3.0 engineering issues 4 - vpa
TRANSCRIPT
March 2014
Prepared for
Suite 4, 162 Drummond Street, Oakleigh, 3166 | (03) 9569 9402 | [email protected] | Certified to ISO 9001
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
CONTENTS PAGE 1.0 Introduction 3 2.0 Site Description 3 3.0 Engineering Issues 4
3.1 Roadworks 4
3.2 Stormwater drainage 5 Site minor drainage strategy proposal 6 Site major drainage system 8 Storm water quality issues 10
4.0 Recommended strategy 12 5.0 Conclusions 12 6.0 Disclaimer 12 ATTACHMENTS 1 APPENDIX A1 Wyndham North PSP boundaries plan 2 APPENDIX A2 Site locality Plan 3 APPENDIX B1 Site plan of re-establishment and feature survey 4 APPENDIX B2 Preliminary Conceptual Development Plan 5 APPENDIX C1 Road Hierarchy plan 6 APPENDIX C2 Road Topology plan (sections) 7 Appendix D Proposed MWC scheme works plan 8 Appendix E Drainage advice from Spiire Australia for AMEX land 9 Appendix F Drainage Strategy sub catchment plan 10 Appendix G Drainage catchment characteristics 11 Appendix H Preliminary drainage calculations
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
1.0` INTRODUCTION Taylors Stizza has been engaged to provide a stormwater drainage management strategy associated with the proposed development of a parcel of land located at 1121 Dohertys Road Tarneit as a residential subdivision. This land is included within the proposed Wyndham North PSP 1089 currently under consideration by Melbourne Planning Authority (MPA). MPA has advised a Section 96A Permit Application for development within this PSP shall be accepted and this drainage strategy forms part of the documentation requirements associated with the application. PSP1089 is centred about the major intersection of Dohertys and Tarneit Roads– general Melways Ref 359 D9. A copy of the MPA PSP boundaries plan, including PSP1089 is attached as Appendix A1. This report will essentially provide advice on
- key drainage management issues - stormwater runoff water quantity and quality issues - compliance of the strategy with current best practice management
objectives The Section 96A application relating to this site is for the central portion referred to as Precinct A – refer to plan in Appendix B2, Taylors Masterplan MP2 dated 19 August 2013. The balance site, Precinct B will be the subject of a separate application in future. This drainage strategy primarily considers Precinct A but also includes peripheral calculations relating to Precinct B that are pertinent. 2.0 SITE DESCRIPTION The subject site comprises some 84.75 Ha in total and is located at the south eastern corner of Dohertys and Tarneit Roads intersection.– a site locality plan is attached as Appendix A2. The site comprises two titles, namely
- the northern portion, Lot 1 on PS706302B comprising some 41.97 Ha and encumbered by an electricity transmission easement in the north western corner of some 64 m in width– road abuttal along Doherty Road is approximately 801 m and road abuttal along Tarneit Road is approximately 536 m.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
- The southern portion, Lot 5 on PS701126U comprising some 42.78 Ha with road abuttal along Tarneit Road of some 533 m and depth of approximately 801 m.
