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Attachment 6 - Stormwater Management Plan
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Log in to see the plans as drawn NOOSA LANDFILL –
STORMWATER MANAGEMENT PLAN
CLIENT: NOOSA SHIRE COUNCIL
DOCUMENT NUMBER: R2015
VERSION: B
DATE: 7/2/2022
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
TABLE OF CONTENTS
1 INTRODUCTION 1
1.1. OBJECTIVE & SCOPE 1
1.2. GUIDELINES 2
1.3. LEGAL REQUIREMENTS 2
1.4. LICENSE CONDITIONS AND WATER QUALITY OBJECTIVES 3
1.5. PRINCIPLES OF SURFACE WATER MANAGEMENT FOR THE SITE 4
1.6. DRAINAGE CONTROL 4
1.6.1. CLEAN WATER DIVERSION 5
1.6.2. DIRTY WATER DRAINAGE 5
1.7. SEDIMENT CONTROL. 5
1.8. EROSION CONTROL 5
2 SITE DESCRIPTION 6
2.1. LOCATION AND OPERATIONS 6
2.2. TOPOGRAPHY 6
2.3. CLIMATE 7
2.4. MASTERPLAN 7
3 EXISTING STORMWATER MANAGEMENT 9
3.1. RECOMMENDATIONS FOR CURRENT STORMWATER MANAGEMENT 9
4 PROPOSED STORMWATER MANAGEMENT 10
4.1. SOUTHERN CATCHMENT (SW5) 10
4.2. NORTHERN CATCHMENT (SW2 & SW4) 10
4.2.1. MANAGEMENT OF NUTRIENTS FROM GREEN WASTE AREA 12
4.2.2. DETAILED DESIGN 12
5 SITE INSPECTION AND MONITORING 13
6 REFERENCES 14
APPENDIX A STORMWATER STAGING AND OPTIONS PLANS 15
APPENDIX B SW5 DESIGN REPORT 16
APPENDIX C CONCEPT EROSION AND SEDIMENT CONTROL PLAN 17
APPENDIX D SW2 HES BASIN CONCEPT SIZING 18
TABLE OF FIGURES
FIGURE 1 - SITE LOCALITY PLAN (SOURCE GOOGLE) ...................................................................................................................................................................... 1
FIGURE 2 – AERIAL PHOTOGRAPHY AND DISTURBED AREAS (SOURCE: NEARMAPS, IMAGE DATE 13-11-21) ..............................................................6
FIGURE 3 –AVERAGE ANNUAL RAINFALL FOR EUMUNDI CRESCENT ROAD ......................................................................................................................... 7
FIGURE 4 – MASTERPLAN YEARS 1-5 (SOURCE: ATC WILLIAMS) ................................................................................................................................................. 7
FIGURE 5 – MASTERPLAN YEARS 6-10 (SOURCE: ATC WILLIAMS) ..............................................................................................................................................8
FIGURE 6 – EXISTING DRAINAGE REGIME...........................................................................................................................................................................................9
FIGURE 7 – EXISTING HES BASIN OUTLET AND FLOOD LEVELS ................................................................................................................................................ 10
FIGURE 8 – NORTHERN OUTFLOWS (PROPOSED HES BASIN) ....................................................................................................................................................11
FIGURE 9 – PROPOSED HES BASIN OUTLET AND FLOOD LEVELS ............................................................................................................................................ 12
FIGURE 10 – FLOATING WETLAND INSTALLED AT SCC LANDFILL ............................................................................................................................................ 12
TABLE OF TABLES
TABLE 1 – SURFACE WATER RELEASE LIMITS .....................................................................................................................................................................................3
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
1 INTRODUCTION
Topo was engaged by Noosa Shire Council (NSC) to prepare a Stormwater Management Plan (SMP) for the Noosa
Landfill. The site is located on Eumundi-Noosa Road as illustrated in Figure 1.
The site currently operates under the Environmental Authority Permit No. EPPR01855314 and is licensed to carry out the
following environmentally relative activities (ERA):
+ ERA 33 – Crushing, milling, grinding or screening > 5000t per year
+ ERA 60-(1a) – Waste disposal facility < 50,000t/yr
Figure 1 - Site Locality Plan (Source Google)
1.1. OBJECTIVE & SCOPE
The objective of this report is to provide an Operational Stormwater Management Plan for the developed Master Plan
and construction staging. The Masterplan includes the augmentation of existing landfill cells as well as the construction
of new cells within the landfill site. Further details are provided throughout this report.
The objective of this SMP is to:
+ Develop a formalised drainage and sediment control strategy that complies with the requirements of the
Guideline Stormwater and environmentally relevant activities (DES, 2021), and the Environmental Authority Permit
No. EPPR01855314
This report addresses surface water only and does not include the management of groundwater or leachate.
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1.2. GUIDELINES
This SMP has been prepared in accordance with:
+ Guideline Stormwater and environmentally relevant activities (DES, 2021)
+ Best Practice Erosion and Sediment Control (IECA, 2008), and
+ Queensland Urban Drainage Manual (QUDM) (IPWEAQ, 2016)
In addition to these documents, reference has been made to the Noosa Landfill – Operational Phase Stormwater
Management Plan prepared by O2 (O2, 2013).
1.3. LEGAL REQUIREMENTS
Stormwater runoff has the potential to cause water contamination and/or environmental harm and is regulated under
the EP Act. Some of the key legal requirements relevant to the operation of the landfill include:
+ Where stormwater conditions appear on an environmental authority, it is an offence under s.430 of the EP Act,
to not comply with the conditions of approval. This includes anyone operating under the environmental
authority e.g. contractors, consultants etc.
+ Causing serious or material environmental harm is an offence under s.437 and s.438 of the EP Act respectively.
+ It is an offence to cause an environmental nuisance under s.440. Environmental nuisance is unreasonable
interference with an environmental value. It may also include an unhealthy, offensive or unsightly condition
because of contamination.
+ Under s.440ZG it is an offence to unlawfully deposit a prescribed water contaminant to waters. The most
common prescribed contaminants resulting from poor stormwater management of ERA operations are:
o o chemical, or chemical waste
o ashes, clay, gravel, sediment, stones and similar organic or inorganic matter
o building and construction materials
o building, construction and demolition waste
o industrial waste
o oil
o putrescible waste, and
o waste water.
+ Under s.319 an obligation is placed upon all persons in Queensland who are carrying out activities which may
cause environmental harm to comply with the ‘general environmental duty’. This requires that all reasonable
and practicable measures must be adopted to prevent and minimise environmental harm. Although not being
able to demonstrate compliance against the general environmental duty is not an offence, demonstrating that
all reasonable and practicable measures have been adopted is a defence for offences such as water
contamination (DES, 2021).
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
1.4. LICENSE CONDITIONS AND WATER QUALITY OBJECTIVES
The following conditions specified by the site permit (Permit No. BRID0056) relate, directly or indirectly, to the
management of stormwater:
WT1 – Site erosion protection measures and sediment control measures must be implemented and must have the
hydraulic effectiveness to treat stormwater for 90% of the annual runoff for each stormwater catchment.
Where soils are temporarily exposed for the construction of new facilities or to facilitate changes in landfill design, all
reasonable and practical measures must be implemented to minimise the amount of sediments able to discharge from
the site. As a minimum the following design criteria apply:
1. Collect and drain stormwater from disturbed soils to a sediment basin sized to contain an 80 th% five-day event
or similar; and
2. The design life and design storm for temporary drainage works to convey waters to the sediment basin and
around disturbed areas are:
a. Disturbed area open < 12 months – 1 in 2-year ARI event plus 150mm freeboard
b. Disturbed area open 12-24 months – 1 in 5-year ARI event plus 150mm freeboard
c. Disturbed area open > 24 months – 1 in 10-year ARI event plus 150mm freeboard
d. Temporary culvert crossing – minimum 1 in 1-year ARI hydraulic capacity
WT2 - The release of collected and treated stormwater to waters, from areas of the site not likely to be contaminated
with waste materials, must be in accordance with Table 2 – compliance limits for controlled releases of treated stormwater
to surface waters
Note: Table 2 is reproduced below as Table 1.
Table 1 – Surface Water Release Limits
QUALITY
RELEASE POINT RELEASE LIMIT LIMIT TYPE MONITORING FREQUENCY
CHARACTERISTICS
pH 6.5 - 9.0 Range
Specific Conductance
1500 Maximum Commencement of Release then weekly
(µS/cm)
thereafter. If no release occurs, no
Dissolved Oxygen (mg/L) 6 Minimum sampling is required.
Total and Dissolved
N/A Maximum
Aluminium (mg/L)
Commencement of Release then weekly
W1 thereafter for a minimum of 5 events
and until a reliable TSS:NTU correlation
Suspended Solids (mg/L) 50
is established and agreed in writing by
the administering authority. If no release
occurs, no sampling is required.
The established The NTU value
correlation of that correlates to Commencement of Release then weekly
Turbidity (NTU) turbidity with total 50mg/L TSS with thereafter. If no release occurs, no
suspended solids a correlation R sampling is required.
(TSS) value of 0.9
WT3- Monitoring of contaminant releases from release point W1 must be undertaken in accordance with the condition
WT2.
WT4 - In addition to WT2, released to waters must not:
1. have any other properties and content concentration causing environmental harm
2. produce any slick or other visible evidence of oil or grease, nor contain visible floating oil, grease, scum, litter or
other visually objectionable matter.
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1.5. PRINCIPLES OF SURFACE WATER MANAGEMENT FOR THE SITE
Ongoing soil and water management will be required through the life of the project. The three cornerstones of the
erosion and sediment control industry are drainage control, erosion control, and sediment control. The primary function
of each of these principles is summarised below:
+ Drainage control measures aim to prevent or reduce soil erosion caused by concentrated flow-including the
management of rill and gully erosion and to appropriately manage the movement of "clean" and "dirty" water
through the site.
+ Erosion control measures aim to prevent or reduce soil erosion caused by raindrop impact and sheet flow (i.e.
the control of splash and sheet erosion)
+ Sediment control measures aim to trap and retain sediment either moving along the land surface (bed load) or
contained within flowing water (suspended sediment) (IECA, 2008).
The proper management of stormwater is critical to the implementation of effective erosion and sediment control. The
effective management of stormwater lies in the appropriate control of runoff velocities and volume.
1.6. DRAINAGE CONTROL
The primary function drainage controls are to:
+ minimise the risk of rill and gully erosion;
+ minimise the risk of hydraulic damage to the adopted erosion and sediment control measures;
+ control the velocity, volume and location of water flow through the site; and
+ appropriately manage the movement of "clean" and "dirty" water through the site (IECA, 2008).
The Guideline - Stormwater and environmentally relevant activities (DES, 2021) requires that high erosion hazard sites
implement the following design and management measures:
+ Erosion protection and sediment control measures should be installed and maintained for all stages of the
activity to minimise erosion and the release of sediments.
+ All areas of soil disturbed and exposed should be managed to minimise the loss of sediment through
revegetation and/or use of other stabilisation techniques.
+ All concentrated stormwater flows (including ‘clean’ stormwater and ‘dirty’ stormwater) should have
concentrated flow paths, such as drainage lines, diversion drains, channels and batter chutes (where applicable)
which have been designed, constructed, effectively armoured and maintained to convey the runoff from events
up to and including the average recurrence interval (ARI) of:
o 1 in 10 year critical duration ARI storm event without causing water contamination, sheet, rill or gully
erosion, sedimentation, or damage to structures or property.
