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ROCKY GULLY ROAD, COOMINYA QUARRY

STORMWATER MANAGEMENT PLAN

Prepared for: Zanows’ Concrete and Quarries Date: 16/05/2017

Reference: 2004.610.001

Coominya Quarry DRAFT Page i Stormwater Management Plan

Document Control

16/05/2017 This document is uncontrolled when printed.

2004.610.001 DRAFT GROUNDWORK p l u s

Project/ Report Details

Document Title: Stormwater Management Plan

Principal Author: Tom Manning

Client: Zanows’ Concrete and Quarries

Ref. No. 2004.610.001

Document Status

Issue Description Date Author Reviewer

1 Stormwater Management Plan 16/05/2017 T. Manning T. Smith

Distribution Record

Recipient Delivery method

Zanows’ Concrete and Quarries Electronic

Department of Environment and Heritage Protection Electronic

Groundwork Plus ABN: 13 609 422 791

Copyright © These materials or parts of them may not be reproduced in any form, by any method, for any purpose except with written permission from Groundwork Plus.

Queensland 6 Mayneview Street, Milton Qld 4064 PO Box 1779, Milton BC, Qld 4064

P: +61 7 3871 0411 F: +61 7 3367 3317

South Australia 2/1 First Street, Nuriootpa SA 5355 PO Box 854, Nuriootpa SA 5355

P: +61 8 8562 4158

E: [email protected]

Rocky Gully Road, Coominya Quarry DRAFT Page ii Stormwater Management Plan

Table of Contents



1. Introduction ......................................................................................................................................................... 3

1.1 Project Overview ........................................................................................................................................... 3 1.2 Site Details .................................................................................................................................................... 3 1.3 Scope of Works ............................................................................................................................................ 3 1.4 Site Survey and Topography ........................................................................................................................ 3

2. Stormwater Quality Treatment System Design ................................................................................................ 4

2.1 Design Criteria .............................................................................................................................................. 4 2.2 Erosion and Soil Management Controls ....................................................................................................... 4

2.2.1 Clean Water Diversion Design Calculations ............................................................................................. 4 2.2.2 Sediment Basin Design Calculations ........................................................................................................ 5 2.2.3 Sediment Basin Spillway Sizing Calculations ........................................................................................... 5

3. Operational Management Procedures ............................................................................................................... 7

3.1 Stockpiling of Materials ................................................................................................................................. 7 3.2 Bunding of Fuels and Chemicals .................................................................................................................. 8 3.3 Clean Water Diversion Drains/Bunds ........................................................................................................... 8 3.4 Sediment Basin Structures ........................................................................................................................... 8 3.5 Site Access ................................................................................................................................................... 8

4. Stormwater Management Plan Implementation ............................................................................................. 11

4.1 Monitoring Management Measures ............................................................................................................ 11 4.2 Auditing and Review ................................................................................................................................... 11 4.3 Reporting and Responsibility ...................................................................................................................... 11 4.4 Identification of Incident or Failure .............................................................................................................. 11 4.5 Corrective Action ........................................................................................................................................ 11

5. Conclusion ......................................................................................................................................................... 12

6. Reference List ................................................................................................................................................... 13

FIGURES Figure 1 Site Layout Map Drawing No. Z2004-004r1 Figure 2 Stormwater Management Layout Plan Drawing No. Z2004-007

Rocky Gully Road, Coominya Quarry DRAFT Page 3 Stormwater Management Plan



1. Introduction

1.1 Project Overview

This Stormwater Management Plan (SMP) has been prepared for Zanows’ Concrete and Quarries (Zanows) for a sand and gravel extraction operation proposed at Rock Gully Road, Coominya (the Site) identified as Lot 236 on SP260138, Lot 246 on CA31773, Lot 220 on SP250792, Lot 225 on CA31641 and Lot 226 on CA31641. The boundary of the Site, showing access to Rock Gully Road and the more detailed site layout plan have been included for reference (as Figure 1 - Site Layout Map). The ERAs will be carried out under a Development Approval (DA) for the activity, issued by Somerset Regional Council (Council), as well as an Environmental Authority (EA) issued by the Department of Environment and Heritage Protection (EHP). The Site is also located within a SEQ Water water supply catchment and is therefore subject to the water quality outcomes prescribed in the SEQ Water Development Guidelines (2012).