Site is generally flat for the most part and falls from Tarneit Road on the west towards the north eastern corner in the case of the northern portion and towards the south eastern corner in the case of the southern portion with a slight ridge running west to east approximately along the common title boundary. The site has been cleared over time and is currently covered by grass. There are no trees on site other than those around a homestead at the north eastern corner of the northern parcel and along the eastern site boundary to act as a wind row. The homestead and associated sheds and other buildings shall ultimately be demolished as part of the development of the site. The two roads abutting the site and providing access are currently constructed as two lane two way sealed roads to rural standards and are in reasonable condition. Their ultimate configuration are intended as 34 m divided arterial roads. A feature survey plan of the site is attached as Appendix B1. 3.0 ENGINEERING AND INFRASTRUCTURE 3.1 ROADWORKS The responsible authority for all road works is Wyndham City Council with referral to Vicroads for arterial road construction. Dohertys Road Dohertys Road to the east of Tarneit Road currently comprises a two lane two way sealed road to rural standards. The existing road at the eastern extremity of the site crosses Dry Creek (the creek also crosses the road at two other locations further east), a tributary of Skeleton Creek and is subject to periodic flooding. The draft PSP indicates a diversion and realignment of Dohertys Road into the subject site with future road upgrade to negate the flooding problem and this has been reflected in the development concept plan. The ultimate road classification of Dohertys Road is anticipated to be a 4 lane divided arterial road with central median within a 34 m wide road reservation. Development of the subject site will necessitate upgrade of Dohertys Road to urban standards, initially comprising the southern carriageway as a two lane two way road until future traffic volumes warrant duplication.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
Tarneit Road Tarneit Road abuttal of the project site is also currently constructed as a sealed two lane two way road to rural standards. The southern end of the subject site has recently undergone some upgrade works within the road reserve associated with the road crossing over the Regional Rail Link (RRL) reservation further south between the southern boundary of the southern parcel and Leakes Road. Tarneit Road overpass construction has been completed and is functional. The ultimate road classification of Tarneit Road is proposed as a 4 lane divided arterial road with central median within a 34 m wide road reservation. Development of the subject site will necessitate upgrade of Tarneit Road to urban standards, initially comprising the eastern carriageway as a two lane two way road until future traffic volumes warrant duplication. Internal Roads Internal roads within the development site shall be designed and constructed in accordance with Wyndham City Council and MPA standards as applicable. The cross sectional elements for each road shall be generally as per the MPA’s Engineering Design and Construction Manual in accordance with the road classification as designated by the project’s traffic engineer, primarily ranging from access lanes to an avenue and based on the anticipated traffic volumes along the particular road (vehicles per day). A road hierarchy master plan and Road Typology plan identifying type sections prepared by Taylors are included as Appendices C1 and C2 respectively – these sections were adopted to assess the overland flood carrying capacity for each road type used to convey these flows. Roads will need to be designed to accommodate both the minor and major drainage networks with overland flows being contained within road reserves (or dedicated drainage reserves where deemed necessary) with appropriate freeboard being provide to abutting allotments. Overland flow considerations shall be designed in accordance with MWC safety criteria and or GAA standards with respect to freeboard. 3.2 STORMWATER DRAINAGE The responsible authority for main drainage, floodplain and waterway management is Melbourne Water Corporation (MWC).
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