+ Stormwater runoff from external or undisturbed catchments should be diverted around or away from disturbed
areas as much as possible.
+ Sediment basin(s) should be installed and maintained to collect and treat stormwater runoff from all disturbed
areas of the site(s) approved as part of the ERA application, and areas in which any earthen material is stored.
+ For events up to and including a 24 hour storm event with an ARI of 1 in 10 years, the following must be achieved
o a sediment basin must be designed, constructed and operated to retain the runoff at the site(s)
approved as part of the ERA application;
o the release stormwater from these sediment basins must achieve a total suspended solids (TSS)
concentration of no more than 50mg/L for events up to and including those mentioned above.
For events larger than those stated above, all reasonable and practical measures must be taken to minimise the
release of prescribed contaminants.
An alternative basin design (such as a high efficiency basin) can be used provided it has been demonstrated
that the contaminant load to be released to the receiving environment for the life of the project will be equal to
or less than the standard design.
The department supports high efficiency basin technology especially as it may lead to both flexibility
for the site operator and if appropriately designed and managed, sound environmental outcomes.
+ All sediment basins should have a spillway, designed, constructed and effectively armoured to convey
anticipated flows. Design for a 50 year ARI critical event is considered a minimum.
+ Any sediment basin designed in accordance with this list must be operated in such a manner that within 120
hours of the most recent rainfall event, the required design capacity of the upper settling volume is available for
capture and storage of stormwater runoff from the next rainfall event.
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+ In addition to the settling volume requirements, sediment basins should be designed with a sediment storage
zone equal to 50% of the upper settling volume, or the volume of the sediment determined by estimating the
expected sediment runoff volumes over the desired maintenance period of not less than 4 months.
1.6.1. CLEAN WATER DIVERSION
A key component of managing surface waters is the diversion of ‘clean’ runoff away from disturbed portions of the site.
Clean water is defined as water that either enters the property from an external catchment and has not been further
contaminated by sediment within the site, or water that has originated from the site and is of such quality that it does
not need to be treated in order to achieve the required water quality standard, or would not be further improved if it
was to pass through a sediment trap (IECA, 2008).
In diverting clean water around the disturbed portions of the site, it will remain separated from the sediment laden runoff
that requires treatment. It is important that clean water diversion drains are constructed prior to new areas being
disturbed to reduce the likelihood of runoff being contaminated. This management technique has the potential to
greatly reduce the size and operational costs of treatment devices. The clean water drains should be designed to convey
runoff associated with the 10 % Annual Exceedance Probability (AEP) event, in accordance with the Guideline Stormwater
and environmentally relevant activities (DES, 2021).
1.6.2. DIRTY WATER DRAINAGE
Dirty Water Drains (DWD) and diversion bunds are required to convey sediment laden runoff from disturbed areas to
the sediment basin. The dirty water drains will also be designed to convey runoff associated with the 10 year ARI critical
duration event, in accordance with the Guideline Stormwater and environmentally relevant activities (DES, 2021).
1.7. SEDIMENT CONTROL.
To achieve the required release criteria, treatment of dirty site runoff will be required in a Type 1 treatment system. In
accordance with the site permit (Permit No. BRID0056), sediment control measures must be implemented and must have
the hydraulic effectiveness to treat stormwater for 90% of the annual runoff for each stormwater catchment.
1.8. EROSION CONTROL
Erosion control measures aim to prevent or reduce soil erosion caused by raindrop impact and sheet flow. One of the
most effective forms of long term erosion control is the stabilisation of disturbed areas. Where possible, progressive
stabilisation and revegetation of the non–operational areas must be undertaken. If an area is to be non–operational for
only a short duration, temporary measures (such as mulch/compost blankets or jute matting) must be applied.
Temporary stabilisation should also be provided as works are progressing towards the final level, and this can be achieved
through the application of soil binders. Stabilisation of high traffic areas should also be provided, particularly at the truck
unloading points. Stabilisation can be achieved using a layer of crushed concrete, ideally 150 – 200 mm thick or gravel.
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
2 SITE DESCRIPTION
2.1. LOCATION AND OPERATIONS
The Noosa Landfill is located on Eumundi-Noosa Road, Doonan and undertakes a range of waste processing and
resource recovery operations over the site. A portion of the site is finished landfill and has a vegetated surface. Activities
across the site include:
+ waste collection,
+ resource recovery,
+ concrete crushing/recycling,
+ green waste recovery and processing, and
+ oil and paint collection.
The site activities and disturbed areas, as of the 13th November 2021 are illustrated in Figure 2.
Bio Basin
Green Waste
Site Entry Processing
HES Basin
Resource
Recovery Concrete
Processing
Weighbridge
Cell 2.2 -
operational
Figure 2 – Aerial Photography and Disturbed Areas (Source: NearMaps, image date 13-11-21)
2.2. TOPOGRAPHY
The topography varies considerably across the site due to historic landfilling operations. The peak elevations across the
site occur in the central portion of the site (Cell 1.1). All runoff from site is directed to the northern and north-eastern
boundary to discharge points SW2, SW4 and SW5. Details on the existing catchments and flowpaths are provided in
Appendix A with further details provided in Section 3.
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
2.3. CLIMATE
The Bureau of Meteorology (BOM) provides average annual rainfall data for the Eumundi-Crescent Road, Gauging
Station 040157. Based on this data, the average annual rainfall is 1,677 mm. Rainfall has a distinctly seasonal pattern,
with the majority of fall occurring between December and May. The average annual rainfall records are illustrated in
Figure 3.
Figure 3 –Average Annual Rainfall for Eumundi Crescent Road
2.4. MASTERPLAN
A masterplan has been prepared by ATC Williams for the Noosa landfill. Works are detailed for Years 1-5 and Years 6-10
in Figures 4 and 5.
Figure 4 – Masterplan Years 1-5 (Source: ATC Williams)
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
Figure 5 – Masterplan Years 6-10 (Source: ATC Williams)
Works for Years 1 to 5 include:
+ Ongoing Cell 2.2 operations
+ Cell 1.1 Expansion
+ Southern Clean Water Drain
+ SW5 HES basin
+ Cell 1.1 Batter Capping Works
+ Construction of Cell 3.2 & 3.3 (detailed as Cell 2.3 in Figure 4)
+ Construction of Cell 3.4 (detailed as Cell 2.4 in Figure 4)
+ Filling of Redevelopment Area for Green waste and Concrete Crushing
This report has been prepared for the works to be undertaken in Years 1 to 5. Although works to be undertaken between
Years 6 to 10 have been investigated in determination of control measures, it is recommended a revision to this document
be undertaken prior to these works.
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN
3 EXISTING STORMWATER MANAGEMENT
Based on discussion with site personnel, the site currently operates in the following manner:
1. Southern Catchment (SW5) – minimal disturbance and no sediment control prior to release (operating as a
stable catchment)
2. Cell 2.2 (active cell) – Captured in-situ and directed to Leachate system
3. Northern Catchment:
a. Portion directed to HES basin
b. Portion directed to Bio Basin (Green Waste)
c. Portion directed off-site as clean water
For further details relating to the existing drainage refer to Figure 6 and Appendix A.
Figure 6 – Existing Drainage Regime
3.1. RECOMMENDATIONS FOR CURRENT STORMWATER MANAGEMENT
The HES basin was designed in 2010 by Opus for a catchment size of 3.6 hectares. The current catchment that is estimated
to be draining to the basin is 3.9 hectares being within 10% of the design catchment. It is recommended that monitoring
is undertaken on the basin to ensure adequate performance with the current catchment draining to the basin.
Two assumptions have been made in relation to the catchment draining to the HES basin:
1. A pipe from Cell 1.1 is blocked to limit inflows to the HES basin. This was a recommendation from the 2013 O2
Report to be implemented once the catchment was stabilised (it is currently grassed). Some drainage
augmentation may be required to ensure the drain can flow to the desired clean water culvert. Refer to
Appendix A, Drawing Concept-09 for details
2. Stabilise the portion of the Existing landfill Cell 1.1/2.1 currently grading to the HES basin and divert the flows to
SW4 once stable. Refer to Appendix A, Drawing Concept-01 for catchment details and Concept-09 and
Concept-10 for flow paths. This will reduce the catchment to HES basin below the design catchment.
In addition to augmenting drainage, any catchments that are outside of those being directed to the HES basin or bio-
basin should be operating on a capture or erosion control (stabilisation) strategy. It is also recommended that a frog flap
be investigated for the outlet of the pipe from the HES basin due to flood levels.
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4 PROPOSED STORMWATER MANAGEMENT
This Operational Stormwater Management Plan has been prepared to detail proposed control measures and drainage
staging for future masterplanned works on site. For the purpose of this report, the works have been divided into two
main catchments:
+ Southern Catchment – Proposed Clean water drain and HES basin at the revised SW5 location
+ Northern Catchment – SW4 and SW2 with the proposed HES basin and drainage augmentation
4.1. SOUTHERN CATCHMENT (SW5)
Works occurring in the southern catchment include:
+ Ongoing Cell 2.2 operations
+ Cell 1.1 Expansion
+ Southern Clean Water Drain
+ SW5 HES basin
+ Construction of Cell 3.2 & 3.3
Detailed design has been undertaken for the Clean Water Drain and HES basin, along with Staging Plans, a Design Report
and a Concept Erosion and Sediment Control Plan for staging of construction works. Refer to Appendix B for the Design
Report which includes details on the staging plans, HES basin sizing and clean water drain sizing, and Appendix C for
the Concept Erosion and Sediment Control Plan for construction works stormwater management.
4.2. NORTHERN CATCHMENT (SW2 & SW4)
Works occurring in the northern catchment include:
+ Cell 1.1 Batter Capping Works
+ Construction of Cell 3.4
+ Filling of Redevelopment Area for Green waste and Concrete Crushing
Proposed stormwater management strategies for the Cell 1.1 Batter Capping Works are provided in Appendix C in the
Concept Erosion and Sediment Control Plan. Due to the lack of space on the northern capping works, use of the HES
basin would be the preferred management approach, however, this would exceed the design catchment unless the Cell
1.1/2.1 catchment currently grading to the HES basin can be stabilised and diverted prior to works (refer to Section 3.1).
Multiple options exist in regards to augmentation of the existing HES basin in conjunction with filling of the
redevelopment area and construction of Cell 3.4. These options are provided below based on discussions with NSC and
provided in Appendix A:
1. Widen Existing HES basin.
The current HES basin outlet is well below flood levels (provided by NSC) in the adjoining drainage channel creating
inflows to the HES basin outlet and limiting discharge from the outlet pipe. This is exacerbated due to a high point in
the downstream drainage channel.
Figure 7 – Existing HES Basin Outlet and Flood Levels
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Due to the constraints around the flood levels and outlets, it is not recommended to augment the existing basin w hich
has a piped outlet and spillway below the Q2 flood level.
A concept of this approach is provided in Appendix A, Drawing Concept-06 for the ultimate catchment. The approach
would also require filling of the northern portion of the pad to grade back to the basin inflow.
2. Construct New HES Basin
Based on discussions with NSC, the preferred location for a new basin would be in the north-western corner of the pad,
being where the proposed filling is to occur. Two options for the direction of the basin are provided in Appendix A,
Drawing Concept-06 and Concept-07.
There are two main options in regards to levels for the HES basin:
+ Design the piped outlet and spillway above nominated flood level (e.g. Q10)
+ Design the spillway only above nominated flood level (e.g. Q10), with the piped outlet below flood levels and to
include a frog flap to prevent backflows
Based on Figure 8, the ideal outlet location is along the northern boundary to prevent choked flows in the drainage
channel and existing high point to the west. An outlet along the northern boundary could be approximately RL 11.75.