1.2 Site Details

Location: Rock Gully Road and Banffs Lane, Coominya, QLD, 4311

Access: Rock Gully Road

Real Property Description: Lot 236 on SP260138, Lot 246 on CA31773, Lot 220 on SP250792, Lot 225 on CA31641 and Lot 226 on CA31641

Local Authority: Somerset Regional Council

Assessing Authority: Department of Environment and Heritage Protection

Area: 322.641 Hectares

Tenure: Freehold

1.3 Scope of Works

The scope of this SMP includes the following work items undertaken by Groundwork Plus in order of engagement:

• Review SEQ Water Development Guidelines and address where necessary • Conduct a catchment delineation and hydrologic assessment • Undertake engineering designs for stormwater quality treatment system • Undertake a site based water balance modelling to ensure the proposed measure are in accordance

with EHP guidelines • Develop an operational plan for implementation and maintenance of stormwater quality treatment

system This SMP outlines the engineering design details and operational management procedures Zanows will adopt in order to integrate stormwater management and EA licence compliance into daily operations and site activity.

1.4 Site Survey and Topography

The Site occupies land that fronts Buaraba Creek, and is situated on ground with elevations between RL59.0 – RL90.0m AHD. A tributary of Buaraba Creek flows west to east directly through the centre of the Site. Refer to Figure 1 – Site Layout Map for details on existing site surface topography and features.




2. Stormwater Quality Treatment System Design

2.1 Design Criteria

The Erosion Control Association (IECA): Best Practice Erosion and Sediment Control (2008) (IECA) design guidelines were used to design an engineering solution to meet stormwater quality treatment appropriate for the Site operations.

2.2 Erosion and Soil Management Controls

The proposed quarry footprint is shown in Figure 2 – Stormwater Management Layout Plan. A model has been undertaken to assess the required stormwater management measures based on the proposed site layout against the design criteria set out in the Environment Protection Act (EPA) and SEQ Water Development Guidelines.

2.2.1 Clean Water Diversion Design Calculations

IECA requires that all clean water diversions must be designed to adequately convey flow from the peak 20 year ARI rainfall event. However, SEQ Water Development Guidelines states that all diversion drains are to be sized to cater for 50 year ARI event, therefore all diversion drains have been sized to convey a 50 year ARI event. Refer to Figure 2 – Stormwater Management Layout Plan for the location and extent of the proposed clean water diversion drains. As per IECA 2008, the average velocity and water depth for the existing clean water diversion drains are calculated based on the following modified Mannings equation:

Q = (1/n) x A x R2/3 x S1/2, where: Q = Channel flow rate (m3/s) n = Mannings roughness coefficient A = Cross sectional area of the flow (m2) R = Hydraulic Radius (m) S = Channel bed slope (m/m)

Table 1 – Clean Water Diversion Drain Sizing below details the required drain size to convey upstream flows around the overburden stockpile.

Table 1 – Clean Water Diversion Drain Sizing

Drain ID

Catchment Area (ha)

Q50 Peak Discharge (m3/s)

Base Width (m)

Batters (1v:Xh)

Minimum Depth (m)

Velocity (m/s)

Proposed Lining

CW1 3.20 1.32 1.0 3.0 0.50 1.32 Turf

CW2 25.71 6.98 7.0 3.0 0.75 1.62 Turf

CW3 42.27 6.87 9.0 3.0 1.00 1.03 Rock d50 = 200mm

The design criteria is for velocities to remain below 2.0m/s and depth x velocity product below 0.6m2/s, in order to ensure minimal erosion to the channel bed. As shown in Table 1 – Clean Water Diversion Drain Sizing, all diversion drains will experience acceptable velocities and will not require additional scour protection. It is proposed to provide turf over a 0.5m layer of well compacted material. Refer to Figure 2 – Stormwater Management Layout Plan for the location and extent of clean water diversion drains. Refer to Attachment 1 – Clean Water Diversion Calculations for calculations.