The subject principally site drains to three locations, the northern section to Dry Creek to the north eastern corner of the site, the middle section (essentially Precinct A) to Skeleton Creek to the east and the southern section towards the south eastern corner and ultimately to Skeleton Creek via Melbourne Water Drainage scheme works which includes piped works to Derrimut Road to the east and then via constructed waterway / low flow drain to Skeleton Creek. MWC have recently provided a copy of the scheme works proposals included for this site which is attached as Appendix D. Recent discussions with Spiire Australia, acting for Amex Corporation, the developers of the upstream land to the west of Tarneit Road, has resulted in advice being given with regards to their proposed drainage strategy which has impacts on the subject site and significantly influences the drainage strategy proposals for the site as assessed in this report. A copy of their advice is contained under Appendix E. Minor Drainage Strategy proposal. Minor drainage network for the catchment shall comply with Wyndham City Council, MPA and MWC standards and essentially provide for a 5 year Average Recurrence Interval (ARI) storm event. Given the Amex site has been divided into three sub-catchments from a drainage perspective and directed to separate outlets, there are impacts on the subject site which has necessitated the consideration of six sub- catchments in the assessment of the total site’s drainage strategy, sub-catchments C1 through to C6. The minor drainage proposal for the development site will comprise both Melbourne Water Scheme drain extensions together with subdivision drainage. Plans showing the proposed major internal minor drainage network layout together with drainage sub-catchment boundaries are attached as Appendix F. An analysis of the contributing external upstream drainage catchment (as supplied by Spiire) and proposed subdivision plan land use statistics has been undertaken to determine the post development 5 year ARI weighted co-efficient of runoff in conjunction with recommended fraction impervious values as identified in Table 16 of GAA Engineering Design and Construction Manual (April 2011) – refer to Appendix G for this analysis. A preliminary catchment minor drainage design (5 year ARI post development) has been prepared for the MWC scheme drains proposed through the site. This was undertaken to get a sense of catchment flows and likely drainage pipe sizes together with assessment of overland flows through the site. Pipe grades adopted for the analysis were based on existing surface levels at each node location
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
and not on any design levels – given the flat nature of the site, generally a pipe slope of 1 in 250 was adopted for the analysis (some sections were flatter) –refer to Appendix H for calculations. The following sub catchment results at their respective outlets are summarized from the analysis above:-
Sub- Catcment
dia - mm
C1+C2+C4 98.13 28.04 0.580 38.88 56.909 6.146 1800 C2 26.95 17.85 0.635 49.57 17.108 2.356 1200 C3 17.02 13.00 0.651 51.63 11.081 1.785 1050 C4 9.02 10.00 0.538 65.46 4.856 0.883 750 C5 31.00 28.20 0.586 38.75 18.178 1.967 1200 C6 13.41 11.25 0.656 62.05 8.797 1.516 1050
Site specific rainfall intensities were based on rainfall co-efficients derived from ARR87 – Volume 2 for Wyndham City Council. Catchments C1, C5 and C6 (from it’s outlet) contain a MWC scheme drain. Drainage calculations are based on using Colebrooke -White method with pipe roughness coefficients “k” of 0.6 mm for non MWC drains (ie council drains) and 1.5 mm for MWC scheme pipes – the drainage calculation sheet indicates the pipe roghness co-efficient adopted for each drain in calculation of pipe velocities and hence capacities. It should be pointed out that even though the catchment areas are large, external Amex Corporation contributions of 48.07 Ha and 25.44 Ha at sub-catchments C1 and C5 respectively create larger flows to be catered for throughout the subject site as these upstream flows are not retarded back to predevelopment flows. As an example, Amex drainage catchments directed at sub-catchment C1 totalling 48.07 ha have the following impacts on the subject site at Tarneit Road:-
- Undeveloped flows- tc = 34.5 min, c5= 0.25, I5 = 34.5 mm/hr -> q5 und = 1.152 cumecs
- Developed flows – tc = 21.1 min, c5w= 0.53, I5 = 45.4 mm/hr -> q5 dev = 3.222 cumecs
- Increased pipe flow through the developed site is thus 2.070 cumecs at the Tarneit Road end which must be catered for via larger pipes (MWC drain)
- Impact on q100 between developed and undeveloped is 8.394 less 2.86 cumecs respectively or an increase of 5.534 cumecs.
This issue will require further discussions with both MWC and Spiire to arrive at an equitable outcome.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
It is also worth noting that from past experiences with Wyndham City Council, they do not permit the conveyance of gap flows across major roads and their requirement has been to provide a Q100 drain crossing of major roads, such as Tarneit Road in this case. These Q100 pipes shall need to be given consideration by Spiire with respect to sizing, configuration and crossing over large services ( both existing and proposed) and reverting to a Q5 pipeline on the east side of Tarneit Road via a surcharge pit arrangement. Major Drainage System Wyndham City Council is the responsible drainage authority for all drainage matters within the site.