The flood levels in this vicinity are approximately RL 12.50 (Q10).
Early discussions indicated the preference to locate the basin on the north-eastern corner of the pad. As the outlet
location here is approximately 2m higher than the proposed outlet, this location would require an additional 2m of fill
on the pad to achieve an outlet from the basin. As the pad level is governed by the outlet level and not the Minimum
Floor Levels, it is recommended that the lowest achievable outlet location be adopted to reduce fill requirements. Due
to the sensitivity of the outlet level, additional detailed survey is recommended along the northern boundary in the outlet
location.
Figure 8 – Northern Outflows (Proposed HES Basin)
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R2015: NOOSA LANDFILL - STORMWATER MANAGEMENT PLAN Figure 9 – Proposed HES Basin Outlet and Flood Levels With a Q10 flood level of RL 12.50, the emergency spillway would be required to be as a minimum RL 12.50. To achieve fall in the outlet channel to the low levels on the northern boundary, the piped outlet would be required to be above approximately RL 12.1. The outlet pipe could be set at a minimum of RL 12.1 to minimise fill required on the pad. A frog flap would be required to be installed on the outlet to limit backflows during flood events, however, the basin would still be operational during these events with outflows able to occur over the spillway (above the flood event) with settling occurring in the basin. If this does not occur another 0.5m of fill will be required across the entire pad. Based on a basin settling depth of 1.2m and piped outflow of RL 12.1, the emergency spillway would be approximately 13.3, with an inflow at approximately RL 13.9 to allow for fall through the basin and inlet channel. Pad levels would be required to be above RL 14.0 to ensure fall to the basin. Where drains are used instead of bunds to direct flow to the basin (recommended to avoid ponding on pads), additional fill would be required to achieve fall and freeboard within drainage channels. Details on the SW2 HES basin sizing are provided in Appendix D. 4.2.1. MANAGEMENT OF NUTRIENTS FROM GREEN WASTE AREA The current arrangement on site is to utilise a bio-retention basin to treat runoff from the Green Waste Area. To avoid construction of a bio-retention basin and a HES basin, the use of a floating wetland could be trialled in the end of the HES basin. Sunshine Coast Council are currently trialling this at their facilities and should be contacted prior to proceeding to design. Figure 10 – Floating Wetland installed at SCC landfill 4.2.2. DETAILED DESIGN Detailed design of the proposed HES basin and drainage will be required in consultation with NSC once pad layout and levels have been determined. This options provided for the SW2 augmentation in this report are concept only to provide guidance around potential options. Environment. Engineering. Education. PAGE 12
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5 SITE INSPECTION AND MONITORING
Site inspections and monitoring is to be undertaken as detailed below.
SMPs should be considered live documents that in some instances will require review and updating as site conditions
change, or if the adopted measures fail to achieve the required treatment standard.
When a site inspection detects a notable failure in the adopted drainage or other ESC measures, the source of this failure
must be reported, investigated and appropriate amendments made.
Best practice site management requires all ESC measures to be inspected at the following frequencies and include the
following checks as a minimum:
Daily site inspections (during rainfall)
+ All drainage, erosion and sediment control measures
+ Occurrences of excessive sediment deposition (whether on-site or off-site)
+ All site discharge points (including dewatering activities as appropriate)
Weekly site inspections (even if work is not occurring on-site)
+ All drainage, erosion and sediment control measures
+ Occurrences of excessive sediment deposition (whether on-site or off-site)
+ Occurrences of litter or sediment placed, deposited, or washed from the site, including deposition by vehicular
movements
+ Oil, fuel and chemical storage facilities
Following runoff producing rainfall (within 18 hours of rainfall event)
+ All drainage, erosion and sediment control measures
+ Occurrences of excessive sediment deposition (whether on-site or off-site)
+ Occurrences of litter or sediment placed, deposited, or washed from the site, including deposition by vehicular
movements
Environment. Engineering. Education. PAGE 13
Page 16
R0386A: NAMBOUR LANDFILL - STORMWATER MANAGEMENT PLAN 6 REFERENCES DES, 2021. Stormwater Guideline: Environmentally Relevant Activities, Brisbane: Department of Environment and Heritage. IECA, 2008. Best Practice Erosion and Sediment Control. Picton, NSW: International Erosion Control Association (Australasia). IPWEAQ, 2016. Queensland Urban Drainage Manual (Fourth Edition), Brisbane: Institute of Public Works Engineering Australasia, Queensland Division. O2, 2013. Noosa Landfill - Operational Phase Stormwater Management Plan, Sunshine Coast: O2. Environment. Engineering. Education. PAGE 14
Page 17
R0386A: NAMBOUR LANDFILL - STORMWATER MANAGEMENT PLAN APPENDIX A STORMWATER STAGING AND OPTIONS PLANS Environment. Engineering. Education. PAGE 15
Page 18
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT BOUNDARY
1 CATCHMENT LABEL
SW2 OUTLET
SW4 OUTLET FLOW DIRECTION
BIO FLOWPATH
PROPERTY BOUNDARY
OFFICE
POND SW4
SW4 BYPASS -
STABLE
CLEAN -
HES
INTERNAL
BASIN
SW5 OUTLET
CELL 2.2 TO
CLEAN - LEACHATE
EXTERNAL
SW5
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 80 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:4000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 CONCEPT STORMWATER STAGING
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) OVERALL CATCHMENT PLAN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-01 E
Page 19
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
BATTER FROM EXISTING CELL ACTIVE AREA
LIKELY TO ENTER CELL 2.2
AREA TO BE STABILISED
CELL 2.2 DIRECTED TO LEACHATE UNTIL AREAS CAN
GRADE OUT (LIKELY CROSS-OVER WITH EXPANSION
AS SHOWN IN STAGE 2)
REGRADING OF AREA OR TEMPORARY
BUNDS / DRAINS REQUIRED TO GRADE
RUNOFF TO SEIDMENT BASIN INLET
FINAL / TEMPORARY DRAINAGE PROPOSED SEDIMENT BASIN
PORTION OF CATCHMENT NOT LIKELY TO ENTER REQUIRED TO GRADE RUNOFF TO BASIN
CLEAN WATER DRAIN . AREA HAS BEEN ASSUMED TO
ENTER DRAIN TO BE CONSERVATIVE FOR DRAIN SIZING
STOCKPILE COULD REMAIN AND CLEAN WATER
DRAIN CONTINUED ONCE STOCKPILE IS CATCHMENT TO BASIN - 3.2 HA
REMOVED. CATCHMENTS TO CLEAN WATER
DRAIN AND BASIN ARE ASSUMED WORST CASE
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 3.6 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 1
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-02 E
Page 20
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
BATTER FROM EXISTING CELL ACTIVE AREA
LIKELY TO ENTER CELL 2.2
AREA TO BE STABILISED
CELL 1.1 AND 2.2 TO BE EXPANDED. UNTIL WASTE IS
ABOVE SURROUNDING GROUND LEVEL, CAPTURED
RUNOFF TO BE PUMPED TO LEACHATE TANKS
REGRADING OF AREA OR TEMPORARY
BUNDS / DRAINS REQUIRED TO GRADE
RUNOFF TO SEIDMENT BASIN INLET
FINAL / TEMPORARY DRAINAGE PROPOSED SEDIMENT BASIN
PORTION OF CATCHMENT NOT LIKELY TO ENTER REQUIRED TO GRADE RUNOFF TO BASIN
CLEAN WATER DRAIN . AREA HAS BEEN ASSUMED TO
ENTER DRAIN TO BE CONSERVATIVE FOR DRAIN SIZING
STOCKPILE COULD REMAIN AND CLEAN WATER
DRAIN CONTINUED ONCE STOCKPILE IS CATCHMENT TO BASIN - 4.0 HA
REMOVED. CATCHMENTS TO CLEAN WATER
DRAIN AND BASIN ARE ASSUMED WORST CASE
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 3.6 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 2
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-03 E
Page 21
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CELL 3.2 & 3.3 BEING CONSTRUCTED AND SELF
CONTAINED (NO FLOW TO BASIN). CAPTURED
RUNOFF CAN BE PUMPED TO HES BASIN CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
ACTIVE AREA
AREA TO BE STABILISED
CELL 1.1 AND 2.2 TO
CAPACITY
BE EXPANDED.
REACHEDUNTIL WASTE IS
AND BEING
ABOVE SURROUNDING
CAPPED ANDGROUND
LANDSCAPED
LEVEL, CAPTURED
RUNOFF TO BE PUMPED TO LEACHATE TANKS
FINAL / TEMPORARY DRAINAGE PROPOSED SEDIMENT BASIN
PORTION OF CATCHMENT NOT LIKELY TO ENTER REQUIRED TO GRADE RUNOFF TO BASIN
CLEAN WATER DRAIN . AREA HAS BEEN ASSUMED TO
ENTER DRAIN TO BE CONSERVATIVE FOR DRAIN SIZING
STOCKPILE COULD REMAIN AND CLEAN WATER
DRAIN CONTINUED ONCE STOCKPILE IS CATCHMENT TO BASIN - 3.2 HA
REMOVED. CATCHMENTS TO CLEAN WATER
DRAIN AND BASIN ARE ASSUMED WORST CASE
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 3.6 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 3
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-04 E
Page 22
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CELL 3.2 & 3.3 SPLIT INTO QUADRANTS.
