195 217 247 286 317 347 389
0.10 6 116 148 184 204 232 269 298 327 366
0.17 10 96 122 151 168 191 222 246 270 303
0.25 15 80 102 127 141 161 187 207 228 255
0.33 20 70 89 111 124 141 164 182 200 224
0.42 25 63 80 100 111 127 147 163 180 202
0.5 30 57 73 91 101 116 135 149 164 184
0.75 45 45.9 59 73 82 94 109 121 133 150
1 60 39.1 50 63 70 80 93 103 114 128
1.5 90 30.3 39.0 | 49.7 56 65 76 85 94 106
2 120 25.2 32.6 | 42.0 47.7 55 66 74 82 93
3 180 19.4 25.2 | 33.1 38.0 44.4 53 60 67 77
45 270 14.9 19.5 | 26.1 30.2 35.6 43.0 48.8 55 63
6 360 12.3 16.3 | 22.0 25.7 30.4 37.0 42.2 47.6 55
9 540 9.50 12.6 17.4 20.4 24.4 29.9 34.4 39.0 45.6
12 720 7.89 10.5 14.7 17.4 20.9 25.8 29.7 33.9 39.8
18 1080 6.20 8.29 11.6 13.9 16.7 20.7 23.9 27.3 32.1
24 1440 5.23 6.99 | 9.87 11.8 14.2 17.6 20.4 23.4 27.6
30 1800 4.56 6.11 8.66 10.3 12.5 15.6 18.0 20.7 24.4
36 2160 4.07 5.46 | 7.76 9.28 11.2 14.0 16.2 18.6 22.1
48 2880 3.38 4.54 | 6.49 7.79 9.46 11.8 13.7 15.8 18.7
72 4320 2.55 3.44 | 4.95 5.97 7.27 9.12 10.6 12.2 14.5
Catchment Data
Variable | Value Unit
Area 0.9241 ha
Cio 0.68 fraction
te 5.9 minutes
Rational Results
AVERAGE RECURRENCE INTERVAL (years
Variable 1 2 5 10 20 50 100
Freq Factor 0.544 | 0.578 | 0.646 | 0.68 0.714 | 0.782 | 0.816
Intensity (mm/hr) 117.1 | 149.1 | 184.6 | 205.2 | 233.6 | 270.9 | 299.5
Discharge (m°/s) 0.164 | 0.221 | 0.306 | 0.358 | 0.428 | 0.544 | 0.628