The design criteria for the conveyance of these flows (maximum velocity, maximum ponded depths, extent and width of water flows etc) shall be in accordance with council’s and or MWC’s requirements. All flows from major storm events (100 year ARI) shall be directed to the east and to Skeleton Creek with the exception of catchment C6 which will be directed to Dry Creek to the north eastern corner of the site and to the future waterway. Overland flows (comprising gap flows between 100 year and 5 year minor drainage flows) shall be conveyed along roadways that shall be designed in accordance with MWC safety criteria and GAA freeboard requirements. Safety criteria limits both the maximum velocity to 1.5 m/sec and average velocity times average depth ratio to 0.35 m/sec for flows along a roadway acting as a floodway. Freeboard requirements for allotments abutting an overland flow path are a minimum of 150 mm above the computed water level. For the development, a functional design of the overland flow paths for the 100 year ARI storm event has been prepared and is indicated on the drainage catchment plan – internal roads are used to convey these gap flows.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
A summary of Gap flow calculations at key internal drainage nodes is presented in the table below
Catchment Drain Area C5w tc I5 I100 Q5 Q100 Qgap
ID Node Ha. min mm/hr mm/hr cumec cumec cumec
C1 G 41.38
C1 F 47.80
C1 E 54.88
C1 D 62.54 0.599 26.90 39.79 82.80 5.463
10.770 5.487
2.686 1.668
4.863 3.016
6.244 3.867
0.635 19.27 47.60 99.90 2.260
5.935 3.675 C5 is the weighted 5 year ARI coefficient of runoff for the respective applicable catchment area and c100 has been adopted as 1.25 * c5 Considering peak gap flow calculations above at specific nodes, a review of the applicable road type sections and adoption of a longitudinal slope of 1 in 250 (0.40%) results in the following characteristics with respect to overland flows:
Node
E - D
D – C*
L - K
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
* Nodes D-C calculations are based on a minimum required road reservation width of 24.0 m with future Precinct B. ** Nodes K – J are within a 13.0 m road abutting a future reserve – the flood capacity of this road exceeds MWC’s safe flow criteria of vavg * davg <= 0.35 – an alternate analysis is presented in the above table recommending this as a 16 m local road which performs adequately. The calculations were undertaken via the use of PC – Convey V7.22 and assume an arbitrary crown RL of 100.00 for top water level illustrative purposes. The gap flow is based on Q100 – Q5 as calculated previously. The road capacities are adequate although the magnitude of the gap flow makes them flow full – refer to previous comments under the minor drainage system section relating to the design flows through the site from upstream AMEX catchments that are proposed to be discharged into the development site without any retardation back to undeveloped conditions – this has a significant impact on the development site and will need further discussions with MWC. Alternatively, it may be prudent to consider higher ARI’s to reduce the magnitude of the surface flows. The road reserves have adequate flow conveyance capacities however the required freeboard (150 mm) must be provided within the 2.0 m setback in the frontage of abutting allotments as permitted under GAA standards. Overland flows will discharge downstream at a number of locations and adequate provisions will need to be made for these flows – ultimately the discharge points are to Skeleton Creek and appropriate rock lined chutes will need to be provided to ensure bank stabilization is not compromised. Storm water quality issues Stormwater discharges from the site are generally required, by MWC to be treated in accordance with the principles established in “Urban Stormwater: Best Practice Environmental Management Guidelines” (Stormwater Committee Victoria, 1999) to attain the following pollution reduction targets as a minimum
- 100% reduction in litter/gross pollutants - 80% reduction in suspended solids loads - 45% reduction in Total Phosphorus loads - 45% reduction in Total Nitrogen loads
Melbourne Water encourages the use of WSUD initiatives such as sediment ponds, wetlands, bio-filtration systems, grassed swales, grey water re-use and rainwater tanks to be implemented in these types of developments as a means of achieving these outcomes prior to discharge into the drainage system, which in this case comprises Skeleton Creek.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
Limited opportunities appear to exist within the general site for implementation of effective water quality treatment measures in the form of say bio-retention trenches/vegetated swales or the like. It is not considered desirable to encumber the Active Open Space area with water quality treatment facilities, although the opportunity may exist to effect stormwater harvesting for irrigation purposes with the future development of this site by council. In any event, catchment wide water quality improvement measures either exist or are proposed within Skeleton Creek drainage corridor and it is therefore proposed the development site will meet it’s water quality obligations via Stormwater Qualty Offset contributions as allowed in the Skeleton Creek Drainage Scheme. As advised previously, the scale of the upstream catchments and the site topography dictates a number of drainage outlets to be provided - there are essentially four minor drainage system catchments (Q5) discharging Skeleton Creek. We have determined that some water quality measures may be provided within the developed site to achieve some quality outcomes via the use of the following strategies in each of the catchments within the development site –