ONCE FLOW CAN BE CONVEYED TO BASIN
A MAXIMUM OF TWO QUADRANTS CLEAN WATER DRAIN
CONVEYED TO BASIN. OTHER QUADRANTS
CAPTURED OR DIRECTED TO CLEAN DIRTY WATER DRAIN
WATER DRAINS - TO BE DETERMINED
THROUGH CELL 3.2 & 3.3 DETAILED DESIGN
PROPERTY BOUNDARY
ACTIVE AREA
AREA TO BE STABILISED
CELL 1.1 AND 2.2 EXPANSION AREAS STABILISED
AND DIRECTED TO CLEAN WATER DRAIN
NEW DIRTY WATER DRAIN
TO CONVEY ACTIVE RUNOFF
TO SEDIMENT BASIN
TIEING IN CLEAN WATER DRAIN BATTER WITH
CELL TRACK OR GRADING TRACK DRAIN INTO
CLEAN WATER DRAIN WILL BE REQUIRED PROPOSED SEDIMENT BASIN
CATCHMENT TO BASIN - 4.5 HA
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 6.2 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 4
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-05 E
Page 23
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
EXISTING BIO BASIN
CATCHMENT TO BIO
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
FLOOD LEVELS PROVIDED BY NSC:
Q1 - 12.76 DIRTY WATER DRAIN
EXISTING HES BASIN CATCHMENT TO BIO - 1.8 HA
Q2 - 12.79
Q10 - 12.92 PROPERTY BOUNDARY
Q100 - 13.07
Q100 CC - 13.16 ACTIVE AREA
AREA TO BE STABILISED
PIPED OUTLET RL 11.30
EMERGENCY SPILLWAY RL 12.20 INFLOW RL 12.50
CATCHMENT TO BASIN - 3.9 HA
BASIN DEISGNED FOR 3.6 HA
ACCESS TRACK DRAINAGE
AND SMALL SECTION OF CELL
2.2 DIRECTED TO HES BASIN
PIPE TO BE BLOCKED AS PER O2 SMP
AREA TO BE STABILISED
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) CURRENT APPROACH
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-09 E
Page 24
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO BIO
CATCHMENT - 5.6 HA 1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
REDIRECT DRAIN TO DIRTY WATER DRAIN
DISCHARGE AT SW4 ONCE
CATCHMENT IS STABILISED PROPERTY BOUNDARY
REFER TO D12A,D12B,D12C & D13 ACTIVE AREA
FOR PAD WATER QUALITY OPTIONS
AREA TO BE STABILISED
CELL 2.4 NOT UNDER
CONSTRUCTION
PIPE TO BE BLOCKED AS PER O2 SMP
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 1
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-10 E
Page 25
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO BIO
CATCHMENT - 7.3 HA 1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
NEW CLEAN WATER DRAIN - IF NOT PIPED, CELL 2.4 DRAINAGE
REFER TO D12A,D12B,D12C & D13 WOULD NEED TO BE CONVEYED OVER OPEN DRAIN. ESTIMATED ACTIVE AREA
FOR PAD WATER QUALITY OPTIONS AT 900mm RCP TO CONVEY 10 YEAR ARI UNDER PAD
AREA TO BE STABILISED
CELL 2.4 ACTIVE - NOTE: UINTIL CELL IS ABOVE GROUND IT WILL
NOT GRADE TO RRC PAD AND WILL BE MANAGED VIA LEACHATE
OR CLEAN WATER PUMP OUT IF CELL IS SEGMENTED
PIPE TO BE BLOCKED AS PER O2 SMP
BLOCK CULVERT AND DIRECR
RUNOFF ALONG ACCESS -
AUGMENT AS REQUIRED
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 2
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-11 E
Page 26
OPTION A - WIDEN EXISTING HES BASIN AND KEEP THE SAME LEVELS
LEGEND
NOTE - THIS OPTION IS NOT RECOMMENDED DUE TO OUTLET ISSUES DUE TO
HIGH POINT IN DOWNSTREAM DRAINAGE CHANNEL AND FLOOD LEVELS EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
HES BASIN
X BIO BASIN
RL 11.5
FLOW DIRECTION
X EXISTING FLOWPATH
RL 12.5
X CLEAN WATER DRAIN
RL 13.5
DIRTY WATER DRAIN
PROPERTY BOUNDARY
TO GET THIS PORTION OF THE PAD BACK TO
THE INLET, LEVELS WOULD BE ABOVE RL 13.0 ACTIVE AREA
(ABOVE MINIMUM FLOOR LEVEL)
AREA TO BE STABILISED
X
FLOOD LEVELS PROVIDED BY NSC: X EXISTING SURFACE LEVEL
BASED ON MODELLING, EXISTING BASIN WOULD NOT BE RL 13.5
Q1 - 12.76 REQUIRED TO BE WIDENED SIGNIFICANTLY. HOWEVER, RL 13.5
Q2 - 12.79 THIS ASSUMES A WELL PERFORMING BASIN WITHOUT
Q10 - 12.92 OUTLET CONSTRAINTS DUE TO HIGH TAILWATER
Q100 - 13.07
Q100 CC - 13.16
X X
RL 13.5 RL 14.0
EXISTING
INFLOW RL 12.50
X
RL 14.0
X
RL 15.0
PIPED OUTLET RL 11.30
EMERGENCY SPILLWAY RL 12.20
EXISTING DECANT OUTLETS AND SPILLWAY ARE X
EXISTING DRAINAGE COULD
WELL BELOW Q2 FLOOD LEVELS. RL 14.0
X REMAIN OR BE MODIFIED
RL 15.0
X
RL 14.0
X
RL 14.0
X
RL 17.0
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 20 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:1000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) PAD OPTION - WIDEN EXISTING BASIN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-12A E
Page 27
OPTION B - NEW NORTH-SOUTH HES BASIN FLOOD LEVELS PROVIDED BY NSC:
Q1 - 12.43 LEGEND
Q2 - 12.44
Q10 - 12.51 EXISTING CONTOURS (0.5m)
Q100 - 12.59
Q100 CC - 12.64 CATCHMENT TO BASIN
PIPED OUTLET - RL 12.1 (REQUIRES FROG FLAP AS
BELOW Q2 FLOOD LEVEL). DOWNSTREAM END OF HES BASIN
PIPE RL 12.0 AND THEN DRAINAGE CHANNEL TO
CONVEY FLOWS OFF SITE. PIPED OUTLET COULD
X BIO BASIN
BE RAISED ABOVE Q2 FLOOD EVENT, HOWEVER,
RL 11.5 THIS WOULD REQUIRE ADDITIONAL PAD FILL. BASIN
WILL STILL OPERATE WITH DECANTS BLOCKED - FLOW DIRECTION
REFER TO SMP REPORT
X EXISTING FLOWPATH
SPILLWAY RL 13.3 (WELL ABOVE FLOOD LEVELS)
RL 12.5
BASIN BASED ON A SETTLING DEPTH OF 1.2m. WIDER, X CLEAN WATER DRAIN
LONGER BASIN COULD BE UTILISED (DASHED LINE) AND
WOULD REDUCE SETTLING DEPTH TO 0.9m AND INFLOW RL 13.5
DIRTY WATER DRAIN
AND PAD LEVEL FILL BY 0.3m
PROPERTY BOUNDARY
TO GET THIS PORTION OF THE PAD BACK TO THE
INLET, LEVELS WOULD BE ABOVE RL 14.0 (ABOVE ACTIVE AREA
MINIMUM FLOOR LEVEL), AND LIKELY CLOSER TO RL
15.0 TO HAVE A DRAIN GRADING FLOW BACK
AREA TO BE STABILISED
X
X EXISTING SURFACE LEVEL
RL 13.5
RL 13.5
X X
RL 13.5 RL 14.0
INFLOW RL 13.90
X
RL 14.0
X
RL 15.0
DRAINAGE AND PAD LEVELS TO BE X
MODIFIED TO ACHIEVE INFLOW LEVEL OF
RL 14.0
X NEW BASIN. WHERE DRAINS ARE USED,
PAD LEVEL LIKELY TO BE RL 15 OR HIGHER
RL 15.0
X
RL 14.0
X
RL 14.0
X
RL 17.0
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 20 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:1000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) PAD OPTION - NORTH-SOUTH BASIN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-12B E
Page 28
OPTION C - NEW EAST-WEST HES BASIN PIPED OUTLET - RL 12.1 (REQUIRES FROG FLAP AS
BELOW Q2 FLOOD LEVEL). DOWNSTREAM END OF LEGEND
PIPE RL 12.0 AND THEN DRAINAGE CHANNEL TO
CONVEY FLOWS OFF SITE. PIPED OUTLET COULD EXISTING CONTOURS (0.5m)
BE RAISED ABOVE Q2 FLOOD EVENT, HOWEVER,
THIS WOULD REQUIRE ADDITIONAL PAD FILL. BASIN CATCHMENT TO BASIN
FLOOD LEVELS PROVIDED BY NSC:
WILL STILL OPERATE WITH DECANTS BLOCKED -
Q1 - 12.43
REFER TO SMP REPORT
Q2 - 12.44
HES BASIN
Q10 - 12.51
SPILLWAY RL 13.3 (WELL ABOVE FLOOD LEVELS)
Q100 - 12.59
Q100 CC - 12.64 BIO BASIN
X
RL 11.5
FLOW DIRECTION
X EXISTING FLOWPATH
RL 12.5
X CLEAN WATER DRAIN
RL 13.5
DIRTY WATER DRAIN
INFLOW RL 13.90
BASIN BASED ON A SETTLING DEPTH OF 1.2m. WIDER,
LONGER BASIN COULD BE UTILISED (DASHED LINE) AND PROPERTY BOUNDARY
WOULD REDUCE SETTLING DEPTH TO 0.9m AND INFLOW
AND PAD LEVEL FILL BY 0.3m ACTIVE AREA
AREA TO BE STABILISED
X
X EXISTING SURFACE LEVEL
TO GET THIS PORTION OF THE PAD BACK TO THE RL 13.5
INLET, LEVELS WOULD BE ABOVE RL 14.0 (ABOVE RL 13.5
MINIMUM FLOOR LEVEL), AND LIKELY CLOSER TO RL
15.0 TO HAVE A DRAIN GRADING FLOW BACK
X X
RL 13.5 RL 14.0
X
RL 14.0
X
RL 15.0
DRAINAGE AND PAD LEVELS TO BE X
MODIFIED TO ACHIEVE INFLOW LEVEL OF
RL 14.0
X NEW BASIN. WHERE DRAINS ARE USED,
PAD LEVEL LIKELY TO BE RL 15 OR HIGHER
RL 15.0
X
RL 14.0
X
RL 14.0
X
RL 17.0
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 20 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:1000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) PAD OPTION - EAST-WEST BASIN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-12C E
Page 29
HIGH - EFFICIENCY SEDIMENT BASIN BIO-RETENTION BASIN
1. ALLOW APPROXIMATELY 5-6% OF CATCHMENT AREA DEPENDING ON DEPTH 1. ALLOW APPROXIMATELY 2-3.5% OF CATCHMENT AREA INCLUDING FOREBAY
2. BASINS REQUIRE APPROXIMATELY 2m OF FALL FROM INLET TO OUTLET TO ACT AS A TYPE A BASIN - SELF DRAINING 2. CAN BE USED FOR GREEN WASTE AREA
3. IF NO OUTLET CAN BE ACHIEVED, A FULL BASIN COULD BE ADOPTED (TYPE B BASIN), HOWEVER WOULD NEED TO NEGOTIATE WITH DES 3. COULD BE ADOPTED FOR ENTIRE RRC IF PAD IS SEALED AND SEDIMENT IS NOT THE KEY CONTAMINANT OF CONCERN
FOREBAY LENGTH MAIN CELL LENGTH
DECANT SKIMMER
LEVEL SPREADER
MAXIMUM FROM TOP OF
DRAIN INVERT MIN. CREST MIN. 0.2m
WATER WATER COLUMN
0.2m ABOVE LEVEL ABOVE SPILLWAY SPILLWAY CREST
CREST LEVEL
SPREADER 0.3m (MIN)
HIGH FLOW
FLOC SETTLING DEPTH (DF) (OVER
SETTLING ZONE DEPTH (DS) SPILLWAY)
FREE WATER ZONE (DFF) DEPTH (DT)
SEDIMENT STORAGE DEPTH (DSS)
DECANT
STRUCTURE LOW FLOW
OUTLET
TYPE A SEDIMENT BASIN TYPICAL SECTION (nts)
AUTOMATED
DOSING SYSTEM LEVEL SPREADER
TO BE FULL WIDTH
OF BASIN
SPILLWAY AND
CHUTE TO BE
LINED AS
SPECIFIED
FOREBAY WIDTH
MAIN CELL WIDTH
INLET DRAIN
(OR PIPE) FOREBAY LENGTH MAIN CELL LENGTH
FLOW DIRECTION
FLOATING WETLAND
DECANT SKIMMER
ARMS ON TOP OF
1. COULD BE IMPLEMENTED IN HES BASIN TO MANAGE NUTRIENT LOADS FROM GREEN WASTE AREA (NO NEED TO
WATER COLUMN DECANT LOW FLOW SEPARATE AREA FOR BIO BASIN)
STRUCTURE OUTLET
2. CURRENTLY BEING TRIALLED AT CALOUNDRA LANDFILL
TYPE A SEDIMENT BASIN PLAN VIEW (nts)
FOREBAY LENGTH MAIN CELL LENGTH
LEVEL SPREADER
CREST MIN. 0.2m MAXIMUM
DRAIN INVERT MIN. WATER
0.2m ABOVE LEVEL ABOVE SPILLWAY
CREST LEVEL
SPREADER 0.3m (MIN) SPILLWAY CREST
FLOC SETTLING DEPTH (DF)
SETTLING ZONE DEPTH (DS)
DEPTH (DT)
SEDIMENT STORAGE DEPTH (DSS)
TYPE B SEDIMENT BASIN TYPICAL SECTION (nts)
AUTOMATED
DOSING SYSTEM LEVEL SPREADER
TO BE FULL WIDTH
OF BASIN
SPILLWAY AND
CHUTE TO BE LINED
AS SPECIFIED
FOREBAY WIDTH
MAIN CELL WIDTH
INLET DRAIN (OR
PIPE)
FOREBAY LENGTH MAIN CELL LENGTH
FLOW DIRECTION
TYPE B SEDIMENT BASIN PLAN VIEW (nts)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21
COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - NORTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
E REVISION TO NORTH OPTIONS KR 10/12/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) PAD OPTIONS - ADDITIONAL INFORMATION
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-13 E
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R0386A: NAMBOUR LANDFILL - STORMWATER MANAGEMENT PLAN APPENDIX B SW5 DESIGN REPORT Environment. Engineering. Education. PAGE 16
Page 31
DESIGN REPORT & MAINTENANCE
AND INSPECTION PLAN
NOOSA LANDFILL – CLEAN WATER DRAIN &
HIGH-EFFICIENCY SEDIMENT BASIN (SW5)