2.2.2 Sediment Basin Design Calculations

In order to meet the requirements of the Department of EHP Stormwater Guideline – Environmentally Relevant Activities (ERA) (EHP 2014), a sediment basin must be designed, constructed and operated to retain the runoff at the Site for events up to and including a 24 hour storm event with an ARI of 1 in 5 years. As outlined in the EHP Stormwater Guideline, the total upper settling storage requirements for sediment basins are calculated based on the following formula:

Vs = A *Cv * R (1 in 5; 24hr), where:

A = Catchment Area (m2) Cv = Coefficient of Discharge R = Rainfall depth (m) from 24 hour storm, and ARI of 1 in 5 years

In addition to the upper settling volume, a sediment storage zone is required to be accommodated based on 0.5 times the upper settling volume:

VSED = 0.5 * Vs Table 2 – Site Sediment Storage Requirements details the sediment basin storage requirements for the Site, based on a Coefficient of Discharge (Cv) of 0.70, and a Rainfall Depth (R) of 0.129m for an adopted average intensity of 5.38mm/h (Source: Bureau of Meteorology).

Table 2 – Site Sediment Storage Requirements

Basin ID Catchment area (ha)

Upper Settling Volume, Vs (m3)

Sediment Storage Volume, Vsed (m3)

Total Required Storage Volume, Vtot (m3)

Sediment Basin SB1 26.51 27.38 13.69 41.08

Sediment Basin SB2 11.48 11.27 5.63 16.90

Quarry Sump QS1 25.35 24.88 12.44 37.32

Quarry Sump QS2 86.87 85.25 42.63 127.88

Quarry Sump QS3 46.36 45.50 22.75 68.25

The details of the proposed layout for the sediment basins is included in Figure 2 –Stormwater Management Layout Plan. The Site is to be generally maintained in accordance with Figure 2 – Stormwater Management Layout Plan to ensure that adequate stormwater quality treatment measures are implemented on-site to prevent the release of contaminants from the Site. Refer to Attachment 2 – Sediment Basin Calculations (Proposed) for details of the sediment basin sizing calculations.

2.2.3 Sediment Basin Spillway Sizing Calculations

In order to adequately design the spillway of each sediment basin, hydrologic modelling was undertaken using DRAINS (a computer simulation program by Watercom). Details of the model set up and comprehensive hydrology results for the Site are included in Attachment 3 – Site Hydrology Calculations and Results. The Site was modelled to represent the hydraulic conditions of each sediment basin under certain design storm events. In accordance with IECA 2008, a 50 year ARI event was selected (peak discharge), in order to ensure each spillway has adequate design to convey overtopping, and remains structurally sound based on resistance to peak discharge and velocities of surface water. The proposed development layout shown in Figure 2 – Stormwater Management Layout Plan (Developed Scenario) was considered to ensure the spillways are suitable for the ultimate quarry development. The DRAINS schematic of the 50 year ARI (peak discharge) design storm is shown below in Diagram 1.




Diagram 1 – DRAINS Results (50 year ARI; Peak Discharge; Developed Scenario)

With reference to the DRAINS results shown in Diagram 1, the spillway of each sediment basin will need to be designed to convey the peak discharge shown in Table 3 – Sediment Basin Spillway Peak Discharge Estimations. The model assumes all Sediment Basins are already at capacity before the rainfall event, and all outlet pipes are blocked, representing the worst case scenario. As each quarry sump will be located at the bottom of each open cut pit, it is unlikely the sumps will overtop during the design storm event, as illustrated above in Diagram 1. Therefore the quarry sumps have been omitted from the spillway calculations.

Table 3 – Sediment Basin Spillway Peak Discharge Estimations

Spillway ID Sediment Basin ID Design ARI Peak Discharge (m3/s)

SW1 SB1 50 year

9.88

SW2 SB2 4.55

The spillway design specifications are outlined in Table 4 – Sediment Basin Spillway Design. The design criteria is for velocities to remain below 2.0m/s and depth x velocity product below 0.6m2/s, in order to ensure structural integrity. A rock lined spillway has been assumed, with appropriate and stable downstream conveyance.