- provision of rainwater tanks on each lot – allowed on the basis of 200 sq.m
roof area connected to a 5000 L tank plumbed into the toilet and laundry with daily domestic re-use of 120 l/day per lot
- provision of a pre treatment in line gross pollution trap at the downstream end
of the drainage network via a diversion chamber diverting the treatment flow of 3 month ARI (20% of Q5) with the balance design flow directed to the creek or waterway outlet – the GPT will filter litter (of size 20 mm or greater) and coarse sediments from the treatment flow
- consideration to some capture and harvesting of stormwater for irrigation
purposes within the active open space area that would form part of future development of facilities within that site.
We note that we do not have any advice from Spiire regarding proposals for stormwater quality measures likely to be introduced (if any ) within the AMEX landholdings upstream
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
4.0 Recommended Strategy The preceding sections of this report indicate the following key measures are required for a sustainable drainage management strategy for this development site:
a. Outfall drainage for the site shall be provided via discharge to Skeleton Creek or Dry Creek to the north east
b. No retardation of developed flows back to pre development rural flows is proposed for the development given it’s direct discharge to the creek
c. Site topography dictates minor drainage system network based on six sub catchments and the provision of four drainage outlets to Skeleton Creek
d. 100 year ARI surface (gap) flows can be totally accommodated within the site via roads acting as floodways – the calculated flows can be accommodated in accordance with MWC safety criteria and acceptable freeboard allowances as per GAA standards
e. The magnitude of the upstream drainage catchments draining at full development levels (without retardation) has significant impacts on the development site both in terms of the minor and major systems – further discussions may be required with MWEC and the upstream developer (AMEX) to assess whether an alternate discharge scenario may be provided from the AMEX site
f. Water quality treatment facilities are not provided within the development site as scheme wide water quality measures are either existing or shall be provided within the Skeleton Creek drainage corridor
5.0 Conclusions The preceding analysis provides advice and recommendations to ensure that a feasible surface water management strategy is achievable for the total development site that meets the stated objectives of addressing stormwater runoff issues. Whilst minimal on site water quality measures are proposed, water quality objectives can be met via catchment wide existing or proposed water quality proposals within the Skeleton Creek drainage corridor. The analysis has been prepared on the basis of advice from upstream consultants, MWC scheme proposals, GAA and Council standards and is considered to provide a feasible solution. 6.0 Disclaimer This report is based on preliminary information obtained from discussions with MWC, and consultants acting on behalf of AMEX Corporation together with in house expertise in determining drainage strategies for broad acre greenfield sites. All items are subject to confirmation and review on receipt of further advice from MPA / MWC and other key stakeholders pending outcomes of the Wyndham North
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
PSP 1091 exhibition process and formal applications for servicing conditions at time of development. The drainage management strategies identified in this report are thus subject to amendments resulting from the detailed design phase which may also include the use of other water sensitive design elements as deemed appropriate to provide similar outcomes. This report has been prepared in good faith specifically for The Corcoris Group and Taylors in support of a planning permit application to the MPA under Section 96A of the Planning and Environment Act 1987. This report is dated 18 March 2014.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX A1 WYNDHAM NORTH PSP BOUNDARIES PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX A2 1121 DOHERTYS ROAD - SITE LOCALITY PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX B1 PLAN OF RE-ESTABLISHMENT AND FEATURE SURVEY
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DOHERTYS ROAD
42.78ha
No.1121
MUNICIPALITY:Principal:
© This drawing remains the property of Taylors Development Strategists - Do not reproduce unlawfully
Sheet:
Revision:
P:\2270\ACAD\SURVEY\DETAIL PLANS\2270 D1 DWG | 1
Lengths are in metres
1121 DOHERTYS ROAD AND LOT 5 TARNEIT ROAD TARNEIT 3029
TCG (RM) Pty Ltd WYNDHAM CITY COUNCIL
RLI & MTK
• •
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX B2 CONCEPTUAL DEVELOPMENT PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX C1 ROAD HIERACHY PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX C2 PROPOSED ROAD TYPE SECTIONS
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28 35 7.5
concrete strip concrete strip
p:\2270\acad\urban design\concept plans\cad\2. august revision (mp2)\2270_concept mp02.dwg | 6. ROAD TYPOLOGY
NOT TO SCALE Job No.