CLIENT: NOOSA SHIRE COUNCIL
DOCUMENT NUMBER: R1767
VERSION: IFC
DATE: 05/10/21
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
TABLE OF CONTENTS
1 INTRODUCTION 1
2 CATCHMENT AND STAGING 1
3 DRAINAGE DESIGN 1
3.1. DIVERSION DRAIN TO BASIN 1
3.2. INLET DRAIN FOR DOSING 1
3.3. LEVEL SPREADER WEIR 1
3.4. DECANT STRUCTURE 1
3.5. EMERGENCY SPILLWAY 1
3.6. CLEAN WATER DIVERSION DRAIN 2
3.6.1. MANNINGS ROUGHNESS SENSITIVITY ANALAYSIS 2
4 BASIN VOLUME AND SIZE 2
4.1. EA REQUIREMENT 2
4.2. ASSESSMENT APPROACH 2
4.3. HISTORIC RAINFALL PERIOD 2
4.4. CATCHMENT 2
4.5. CATCHMENT LOSSES 3
4.5.1. 10 YEAR 24 HOUR TRADITIONAL BASIN 3
4.5.2. TYPE A HES BASIN 3
4.6. BASIN OPERATION APPROACH 3
4.6.1. 10 YEAR 24 HOUR TRADITIONAL BASIN 3
4.6.2. TYPE A HES BASIN 3
4.7. RESULTS 3
5 HYDROLOGIC & HYDRAULIC MODELLING 3
5.1. RAINFALL 4
5.2. PEAK FLOW RATE 4
5.4. PEAK FLOW DEPTHS 6
6 OPERATION & MAINTENANCE 7
6.1. DOSING SYSTEM 7
6.2. MONITORING SYSTEM 7
6.3. SEDIMENT BASIN 7
6.3.1. FOREBAY 7
6.3.2. MAIN CELL 8
6.4. DESIGN EVENT & COMPLIANCE 8
APPENDIX A – CATCHMENTS & STAGING 9
APPENDIX B – BASIN CALCULATIONS 10
Environment. Engineering. Education PAGE ii
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN 1 INTRODUCTION This design report applies to proposed construction of the Southern Clean Water Drain and the High-Efficiency Sediment Basin located at outlet SW5. This design report has been provided to detail catchments, staging and operational requirements for the proposed sediment basin and clean water drain. 2 CATCHMENT AND STAGING The maximum catchment assumed to drain to the sediment basin is 4.5 hectares. This will occur as Cell 3.2 and 3.3 is formed and can grade to the basin. It should be noted that to minimise the size of the basin, Cell 3.2 and 3.3 is required to be split into quadrants to ensure the maximum catchment to the basin is not exceeded. This will allow a maximum of half of Cell 3.2 and 3.3 to be graded to the basin. The maximum catchment grading to the clean water drain is 6.2 hectares. This will occur once Cell 1.1 and Cell 2.2 are capped and stabilised. The maximum catchment defined does not include the additional 4.5 hectares grading to the sediment basin which will overtop into the final portion of the clean water drain. For assessment purposes, this additional catchment has been included in the assessment of the downstream portion of the clean water drain. Details on Catchments and Staging is provided in Appendix A. 3 DRAINAGE DESIGN 3.1. DIVERSION DRAIN TO BASIN The diversion drain to the basin has been sized for the 1 in 10 year ARI critical storm event in accordance with the Guideline - Stormwater and environmentally relevant activities (DES, 2019). The Environmental Authority (EPPR01855314) also specifies that the design event for temporary drainage works to convey waters to the sediment basin and around disturbance areas is a 1 in 10 year ARI event plus 150mm freeboard for > 24 months disturbance. To cater for the 4.5 hectare catchment and flat grade, a 3m wide turf lined drain with a minimum depth of 700mm including freeboard is required. Refer to Section 5 for hydraulic modelling undertaken. 3.2. INLET DRAIN FOR DOSING To improve accuracy of flow depth measurement, the drain width at the dosing point has been reduced to 0.7m by increasing the longitudinal grade from 0.7% to 3% and providing a concrete lining. The inlet drain has also been sized for the 1 in 10 year ARI critical storm event in accordance with the Guideline - Stormwater and environmentally relevant activities (DES, 2019). Refer to Section 5 for hydraulic modelling undertaken. 3.3. LEVEL SPREADER WEIR The level spreader is the weir in between the forebay and main cell. The level spreader has been sized for the 100 year ARI critical storm event which is in excess of the 50 year ARI required in accordance with the Guideline - Stormwater and environmentally relevant activities (DES, 2019). The level spreader has a width of 16 m and is concrete lined with a full width concrete chute. The maximum water depth across the weir in a 100 year ARI is 190 mm. Refer to Section 5 for hydraulic modelling and Appendix B for calculations undertaken. 3.4. DECANT STRUCTURE The decant structure has been designed in accordance with Appendix B - Sediment Basins (IECA, 2018). In accordance with Table 5 of the document a maximum decant flow rate of 9L/s/ha has been adopted. To achieve a total of 40.5L/s through the decant arms, a total of 13 decant arms would be required utilising the standard of 200 holes with a diameter of 10mm. To reduce the number of arms to a pracital number, 17mm diameter holes are to be utilsied to increase the flow rate to approximately 13L/s per arm, allowing the use of 3 arms and a single manhole structure. 3.5. EMERGENCY SPILLWAY The emergency spillway from the main cell has been sized for the 100 year ARI critical storm event which is in excess of the 50 year ARI required in accordance with the Guideline - Stormwater and environmentally relevant activities (DES, Environment. Engineering. Education. PAGE 1
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
2019). The spillway has a width of 15 m and is concrete lined with a rock chute and dissipater. The maximum water depth
across the weir in a 100 year ARI is 170 mm.
Refer to Section 5 for hydraulic modelling and Appendix B for calculations undertaken.
3.6. CLEAN WATER DIVERSION DRAIN
The clean water diversion drain has been sized for the 1 in 10 year ARI critical storm event in accordance with the Guideline
- Stormwater and environmentally relevant activities (DES, 2019).
To cater for the maximum 6.2 hectare catchment and flat grade, a 3m wide turf lined drain with a minimum depth of
500mm to 700mm including freeboard is required. Refer to Section 5 for hydraulic modelling undertaken.
3.6.1. MANNINGS ROUGHNESS SENSITIVITY ANALAYSIS
An analysis of the sensitivity of flood depths with the clean water drain was undertaken based on a fully turfed drain vs
a turf lined base with vegetated batters. A Manning’s roughness of 0.15 was adopted as a worst case scenario for the
planted batters.
The sensitivity analysis indicate a flood depth increase ranging from 30mm to 80mm in the drain, however, all flows will
be contained within the drain indicating no concern in regards to planting batters from a flow conveyance position.
4 BASIN VOLUME AND SIZE
4.1. EA REQUIREMENT
The Environmental Authority (EPPR01855314) specifies that site erosion protection measures and sediment control
measure must be implemented to have the hydraulic effectiveness to treat stormwater for 90% of the annual runoff for
each stormwater catchment.
4.2. ASSESSMENT APPROACH
An assessment of a Type A High-Efficiency Sediment basin was undertaken utilising the MUSIC (Model for Urban
Stormwater Improvement Conceptualisation) software as a water balance model to determine the percentage of annual
runoff discharged from the decant structure rather than over the emergency spillway. In accordance with IECA (2018),
Type A basins are sized to allow the design event runoff to discharge (treated) from the decant structure with any runoff
overtopping the emergency spillway to be considered over-design. The MUSIC analysis was undertaken for three Type
A sediment basin design events (and corresponding basin sizes):
+ 1 year ARI, 24 hour (short-term design event in accordance with IECA (2018))
+ 2 year ARI, 24 hour
+ 5 year ARI, 24 hour (long-term design event in accordance with IECA (2018))
In addition, a comparison of the effectiveness of a 10 year 24 hour traditional sediment basin was undertaken using a
water balance model to determine the percentage of annual runoff that would be captured and treated by the basin.
This assessment is not required to determine the size of the Type A sediment basin, however, provides some additional
justification for achieving a 90% annual runoff treatment target.
4.3. HISTORIC RAINFALL PERIOD
The models utilised 10 years of historic rainfall from the Cooroy Composite Station (Station ID 40059) for the period
between 1/1/1973 – 31/12/1983. This period is considered representative of historic rainfall and is in accordance with the
Water By Design MUSIC Modelling Guidelines. A 6 minute timestep was utilised in the HES basin assessment, where a
daily rainfall total was utilised from the Station data for the traditional basin assessment.
4.4. CATCHMENT
A 1 hectare catchment was assessed. A range of catchment sizes were also assessed for the HES basin model as a
sensitivity analysis. It was found that that catchment size did not significantly affect the annual runoff treatment
performance.
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
4.5. CATCHMENT LOSSES
4.5.1. 10 YEAR 24 HOUR TRADITIONAL BASIN
A sensitivity analysis of a range of Initial and Ongoing losses was undertaken for the water balance model. As the losses
associated with rainfall also affected the basin size (traditional basin size is calculated based on catchment size, design
rainfall depth and rainfall loss) it was found that the losses adopted had minimal effect on the percentage of annual
runoff treated with performance ranging from 83.4 – 85.5%.
4.5.2. TYPE A HES BASIN
To ensure the HES basin model catchment runoff was consistent with the traditional basin model, the fraction impervious
in the source node was modified to ensure the total annual runoff was equivalent to the traditional basin model. This
was undertaken for a range of losses utilised in the traditional basin model for comparison purposes.
4.6. BASIN OPERATION APPROACH
4.6.1. 10 YEAR 24 HOUR TRADITIONAL BASIN
For the purpose of the model, it was assumed that only runoff that was captured and had 5 consecutive days of no
runoff (i.e. minimal rainfall) would achieve treatment and release and could be considered treated. If further rainfall
occurred within the 5 succeeding days, then it was assumed the basin had not been dewatered and the basin would
continue to fill or overtop if that capacity had been reached. Any runoff that overtopped the spillway was considered to
be untreated.