Table 4 – Sediment Basin Spillway Design

Spillway ID

Base Width

(m)

Batters (1 in x)

Mannings (n)

Chute Slope (1 in x)

Flow Depth, d

(m)

Discharge Capacity

(Q)

Flow Velocity V (m/s)

Depth x Velocity (m2/s)

SW1 20.0 2.0 0.17 4.0 0.42 9.88 1.404 0.59

SW2 12.5 2.0 0.10 4.0 0.34 4.55 1.764 0.59

QS1

Legend 1.96 Peak Discharge (Overland Flow) 1.22 Peak Discharge (Catchment) 30.11 Peak Water Surface Level SB1 Sediment Basin ID C1 Catchment ID (Refer Figure 2) SW1 Spillway ID

C3 C1 C2

C4

SW1

SW2

SB1

QS2

SW3

Buaraba Creek

SB2 Buaraba Creek

Tributary

QS3

C5

C6 C7

C8

C9

C5

C10

C11

C13

C14 C12




3. Operational Management Procedures

This section outlines the stormwater management procedures to be adopted by Zanows to comply with EA licence conditions.

Stormwater Management Procedures Purpose

This Stormwater Management Plan has been prepared to manage potential environmental impacts that may result from the operation in relation to stormwater and surface water quality.

Risk Sources and Potential Impacts

Site operations that have the potential to impact on stormwater quality include:

• Sand Material Stockpiles. • Vegetation clearing (including grass). • Sediment Basins (if not maintained). • Topsoil stripping. • Construction and maintenance of carpark, roads and hardstands. • Spillage during handling of materials. • Use and storage of oils, greases, fuels and other chemicals.

Performance Targets

Water quality discharged from a controlled release point on the Site is to comply with the follow release criteria:

Water Quality Parameters

Parameter 100 percentile concentration limit pH 6.5 – 8.5

Total Suspended Soils (TSS) 50 mg/L

Responsibilities Zanows Quarry Manager will be primarily responsible for the implementation of this SMP

Strategies/mitigation measures:

Strategies/mitigation measures for the management of surface water runoff and erosion and sediment transport from the Site will be implemented in accordance the relevant approval conditions. Operational Procedures for mitigating identified risks are provided in the following measures.

3.1 Stockpiling of Materials

Ensure minimum buffer (5.0m) is maintained at all times from the site boundary to all stockpiled material The buffer distance is defined between the toe of the stockpile embankment and the surveyed Site boundary and must be minimum of 5.0m. Stockpiles of material must be:

• Adequately protected from wind, rain, concentrated surface flow and excessive upslope stormwater surface flows.

• Placated to direct drainage water to sediment basin systems in event of surface water runoff.

• Maintained in a moist state including by use of sprinklers to minimise the risk of movement by wind.

• Stored where practicable in a bay with the material not exceeding the height of the bay or cloth screen if stored for a period of greater than 5 days.




Stormwater Management Procedures

3.2 Bunding of Fuels and Chemicals

Install a secondary bund on all bulk chemical and fuel storage areas at all times. Clearly designate storage areas and do not deviate from assigned bunded areas for storage of chemicals and fuels unless a suitable secondary bund is provided.

3.3 Clean Water Diversion Drains/Bunds

Clean water diversion drains/bunds are to have greater than 80% vegetation coverage.

This coverage is required to be in-place at all times. Seeding of the exposed areas using approved native grass species. The grass species will be required to have the following characteristics (as per IECA 2008).

• Plants with a fibrous root system. • Plants that primarily grow horizontal rather than upright clumping plants. • Leguminous plants. • Non-invasive plants. • Avoid clumping or tussock forming grasses.

3.4 Sediment Basin Structures

Design, construct and maintain sediment basin system in accordance with Figure 2 – Stormwater Management Layout Plan.

• Details of sediment basin and engineering design are also included in Section 2 – Stormwater Quality Treatment System Design.

• Ensure sediment retention capacity is available at all times or within 5 days from receiving design rainfall event.

• Implement the inspection and maintenance program as detailed below in Table 5 - Monitoring and Maintenance of Stormwater Control Devices

3.5 Site Access

Site exit points must be appropriately managed to minimise the risk of sediment being tracked onto sealed, public roadways.

Street sweeping machinery on-site is to be used to regularly clear carpark and driveway areas.

Monitoring and Maintenance

A summary schedule of the various inspections, performance criteria and responses that shall be performed on Site is shown below.