Date.
2270 | MP 2 | ROAD TYPOLOGY 19/08/13 CNL AGT
PLAN NOTES • Plan is indicative only and has not yet had Council feedback or approval. • Boundaries and areas shown are subject to survey and design changes may
be required to consider onsite features, engineering & consultants advice. • Layout & lot yield may change as a result of strategic planning outcomes yet
to be finalized by the GAA and Council. • Further requirements may be needed but not finalized until the appropriate
investigations have been reported, including but not limited to: - Feature Survey, Flora and Fauna, Arboricultural Survey, - Archaeological, Engineering Services, Traffic Engineering.
SOURCE DATA • Surrounding boundary and contour information derived from supplied
VICMAP digital data.
ASSUMPTIONS • Assumed Road widening: Doherty's Rd: 14m, Tarneit Rd: 10m - TBC. • Road connections as shown require further investigation
DRAFT
Road Function Connector
Cycling Lanes 1.7m
Parking Lanes 2 x 2.3m
Cycling Lanes 1.7m
Cycling Lanes N/A
Cycling Lanes N/A
Notes:
Parking Lanes 1 x 2.3m unmarked
Cycling Lanes N/A
Footpath Width 1.5m
Notes:
Parking Lanes N/A
Cycling Lanes N/A
Notes:
Avenue 1 28 Avenue 2 24.6 Street 2 24 Street 1 20.6 Local road 16 Reserve/Service Road 13 Laneway 6.5
KEY MAP
Avenue 2 Cross section as per Avenue 1 without on road bike lanes
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
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APPENDIX D PROPOSED MWC SCHEME WORKS PLAN
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX E DRAINAGE ADVICE FROM SPIIRE AUSTRALIA RE AMEX CORPORATION
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From: Leigh Holmes [[email protected]] Sent: Friday, 24 January 2014 4:22 PM To: John Mitsios Cc: Elizabeth Hamila; [email protected]; Leah Strauch Subject: FW: Amex North - outfall locations Attachments: R01 012 Appendix - Catchment Plan.pdf; R01 012 Appendix - Rational calcs.pdf; R01
012 Outfall options summary.pdf
Hi John, Further to our meeting this morning please find attached documentation to underpin the AMEX drainage assumptions and assist with your drainage strategy. I am sure you understand that these calculations are still only preliminary and are subject to change upon further detail design. If you need any further clarifications please do not hesitate to contact myself or Liz
Leigh Holmes | Principal Consultant - Water Team Manager t +61 3 9993 7923 m +61 409 972 229 Level 4 | 469 La Trobe Street PO Box 16084 Melbourne VIC 8007 Australia
spiire.com.au client feedback survey
Please consider the environment before printing. The information contained in this email communication may be confidential. You should only disclose, re-transmit, copy, distribute, act in reliance on or commercialise the information if you are authorised to do so. Any views expressed in this email communication are those of the individual sender, except where the sender specifically states them to be the views of Spiire Australia Pty Ltd. Spiire Australia Pty Ltd does not represent, warrant or guarantee that the integrity of this communication has been maintained nor that the communication is free of errors, virus or interference.