4.6.2. TYPE A HES BASIN
For the purpose of the model, an outlet pipe was sized in the MUSIC model based on the proposed decant outlet rate
in accordance with IECA (2018). All runoff discharging from the decant structure was considered treated with any runoff
overtopping the spillway to be considered untreated. This is in accordance with the design approach detailed in IECA
(2018).
4.7. RESULTS
The results below show the percentage of annual runoff treated for a range of basin types sized in accordance with IECA
(2018).
Table 1 – Performance of 10 year 24 hour basin vs HES basins with various design events
Percentage of
Annual Runoff
Treated
1 in 10 year 24 hour traditional basin 85.2%
1 in 1 year 24 hour Type A basin (HES) 90.3%
1 in 2 year 24 hour Type A basin (HES) 93.0%
1 in 5 year 24 hour Type A basin (HES) 96.3%
Based on the results provided, a 1 in 1 year ARI Type A basin will exceed the performance of a 10 year 24 hour traditional
sediment basin and also achieve the 90% requirement of annual runoff treatment specified in the Environmental
Authority.
5 HYDROLOGIC & HYDRAULIC MODELLING
Hydrologic and hydraulic modelling has been carried out using the XP-Storm software. Drain sections have been
modelled as per the design plans for the 10 % AEP and 1 % AEP events. The layout of the model is illustrated as Figure
1, showing the clean and dirty water drains.
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
Figure 1 – XP Model for Drainage Assessment
5.1. RAINFALL
Modelling was undertaken for 10 % and 1 % Annual Exceedance Probability (AEP) storm events for durations between 15
minutes and 3 hours. Intensity Frequency Duration (IFD) data for the hydrologic modelling was obtained from the Bureau
of Meteorology website, and has been developed in accordance with Australian Rainfall and Runoff (ARR) 2016. The IFD
data is summarised in Table 2.
Table 2 – Intensity Frequency Duration Data
DURATION (mins) 10 % AEP (MM/HR) 1 % AEP (MM/HR)
15 152.0 217.0
20 133.0 191.0
25 119.0 172.0
30 108.0 158.0
45 87.1 129.0
60 74.2 112.0
90 59.0 90.7
120 50.1 78.1
180 39.8 63.3
5.2. PEAK FLOW RATE
A range of design storm durations was assessed to ensure the critical duration event was taken into consideration. The
Guideline - Stormwater and environmentally relevant activities (EHP, 2014) requires that high erosion hazard sites
implement the following design and management measures:
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
+ All concentrated stormwater flows (including ‘clean’ stormwater and ‘dirty’ stormwater) should have
concentrated flow paths, such as drainage lines, diversion drains, channels and batter chutes (where applicable)
which have been designed, constructed, effectively armoured and maintained to convey the runoff from events
up to and including the average recurrence interval (ARI) of 1 in 10 year critical duration ARI storm event without
causing water contamination, sheet, rill or gully erosion, sedimentation, or damage to structures or property.
The Environmental Authority (EPPR01855314) also specifies that the design event for temporary drainage works to convey
waters to the sediment basin and around disturbance areas is a 1 in 10 year ARI event plus 150mm freeboard for > 24
months disturbance. Design has been undertaken to ensure this criteria is satisfied, with an additional assessment of the
1 % AEP (100 year ARI) undertaken as a sensitivity analysis on flow depth within the drains.
The peak flow rates for locations within the drains are detailed below in Table 3.
Table 3 – Peak Flow Rates & Velocities
PEAK FLOW (M3/S) – UPSTREAM OF NODE MAX. VELOCITY (M/S) – UPSTREAM OF NODE
LOCATION
10% AEP 1% AEP 10% AEP 1% AEP
CH0 - - - -
CH100 1.443 2.470 0.766 0.906
CH132 1.442 2.465 1.245 1.464
CH282 1.418 2.412 0.762 0.885
CH430 1.955 3.316 0.831 0.976
CH523 1.950 3.306 1.394 1.635
CH558 3.404 5.739 1.187 1.394
CH623 3.499 5.902 1.797 2.101
CH668 3.498 5.900 1.435 1.687
CH716 3.472 5.858 0.796 0.940
HES DWD - - - -
Doser Inlet 1.530 1.915 0.774 0.910
Forebay 1.530 1.916 3.856 4.448
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
5.4. PEAK FLOW DEPTHS
An assessment of depth within the clean water and dirty water drains is detailed below in Table 4.
Table 4 – Depth Assessment
10 % AEP 1 % AEP
INVERT LEVEL
NODE PEAK WATER LEVEL DEPTH PEAK WATER LEVEL DEPTH
(m AHD)
(m AHD) (M) (m AHD) (M)
CH0 25.263 25.683 0.420 25.812 0.549
CH100 24.563 24.830 0.267 24.920 0.357
CH132 23.636 24.028 0.392 24.154 0.518
CH282 22.631 23.127 0.496 23.273 0.642
CH430 21.550 21.843 0.293 21.939 0.389
CH523 18.100 18.664 0.564 18.823 0.723
CH558 17.749 18.172 0.423 18.299 0.550
CH623 15.350 15.705 0.355 15.825 0.475
CH668 14.210 14.747 0.537 14.920 0.710
CH716 14.000 14.565 0.565 14.733 0.733
HES DWD 21.600 22.115 0.515 22.257 0.657
Doser Inlet 21.000 21.304 0.304 21.396 0.396
Forebay 20.700 21.000 0.300 21.100 0.400
Calculations for rock sizing, weir sizing and rock dissipaters are provided in Appendix B.
Environment. Engineering. Education. PAGE 6
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
6 OPERATION & MAINTENANCE
The SW5 High Efficiency Sediment (HES) basin is to have both dosing and monitoring systems installed.
6.1. DOSING SYSTEM
The dosing system will read real time flow rates and dose the applicable volume of the Coagulant/Flocculant into the
inflow stream as it passes the dosing point. The data collected is to be sent to a cloud-based data platform for storage
and future interrogation.
Maintenance and operation of the dosing system is to be detailed by the dosing system supplier.
6.2. MONITORING SYSTEM
The monitoring system will read real time water quality parameters such as:
• Turbidity,
• pH,
• Electrical Conductivity, and
• Dissolved Oxygen.
The monitoring system is to also control a power actuated valve on the outlet to the basin. When the water quality
readings are outside the site’s environmental approval conditions the valve will close, stopping any potential outflows
from occurring.
All data collected from the monitoring and shut-off valve is to be sent to a cloud-based data platform for storage and
future interrogation.
Maintenance and operation of the monitoring system is to be detailed by the monitoring system supplier.
Figure 2 – Typical Dosing and Monitoring Setup (Source: Turbid)
6.3. SEDIMENT BASIN
6.3.1. FOREBAY
The Forebay will require clean out periodically. Access into the ramp can be gained from the defined access track.
Dewatering into the main cell is recommended if the forebay is to be drained to remove sediment. A sump has been
located in the north western corner of the forebay to assist in desilting. Desilting is recommended to be undertaken once
accumulation is causing large resuspension with inflows. This may be at approximately 50% full.
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
Desilting is not a requirement from a compliance point, with the forebay acting as a mixing mechanism rather than a
storage or treatment volume.
6.3.2. MAIN CELL
The main cell has a defined sediment storage volume between RL 18.30 and RL 18.60. A sump has been located in the
northern corner of the main cell to assist in desilting. Desilting is recommended to be undertaken once accumulation is
50% of the sediment storage zone. A marker post is to be installed to monitor the depth of sediment accumulation.
6.3.3. EQUIPMENT FOR CLEAN-OUT
The concrete specification has been designed based on access via a rubber wheel/tracked Posi-track. The concrete ramps
and floor of the basin are not to be accessed by larger equipment which may exceed the design loadings.
6.4. DESIGN EVENT & COMPLIANCE
The sediment basin has been sized as a Type A sediment basin with a design event of a 1 year ARI 24 hour storm event
equating to 136mm in 24 hours. If this event is exceeded, it is expected that outflows may exceed the EA requirements.
For events under the nominated design event, outflows are to be in accordance with the EA requirements. Where the
sediment basin is not adhering to the water quality requirements, interrogation of dosing and monitoring data should
be undertaken or advice sought from a specialist.
Table 5 – WT2 EA water quality requirements for controlled releases
PARAMETER RELEASE LIMIT COMMENTS
pH 6.5 -9 .0 Real-Time included on Monitoring Station
Specific Conductance < 1500 uS/cm Real-Time included on Monitoring Station
Dissolved Oxygen > 6 mg/L Real-Time included on Monitoring Station
Total & Dissolved Aluminium N/A Sampling to be manual by NSC
Suspended Solids < 50 Cannot measure in the field. Correlation with
Turbidity to be gained by > 5 sampling events
during initial releases from basin.
Turbidity Correlation Correlation to be undertaken if not currently
used
Environment. Engineering. Education. PAGE 8
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R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN APPENDIX A – CATCHMENTS & STAGING Environment. Engineering. Education. PAGE 9
Page 42
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT BOUNDARY
1 CATCHMENT LABEL
FLOW DIRECTION
BIO FLOWPATH
PROPERTY BOUNDARY
OFFICE
POND SW4
SW4 BYPASS -
STABLE
CLEAN -
HES
INTERNAL
BASIN
CELL 2.2 TO
CLEAN - LEACHATE
EXTERNAL
SW5
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 80 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:4000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 CONCEPT STORMWATER STAGING
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 31/03/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) OVERALL CATCHMENT PLAN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-01 D
Page 43
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
BATTER FROM EXISTING CELL ACTIVE AREA
LIKELY TO ENTER CELL 2.2
AREA TO BE STABILISED
CELL 2.2 DIRECTED TO LEACHATE UNTIL AREAS CAN
GRADE OUT (LIKELY CROSS-OVER WITH EXPANSION
AS SHOWN IN STAGE 2)
REGRADING OF AREA OR TEMPORARY
BUNDS / DRAINS REQUIRED TO GRADE
RUNOFF TO SEIDMENT BASIN INLET
FINAL / TEMPORARY DRAINAGE PROPOSED SEDIMENT BASIN
PORTION OF CATCHMENT NOT LIKELY TO ENTER REQUIRED TO GRADE RUNOFF TO BASIN
CLEAN WATER DRAIN . AREA HAS BEEN ASSUMED TO
ENTER DRAIN TO BE CONSERVATIVE FOR DRAIN SIZING
STOCKPILE COULD REMAIN AND CLEAN WATER
DRAIN CONTINUED ONCE STOCKPILE IS CATCHMENT TO BASIN - 3.2 HA
REMOVED. CATCHMENTS TO CLEAN WATER
DRAIN AND BASIN ARE ASSUMED WORST CASE
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 3.6 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 31/03/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 1
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-02 D
Page 44
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
BATTER FROM EXISTING CELL ACTIVE AREA
LIKELY TO ENTER CELL 2.2
AREA TO BE STABILISED
CELL 1.1 AND 2.2 TO BE EXPANDED. UNTIL WASTE IS
ABOVE SURROUNDING GROUND LEVEL, CAPTURED
RUNOFF TO BE PUMPED TO LEACHATE TANKS
REGRADING OF AREA OR TEMPORARY
BUNDS / DRAINS REQUIRED TO GRADE
RUNOFF TO SEIDMENT BASIN INLET
FINAL / TEMPORARY DRAINAGE PROPOSED SEDIMENT BASIN
PORTION OF CATCHMENT NOT LIKELY TO ENTER REQUIRED TO GRADE RUNOFF TO BASIN
CLEAN WATER DRAIN . AREA HAS BEEN ASSUMED TO
ENTER DRAIN TO BE CONSERVATIVE FOR DRAIN SIZING
STOCKPILE COULD REMAIN AND CLEAN WATER
DRAIN CONTINUED ONCE STOCKPILE IS CATCHMENT TO BASIN - 4.0 HA
REMOVED. CATCHMENTS TO CLEAN WATER
DRAIN AND BASIN ARE ASSUMED WORST CASE
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 3.6 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 31/03/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 2
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-03 D
Page 45
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CELL 3.2 & 3.3 BEING CONSTRUCTED AND SELF
CONTAINED (NO FLOW TO BASIN). CAPTURED
RUNOFF CAN BE PUMPED TO HES BASIN CLEAN WATER DRAIN
DIRTY WATER DRAIN
PROPERTY BOUNDARY
ACTIVE AREA
AREA TO BE STABILISED
CELL 1.1 AND 2.2 TO
CAPACITY
BE EXPANDED.