Stormwater Management Procedures Table 5 - Monitoring and Maintenance of Stormwater Control Devices

Inspection Minimum Frequency

Performance Criteria

Response

Sediment Basins

Weekly, and prior to and following rainfall events

• 10% storage capacity available at all times to maintain adequate freeboard

• Basins are to be de-silted to ensure capacity is maintained at all times.

Inspect drainage lines including catch drains, contour drains and diversions

Weekly, and prior to and following rainfall events

• erosion in areas adjacent to water conveyancing structures

• eroded areas shall be rip rapped as soon as practicable

• overtopping of water conveyancing structures (i.e. clean water diversion drains) (identified by the scouring of the drain batters perpendicular to the direction of flow)

• eroded areas shall be repaired and stabilised.

Waste containers

Weekly • waste is stored in appropriate containers

• waste receptacles labelled

• ensure waste material is stored and disposed of properly and in accordance with conditions of the EA and legislative requirements.

Spill response stations

Weekly and following use

• equipment is properly maintained

• maintain equipment

• replace used equipment

Maintenance / refuelling area

Weekly • fuel, oil spills

• clean up fuel spills and investigate source

• equipment maintenance

• maintain equipment maintenance records

• fuel storage integrity maintained

• investigate and repair potential leaks

Auditing Stormwater quality testing results, practices and management reviews are required to be carried out annually to assess the implementation of the management strategies.




Stormwater Management Procedures Identification of Incident or Failure

Non-compliance with the performance criteria herein will be identified by:

• Build-up of sediment within sediment basins • Excessive sediment build-up on the Site • Excessive erosion on the Site • Release of contaminants from the Site • Poor vegetation establishment • Poorly maintained, damaged or failed ESC devices • Uncontrolled release from Site for events less than the design event • Non-compliant water quality being released from Site.

Corrective Action The Quarry Manager shall be responsible for identification of incident or failure and completion of corrective actions. Following identification of incident or failure, the source/cause is to be immediately located and the following measures implemented:

• Build-up of sediment in sediment basins – the material must be collected and disposed of in a manner that will not cause ongoing environmental nuisance or harm; then on-site ESC measures amended, where appropriate, to reduce the risk of further sedimentation.

• Excessive sediment build-up on the Site – collect and dispose of material, then amend up-slope drainage and/or erosion control measures as appropriate to reduce further occurrence.

• Severe or excessive rill erosion – investigate cause, control up-slope water movement, re-profile surface, cover dispersive soils with a minimum 100mm layer of non-dispersive soil, and stabilise with erosion control measures and vegetation as necessary.

• Release of construction material from the Site – collected and disposed of in a manner that will not cause ongoing environmental nuisance or harm; then inspect litter and waste receptors.

• Poor vegetation growth or soil coverage – plant new vegetation and/or mulch as required.

• Sediment control failure – replace and monitor more frequently. Regular failures may mean that the sediment control location, alignment or installation may need to be amended.

• Scour / erosion of sediment basin bunds will be required to be stabilised.

Internal Reporting A copy of all incidents and complaints will be stored at the Site within the incident and complaint register. All complaints and incidents are recorded internally.

External Reporting Reporting of non-compliance events including discharge of contaminants from the Site are to be reported to the Administering Authority and SEQ Water in accordance with conditions of the EA and the SEQ Water Development Guidelines.




4. Stormwater Management Plan Implementation

This SMP will be reviewed as required and will be updated as necessary to include revised operational activities and changes to disturbed areas.

4.1 Monitoring Management Measures

The following management measures will be implemented during facility operation:

• The Quarry Manager or authorised representative is to regularly inspect the stormwater management devices, particularly prior to forecasted wet weather and following major rainfall events to ensure that these devices are in good working order. All inspections are to be documented (including photos) and available on-site at all times.

• The Quarry Manager or authorised representative is to ensure that drains and paved surfaces are kept free of wastes or other material, especially materials which may impact on runoff water quality.

• The Quarry Manager shall carry out general surveillance to qualitatively assess stormwater releases from Site during discharge events.