REACHEDUNTIL WASTE IS
AND BEING
ABOVE SURROUNDING
CAPPED ANDGROUND
LANDSCAPED
LEVEL, CAPTURED
RUNOFF TO BE PUMPED TO LEACHATE TANKS
FINAL / TEMPORARY DRAINAGE PROPOSED SEDIMENT BASIN
PORTION OF CATCHMENT NOT LIKELY TO ENTER REQUIRED TO GRADE RUNOFF TO BASIN
CLEAN WATER DRAIN . AREA HAS BEEN ASSUMED TO
ENTER DRAIN TO BE CONSERVATIVE FOR DRAIN SIZING
STOCKPILE COULD REMAIN AND CLEAN WATER
DRAIN CONTINUED ONCE STOCKPILE IS CATCHMENT TO BASIN - 3.2 HA
REMOVED. CATCHMENTS TO CLEAN WATER
DRAIN AND BASIN ARE ASSUMED WORST CASE
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 3.6 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 31/03/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 3
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-04 D
Page 46
LEGEND
EXISTING CONTOURS (0.5m)
CATCHMENT TO BASIN
CATCHMENT TO CWD
1 CATCHMENT LABEL
FLOW DIRECTION
EXISTING FLOWPATH
CELL 3.2 & 3.3 SPLIT INTO QUADRANTS.
ONCE FLOW CAN BE CONVEYED TO BASIN
A MAXIMUM OF TWO QUADRANTS CLEAN WATER DRAIN
CONVEYED TO BASIN. OTHER QUADRANTS
CAPTURED OR DIRECTED TO CLEAN DIRTY WATER DRAIN
WATER DRAINS - TO BE DETERMINED
THROUGH CELL 3.2 & 3.3 DETAILED DESIGN
PROPERTY BOUNDARY
ACTIVE AREA
AREA TO BE STABILISED
CELL 1.1 AND 2.2 EXPANSION AREAS STABILISED
AND DIRECTED TO CLEAN WATER DRAIN
NEW DIRTY WATER DRAIN
TO CONVEY ACTIVE RUNOFF
TO SEDIMENT BASIN
TIEING IN CLEAN WATER DRAIN BATTER WITH
CELL TRACK OR GRADING TRACK DRAIN INTO
CLEAN WATER DRAIN WILL BE REQUIRED PROPOSED SEDIMENT BASIN
CATCHMENT TO BASIN - 4.5 HA
INLET TO BASIN RL 21.1
CLEAN WATER DRAIN
CATCHMENT TO DRAIN - 6.2 HA
(EXCLUDING OVERTOP FROM BASIN)
CLIENT PROJECT
D CELL NUMBER REVISION KR 20/09/21 0 40 COPYRIGHT C NOOSA SHIRE COUNCIL NOOSA LANDFILL STORMWATER MANAGEMENT PLAN
C FINAL DESIGN REPORT KR 03/06/21 TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B NEW ATC DESIGN KR 12/04/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 31/03/21 STORMWATER MANAGEMENT - SOUTH
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 31/03/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) STAGE 4
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CONCEPT-05 D
Page 47
R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN APPENDIX B – BASIN CALCULATIONS Environment. Engineering. Education. PAGE 10
Page 48
R1767: NOOSA LANDFILL: CLEAN WATER DRAIN AND HES BASIN (SW5) – DESIGN REPORT & MAINTENANCE AND INSPECTION PLAN
1 YEAR ARI 24 HOUR TYPE A SEDIMENT BASIN
NUMBER
JAR TEST
SETTLING DECANT DECANT OF
CATCH DESIGN SETTLE QA QA MINIMUM MINIMUM ACTUAL EMPTY FULL
BATTERS L:W DEPTH IX yr, 24 hr GOVERN DFW MANUAL NUMBER HOLE DECANTS
BASIN ID AREA EVENT AFTER 15 OPTIMUM SELECTED Vs As VS SCOUR SCOUR
(1 IN X) RATIO DS (mm/hr) FACTOR (m) DFW (m) OF DIAMETER REQUIRED
(HA) (ARI) MINUTES (L/s/ha) (L/s/ha) (m3) (m2) (m3) CHECK CHECK
(m) HOLES (mm) FOR QA
(mm)
SELECTED
SW5 4.5 2 3 1.20 1 5.68 100 17 9 1662 486 VOLUME 1662 0.20 0.50 200 17 3.1 OK OK
LEVEL SPREADER
WEIR
MIN. HEIGHT
CATCH AREA TIME OF CONC FLOW - Q SIDE SLOPE 1 U/S WATER TOP WIDTH
BASIN ID ARI CARI IARI BASE WIDTH FREEBOARD (m) SPILLWAY TO
(HA) (MINS) (m3/s) (1 in x) LEVEL (m) (m)
TOB (m)
LEVEL SPREADER Q10 4.5 10 0.7 15 152 1.33 16 2 0.13 0.3 0.43 17.73
LEVEL SPREADER Q100 4.5 100 0.84 15 217 2.28 16 2 0.19 0.3 0.49 17.96
EMERGENCY SPILLWAY
WEIR CHUTE DISSIPATER
SIDE MIN. MEAN
TIME U/S DEPTH DEPTH
CATCH FLOW SLOPE HEIGHT TOP LONG. ROCK MANNING DESIGN ROCK WIDTH
OF BASE WATER FREEBOARD OF WITH WIDTH LENGTH
BASIN ID AREA ARI CARI IARI -Q 1 SPILLWAY WIDTH SLOPE SIZE - D50 ROUGH VEL SIZE - 1
CONC WIDTH LEVEL (m) FLOW F/BOARD 2 (m) (m)
(HA) (m3/s) (1 in TO TOB (m) (m/m) (mm) COEFF (m/s) D50 (m)
(MINS) (m) (m) (m)
x) (m) (mm)
SPILLWAY Q100 4.5 100 0.7 15 217 1.90 15 2 0.17 0.3 0.47 16.90 0.25 93 0.087 1.24 0.10 0.40 100 17.2 17.4 2.1
Environment. Engineering. Education. PAGE 11
Page 49
R0386A: NAMBOUR LANDFILL - STORMWATER MANAGEMENT PLAN APPENDIX C CONCEPT EROSION AND SEDIMENT CONTROL PLAN Environment. Engineering. Education. PAGE 17
Page 50
CONCEPT EROSION AND SEDIMENT CONTROL PLAN
/ STORMWATER MANAGEMENT
NOOSA LANDFILL EXPANSION
CLIENT: NOOSA SHIRE COUNCIL
DOCUMENT NUMBER: R1890
VERSION: IFC
DATE: 05/10/2021
Page 51
R1890: NOOSA LANDFILL EXPANSION – CONCEPT ESCP
1 INTRODUCTION
Topo was engaged by Noosa Shire Council (NSC) to prepare a Concept Erosion and Sediment Control Plan (CESCP) /
stormwater management approach for the Noosa Landfill Expansion project during construction of the proposed High-
Efficiency Sediment Basin, Clean Water Drain and Existing Cell Capping.
1.1. OBJECTIVES & SCOPE
The objective of this CESCP is to provide an Erosion and Sediment Control Strategy that is in accordance with
Environmental Authority (Ref: EPPR01855314).
This plan describes a stormwater management strategy that could be utilised to comply with the requirements of the
Environmental Authority. For the bulk of the proposed works, runoff can be captured within work zones, therefore
limiting discharge to controlled releases through pumping. Due to the sensitivity of the receiving environment and the
requirements of the Environmental Authority, it is recommended that a capture approach be adopted where practical.
Where this cannot occur, management of stormwater and erosion and sediment controls measures are to be in
accordance with the requirements of the Environmental Authority.
This document is provided as a high-level strategy only. The Principal Contractor is to prepare a detailed Erosion and
Sediment Control Plan for the proposed works by a Certified Professional in Erosion and Sediment Control (CPESC). This
document is to include detailed calculations for drainage and sediment controls as well as proposed staging.
2 DETAILED ESCP AND ESC/STORMWATER MANAGEMENT
2.1. LEGAL REQUIREMENTS
Stormwater runoff has the potential to cause water contamination and/or environmental harm and is regulated under
the Environmental Protection (EP) Act 1994. Some of the key legal requirements relevant to the operation of the waste
transfer station and management of the closed landfill include:
+ Where stormwater conditions appear on an environmental authority, it is an offence under s.430 of the EP Act,
to not comply with the conditions of approval. This includes anyone operating under the environmental
authority e.g. contractors, consultants etc.
+ Causing serious or material environmental harm is an offence under s.437 and s.438 of the EP Act respectively.
+ It is an offence to cause an environmental nuisance under s.440. Environmental nuisance is unreasonable
interference with an environmental value. It may also include an unhealthy, offensive or unsightly condition
because of contamination.
+ Under s.440ZG it is an offence to unlawfully deposit a prescribed water contaminant to waters. The most
common prescribed contaminants resulting from poor stormwater management of ERA operations are:
+ clay, gravel, sediment, stones and similar organic or inorganic matter
+ building and construction materials
+ building, construction and demolition waste
+ putrescible waste
+ Under s.319 an obligation is placed upon all persons in Queensland who are carrying out activities which may
cause environmental harm to comply with the ‘general environmental duty’. This requires that all reasonable
and practicable measures must be adopted to prevent and minimise environmental harm. Although not being
able to demonstrate compliance against the general environmental duty is not an offence, demonstrating that
all reasonable and practicable measures have been adopted is a defence for offences such as water
contamination (EHP, 2014).
2.2. GUIDELINES
The Principal Contractor is to prepare a detailed Erosion and Sediment Control Plan for the proposed works by a Certified
Professional in Erosion and Sediment Control (CPESC) that is in accordance with:
+ Best Practice Erosion and Sediment Control (IECA, 2008)
Although the ESCP is to be prepared in accordance with the above document, the drainage and sediment control
standards are to be in accordance with the Environmental Authority as detailed in Section 2.3. The intent of the ESCP is
to ensure management of runoff from works areas is compliant with the Environmental Authority and water quality
release criteria.