• A surface water quality monitoring program may be implemented to assess performance from time to time. Any sampling conducted shall be undertaken in accordance with the Department of Environment and Heritage Protection’s Monitoring and Sampling Manual (2009) or more recent editions or supplements to that document by a suitability qualified person.

4.2 Auditing and Review

The effectiveness of the SMP will be reviewed as necessary (e.g. following a change in Site operations) and at least once every year. The review shall take into account changes to Site activities, available surface water monitoring results, any complaints, pollution incidents and any corrective actions taken.

4.3 Reporting and Responsibility

• The Quarry Manager will be responsible for ensuring that sediment basins and other stormwater devices constructed on the Site have adequate free water storage capacity.

• All complaints pertaining to water quality received will be recorded in the complaints register/log maintained on-site.

• The Quarry Manager or a suitably qualified consultant will prepare water monitoring records if and when required by the regulatory authority.

• Records, including results of any monitoring program undertaken on-site, complaints or incidents will be kept on-site for a minimum of five (5) years.

4.4 Identification of Incident or Failure

An incident or failure may include, but not be limited to:

• deterioration in surface water quality within waters discharged from Site • receipt of a stormwater quality release complaint • not maintaining on-site stormwater controls or treatment devices.

4.5 Corrective Action

If a discharge of contaminants occurs as a result of on-site operations, EHP and SEQ Water will require notification and an investigation will be conducted to identify appropriate action to resolve the issue to the fullest practicable extent.




5. Conclusion

This SMP outlines the appropriate treatment measures and operational procedures required to integrate stormwater management and administering authority compliance into daily operations and site activity. Specifically:

• Stormwater and ESC measures have been developed for the management and treatment of stormwater runoff from disturbed areas caused by proposed Site activities.

• Controls have been designed to treat contaminated stormwater runoff to ensure compliance with all EHP and SEQ Water guidelines.

Operational procedures outlined in this SMP will assist to ensure ongoing compliance with EHP conditions and the SEQ Water Development Guidelines as a minimum standard as well as seek further opportunities to exceed these standards.




6. Reference List

1. Department of Environment and Heritage Protection, Queensland Urban Drainage Manual, 2008

2. International Erosion Control Association, Best Practice Erosion and Sediment Control: Book 2 and Book 4, 2008.

3. Department of Environment and Heritage Protection, Stormwater Guideline: Environmentally Relevant Activities, 2014.

4. SEQ Water, SEQ Water Development Guidelines, 2012.

16/05/2017 2004.610.001

figures

10

SP145222

230

SP145222

7

RP117636

1

RP49263

226

CA31641

225

CA31641

1

RP118420

73

CSH2117

224

SP188932

341

CSH1945

224

CA31641

220

SP250792

248

SP260138

246

CA31773

14

CA311223

126

RP812185

124

CSH746

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QUARRY SUMP QS2

8.0m DEEP

V

SET

= 85.25ML

V

STOR

= 42.63ML

V

TOT

= 127.88ML

QUARRY SUMP QS3

8.0m DEEP

V

SET

= 45.50ML

V

STOR

= 22.75ML

V

TOT

= 68.25ML

QUARRY SUMP QS1

5.0m DEEP

V

SET

= 24.88ML

V

STOR

= 12.44ML

V

TOT

= 37.32ML

Catchment C2

28.66ha

Catchment C14

3.83ha

Catchment C4

4.99ha

B

u

a

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a

b

a

C

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Legend: N

S

W E

Scale:

1:7,500

Datum:

GDA94

Date:

2/03/2017

Drawing Number:

Z2004-007

1:7,500 at A3

0 150m 300m

Project:

Title:

Stormwater

Management Plan

Banffs Lane Coominya

Site Boundary

Cadastral Boundary

Easement Boundary

Cadastral Watercourse Boundary

Catch Drain

CD

Perimeter Bund / Bank

PB

Dirty Surface Water Flow

Catchment Boundary

Clean Surface Water Flow

16/05/2017 2004.610.001

Attachment 1 Clean Water Diversion Drain Calculations

Clean Water Diversion CW1

Channel Slope 0.03 m/m Depth (m) Discharge (m3/s)Mannings' n 0.05 0.00 0.00

0.10 0.08Maximum Water surface level 1 m 0.20 0.30

0.30 0.67Item Chainage (m) Elevation (m) 0.40 1.21

1 0 0.5 0.50 1.942 1.5 0 0.60 3.083 2.5 0 0.70 4.434 4 0.5 0.80 5.965 0.90 7.676 1.00 9.5578 Design flow 1.01 m3/s9 Water depth 0.36 m

10 Velocity 1.32 m/s1112131415161718192021222324252627282930313233343536373839404142434445464748495051525354

User inputs Rating Curve

0

0.1

0.2

0.3

0.4

0.5

0.6

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Elev

atio

n(m

)

Chainage (m)

Channel Cross Section

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00 2.00 4.00 6.00 8.00 10.00 12.00

Wat

erDe

pth

(m)

Discharge (cumecs)

Cross Section Rating Curve



0.13 0.64Maximum Water surface level 1.25 m 0.25 2.07


1 0 0.75 0.63 10.172 2.25 0 0.75 14.103 9.25 0 0.88 19.304 11.5 0.75 1.00 25.135 1.13 31.566 1.25 38.5678 Design flow 6.98 m3/s9 Water depth 0.50 m

10 Velocity 1.62 m/s1112131415161718192021222324252627282930313233343536373839404142434445464748495051525354


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 2 4 6 8 10 12 14

Elev

atio

n(m

)

Chainage (m)


0.00

0.20

0.40

0.60

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0.15 0.53Maximum Water surface level 1.5 m 0.30 1.71


1 0 1 0.75 8.352 3 0 0.90 11.553 12 0 1.05 15.444 15 1 1.20 20.255 1.35 25.566 1.50 31.3578 Design flow 9.38 m3/s9 Water depth 0.80 m

10 Velocity 1.03 m/s1112131415161718192021222324252627282930313233343536373839404142434445464748495051525354


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16/05/2017 2004.610.001

Attachment 2 Sediment Basin Calculations (Proposed)

Sediment Basin Storage Volume Estimation(Stormwater Guideline - Environmentally Relevant Activities - DEHP)

Project Name: Coominya QuarrySediment Basin: SB1

Vs = A * Cv * R (1 in 5; 24hr)

A = 265,100 m2

Equation 4.12 (QUDM)

Cv (pervious) = 0.75 Refer Table 4.9.2 (QUDM)F (imp) = 0.20 Adopted effective fraction imperviousA (imp) = 53020

Cv (composite) = 0.8

R (1 in 5; 24hr) = 129.12 mm Source: (BoM IFD)R (1 in 5; 24hr) = 0.12912 m

Vs = 27,384 m3

Vs = 27.38 ML

VSED = 0.5 * Vs

VSED = 13.69 ML

27.38 MLSediment Basin Requires a Sediment Storage Volume of 13.69 ML

41.08 ML

Sediment Basin Requires a Upper Settling Volume of

Total Sediment Basin Storage Volume is


Project Name: Coominya QuarrySediment Basin: SB2

Vs = A * Cv * R (1 in 5; 24hr)

A = 114,840 m2


Cv (pervious) = 0.70 Refer Table 4.9.2 (QUDM)F (imp) = 0.20 Adopted effective fraction imperviousA (imp) = 22968



Vs = 11,269 m3

Vs = 11.27 ML

VSED = 0.5 * Vs

VSED = 5.63 ML


16.90 ML




Project Name: Coominya QuarrySediment Basin: QS1

Vs = A * Cv * R (1 in 5; 24hr)

A = 253,566 m2


Cv (pervious) = 0.70 Refer Table 4.9.2 (QUDM)F (imp) = 0.20 Adopted effective fraction imperviousA (imp) = 50713.2



Vs = 24,883 m3

Vs = 24.88 ML

VSED = 0.5 * Vs

VSED = 12.44 ML


37.32 ML





Vs = A * Cv * R (1 in 5; 24hr)

A = 868,767 m2





Vs = 85,253 m3

Vs = 85.25 ML

VSED = 0.5 * Vs

VSED = 42.63 ML


127.88 ML





Vs = A * Cv * R (1 in 5; 24hr)

A = 463,658 m2





Vs = 45,499 m3

Vs = 45.50 ML

VSED = 0.5 * Vs

VSED = 22.75 ML


68.25 ML



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