Environment. Engineering. Education. PAGE ii
Page 52
R1890: NOOSA LANDFILL EXPANSION – CONCEPT ESCP 2.3. KEY LICENSE CONDITIONS AND WATER QUALITY OBJECTIVES A list of key licence conditions from the Environmental Authority relating to erosion and sediment control is provided below. The fundamental condition relating to erosion and sediment control is condition WT1 with a defined sediment basin and drainage standard for temporary works Figure 1 – Condition WT1 (Sediment and Drainage Control Standard) Treated Runoff is to achieve the requirements of Condition WT2. Where runoff is to be discharged from site, the superintendent is to be notified prior to release. Figure 2 – Condition WT2 (Water Quality Release Criteria) Environment. Engineering. Education. PAGE 3
Page 53
R1890: NOOSA LANDFILL EXPANSION – CONCEPT ESCP
3 CONCEPTUAL STORMWATER STRATEGY
A conceptual strategy for each works areas is provided in Appendix A. The strategy adopted by the Principal Contractor
for the works may differ due to the proposed staging or construction methodology.
A summary of the conceptual strategy is provided below for each section of works:
1. Cell 1.1 & 2.2 Expansion – The bulk of works are in cut, so as works progress the areas will be self contained.
During early works prior to significant excavation, the outer ends of the works are to be bunded to contain
runoff.
2. Perimeter Road – The perimeter road is predominantly in fill. As fill is raised with the perimeter road, runoff can
be directed into the excavation for the Cell 1.1 & 2.2 Expansion or into the excavation with the Clean Water Drain.
Any batters that are outside of the holding areas should be progressively stabilised as fill is raised through the
use of permanent measures or temporary measures such as soil binder.
3. Clean Water Drain – The drain is predominantly in cut. As works progress the downstream end can be left high
so all runoff is contained within the excavation. It is not likely to be practical to divert external runoff away from
the drain, so all runoff will be required to be captured within the work zone. As works progress to the
downstream end of works where runoff cannot be contained, works are to be staged and rapidly stabilised
prior to rainfall through the use of temporary or permanent measures.
4. Sediment Basin – The sediment basin is all in cut. As stripping occurs a perimeter bund can be placed around
works prior to excavation occurring to self contain all runoff within the works area.
5. Capping Works (Southern Batter) – Dams are located along the toe of the southern batter. It is unclear if these
dams have sufficient capacity to contain the required design event as a temporary sediment basin, however, if
suitable could be utilised.
6. Capping Works (Western Batter) – The western batter can be directed to the existing High-Efficiency Sediment
basin in consultation with the superintendent. Temporary drainage will be required to ensure runoff is directed
to the basin.
3.1. USE OF EXISTING DAMS / HES BASIN
The use of existing dams on site is to be requested and approved by NSC prior to works. The Principal Contractor and
NSC will agree on the following:
+ Final state of dams – will clean out and treatment be required prior to project completion
+ Agreed pump and dewatering locations to and from the holding dams
+ Approved coagulant / flocculant product
The use of the existing HES basin on site is also to be requested and approved by NSC prior to capping works. The
Principal Contractor and NSC will agree on the following:
+ Final state of basin – will clean out and treatment be required prior to project completion
+ Agreed pump and dewatering locations to the HES basin
+ Agreed catchment and/or flow rates to the basin
+ Cost of operation / coagulant
Environment. Engineering. Education. PAGE 4
Page 54
R1890: NOOSA LANDFILL EXPANSION – CONCEPT ESCP APPENDIX A CONCEPT EROSION AND SEDIMENT CONTROL DRAWINGS Environment. Engineering. Education. PAGE 5
Page 55
LEGEND
EXISTING CONTOURS (0.5m)
WORKS AREA
SW2 RELEASE POINT SW4 RELEASE POINT FLOW DIRECTION
EXISTING FLOWPATH
EXISTING HES BASIN
EXISTING FLOWPATH TO DAMS
CELL 1.1 CAPPING -
WESTERN BATTER
EXISTING SW5 RELEASE POINT
FUTURE SW5 RELEASE POINT
EXISTING SITE DAMS CELL 1.1 CAPPING -
SOUTHERN BATTER
EXISTING SITE DAM
CELL 1.1 & 2.2 EXPANSION
PERIMETER ROAD
SEDIMENT BASIN
CLEAN WATER DRAIN
CLIENT PROJECT
0 80 NOOSA SHIRE COUNCIL
COPYRIGHT C NOOSA LANDFILL EXPANSION
TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B REVISION FOLLOWING NSC COMMENTS KR 16/09/21
SCALE 1:4000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 14/09/21 CONCEPT EROSION AND SEDIMENT CONTROL
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 14/09/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) WORKS AREAS
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CESCP-01 B
Page 56
LEGEND
EXISTING CONTOURS (0.5m)
WORKS AREA
FLOW DIRECTION
EXISTING FLOWPATH
EXISTING FLOWPATH TO DAMS
BUND
CAPTURED WATER IN WORKED ZONE TO BE TREATED AND
DEWATERED IN-SITU OR AS AGREED WITH SUPERINTENDENT
DURING STRIPPING, FORM LARGE BUND ACROSS CURRENT GULLY
TO ENSURE WORKS AREA IS ENCAPSULATED UNTIL ADDITIONAL
FILL IS PLACED TO FORM BUNDED ZONE (CAN INCORPORATE INTO
PERIMETER ROAD FILL IF UNDERTAKEN AT THE SAME TIME)
DURING STRIPPING, FORM LARGE BUND ACROSS CURRENT
GULLY TO ENSURE WORKS AREA IS ENCAPSULATED UNTIL
EXCAVATION OCCURS TO FORM SELF CAPTURED ZONE
CLIENT PROJECT
0 20 NOOSA SHIRE COUNCIL
COPYRIGHT C NOOSA LANDFILL EXPANSION
TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B REVISION FOLLOWING NSC COMMENTS KR 16/09/21
SCALE 1:1000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 14/09/21 CONCEPT EROSION AND SEDIMENT CONTROL
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 14/09/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) CELL 1.1 & 2.2 EXPANSION
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CESCP-02 B
Page 57
LEGEND
EXISTING CONTOURS (0.5m)
WORKS AREA
FLOW DIRECTION
EXISTING FLOWPATH
EXISTING FLOWPATH TO DAMS
FILL BUND
SEDIMENT FENCE
GRADE FILL INTO EXISTING DRAIN - INSTALL EXISTING DAM COULD BE UTILISED FOR BATCH TREATMENT OF
SEDIMENT CONTROL OR INCORPORATE INTO CAPTURED WORK ZONES (RUNOFF PUMPED TO DAM). NSC IS TO
CAPPING WORKS SEDIMENT BASINS / CONTROLS BE NOTIFIED IF DAM IS TO BE UTILISED WITH AGREEMENT ON
POST CONSTRUCTION RECTIFICATION TO BE UNDERTAKEN
PLACE SEDIMENT FENCE AT TOE OF FILL. PROGRESSIVELY
STABILISE FILL AND GRADE FILL BACK TO SOUTH TO HOLD IN
CLEAN WATER DRAIN/ BEHIND PERIMETER ROAD FILL
PERIMETER ROAD ALL IN FILL. AS FILL IS RAISED - DIRECT
ALL RUNOFF INTO CELL EXPANSION WORKS TO BE
CAPTURED. SOUTHERN SIDE OF FILL TO BE FILL CAN BE DIRECTED TO CELL EXPANSION CAPTURE OR
PROGRESSIVELY STABILISED WITH SOIL BINDER AS RAISED TO CLEAN WATER DRAIN HOLDING AREA DEPENDING ON
WHICH WORKS ARE BEING UNDERTAKEN CONCURRENTLY
CLIENT PROJECT
0 40 NOOSA SHIRE COUNCIL
COPYRIGHT C NOOSA LANDFILL EXPANSION
TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B REVISION FOLLOWING NSC COMMENTS KR 16/09/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 14/09/21 CONCEPT EROSION AND SEDIMENT CONTROL
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 14/09/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) PERIMETER ROAD
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CESCP-03 B
Page 58
LEGEND
EXISTING CONTOURS (0.5m)
WORKS AREA
FLOW DIRECTION
EXISTING FLOWPATH
EXISTING FLOWPATH TO DAMS
BUND
EXISTING DAM COULD BE UTILISED FOR BATCH TREATMENT OF
CAPTURED WORK ZONES (RUNOFF PUMPED TO DAM). NSC IS TO
BE NOTIFIED IF DAM IS TO BE UTILISED WITH AGREEMENT ON
POST CONSTRUCTION RECTIFICATION TO BE UNDERTAKEN
AS WORKS PROGRESS TO NORTH WHERE BUNDING WILL
NOT CAPTURE RUNOFF, RAPIDLY UNDERTAKE WORKS AND
TURF PRIOR TO RAINFALL. IF TURF CANNOT BE PLACED,
APPLY TEMPORARY MATTING (JUTE) OR APPLY SOIL BINDER
PROVIDE BUND DURING EARLY WORKS AT
WESTERN END AS REQUIRED TO ENSURE
NO RUNOFF CAN LEAVE WORKS AREA
ENSURE END OF CURRENT WORKS IS BUNDED (CAN LEAVE
SECTION HIGH WITH ALL EXCAVATION UPSLOPE). THIS WILL ALLOW
ALL RUNOFF FROM CLEAN WATER DRAIN TO BE CAPTURED.
CAPTURED WATER IN WORKED ZONE TO BE TREATED AND
CONSTRUCT BUND IN GULLY IF PERIMETER DEWATERED IN-SITU OR AS AGREED WITH SUPERINTENDENT
ROAD IS NOT UNDERTAKEN CONCURRENTLY
ADDITIONAL BUNDS MAY BE REQUIRED IN
NOT PRACTICAL TO DIVERT UPSLOPE SECTIONS TO RETAIN ALL RUNOFF
EXTERNAL RUNOFF AROUND WORKS
CLIENT PROJECT
0 40 NOOSA SHIRE COUNCIL
COPYRIGHT C NOOSA LANDFILL EXPANSION
TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B REVISION FOLLOWING NSC COMMENTS KR 16/09/21
SCALE 1:2000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 14/09/21 CONCEPT EROSION AND SEDIMENT CONTROL
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 14/09/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) CLEAN WATER DRAIN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CESCP-04 B
Page 59
LEGEND
EXISTING CONTOURS (0.5m)
WORKS AREA
FLOW DIRECTION
EXISTING FLOWPATH
EXISTING FLOWPATH TO DAMS
FILL BUND
SEDIMENT FENCE
PLACE SEDIMENT FENCE AROUND TOE OF WORKS.
LOCATION WILL BE DEPENDENT ON CLEAN WATER
DRAIN BEING UNDERTAKEN CONCURRENTLY
ALL WORKS ARE IN CUT. TOPSOIL BUND CAN
BE PLACED AROUND WORK ZONE DURING
EALRY WORKS UNTIL AREA IS EXCAVATED
CLIENT PROJECT
0 20 NOOSA SHIRE COUNCIL
COPYRIGHT C NOOSA LANDFILL EXPANSION
TOPO GROUP PTY LTD
DRAWN DESIGNED DATE DRAWING TITLE
B REVISION FOLLOWING NSC COMMENTS KR 16/09/21
SCALE 1:1000 THIS DOCUMENT MAY NOT BE COPIED OR KR KR 14/09/21 CONCEPT EROSION AND SEDIMENT CONTROL
ISSUED FOR USE TRANSMITTED IN ANY FORM OR BY ANY
A ORIGINAL ISSUE KR 14/09/21 MEANS IN PART OR IN WHOLE WITHOUT
RPEQ / SIGNATURE (IF REQUIRED) SEDIMENT BASIN
NORTH
A3 THE WRITTEN CONSENT OF TOPO GROUP CPESC - 5395, RPEQ - 15954 PROJECT No DRAWING No REVISION
REVISION DESCRIPTION APPROVED BY DATE PTY LTD. 20-0211 CESCP-05 B
The text continues on page 60.