From: Leah Strauch Sent: Friday, 24 January 2014 4:06 PM To: Leigh Holmes Subject: Amex North outfall locations Hi Leigh, Please find attached:
1. Summary of rationale for multiple outfalls and table of flows 2. PDF of rational calc worksheet 3. PDF of outfall catchments.
Cheers, Leah
Leah Strauch | Professional Engineer t +61 3 9993 7825 m Level 4 | 469 La Trobe Street PO Box 16084 Melbourne VIC 8007 Australia
spiire.com.au client feedback survey
Spiire Australia Pty Ltd ABN 55 050 029 635 T 61 3 9993 7888 spiire.com.au Level 3 469 La Trobe Street PO Box 16084 Melbourne Victoria 8007 Australia
:\13\137869\R01 012 Outfall options summary.docx Page 1
Project Name Amex North Project No. 137869
Subject Drainage outfall locations Reference R01 012
1. Introduction
Spiire was engaged by Amex Corporation to provide a drainage strategy for property 3 within the Truganina Development Services Scheme. The conveyance of stormwater flows (underground and overland) across the the DSS area requires thoughtful design due to the linear nature of catchments and relatively flat grades towards Skeleton Creek.
Spiire considered the impact and requirements on downstream properties when developing the Amex property drainage strategy.
2. MWC DSS Option
The original DSS included one discharge point/crossing from property 3 into the Tarneit Road reserve. With one discharge point, the Q100 flow at the crossing point is close to 11m3/s. As previously outlined, it would be complex to convey this flow through the catchment to Skeleton Creek in road reserves, and a drainage corridor is not a preferred solution.
3. Presented Alternate Scheme Option
Spiire has therefore proposed three discharge points to Tarneit Road:
• Outfall 1: Capturing an external catchment to the west and the northern portion of the site above the transmission line easement, and directing it northeast towards Skeleton Creek, most likely along a drainage corridor. This effectively removes this area from the DSS area.
• Outfall 2: Midway along the site. This outfall will be for gap/overland flow only.
• Outfall 3: This outfall will be for the minor (piped) system for the majority of the subject area, as well as the remaining gap/overland flow.
4. Outfall Flows
The calculated piped (Q5), total (Q100) and overland (Qgap) flows relevant to each outfall are presented below.
Q5 Q100 Qgap
Outfall 2 6.53 m3/s 4.44 m3/s
Outfall 3 3.21 m3/s 1.82 m3/s
60 83
.4 m
ut fa
ll op
tio ns
.x ls
P ag
e 1
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX F DRAINAGE SUBCATCHMENTS AND STRATEGY PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX G DRAINAGE CATCHMENT CHARACTERISTICS
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Area c5 Area c5
Commercial Zone 2.550 0.800 Electricity Easement 2.300 Dohertys Road realignment 1.000 0.700 Waterway area 1.150 0.000 Tarneit Road widening 0.540 0.700 0.190 0.700 Dohertys Road widening 0.350 0.700 Open Space 0.660 0.870 Active open Space - AOS 10.910 0.400 residential lots 17.950 0.680 road connector 2.010 0.700 local roads 8.450 0.600 balance area-lots / roads 35.810 0.650
Existing Tarneit Road 1.050 0.700 0.780 0.700 Existing Dohertys Road 0.590 0.700
AMEX catchments 10.710 0.610 25.440 0.600 as advised by Spiire 37.360 0.520
Totals 89.640 71.030
Total area 160.670
Notes
Above values derived from GAA Standards - Tables T16 and T17 Residential 1 and 2 zones - average lot size 410sq.m <450 sq.m
fraction impervious 0.75 - adopt c5 as 0.68 local roads - fraction impervious 0.65 average - adopt c5 as 0.60 major roads - fraction impervious 0.75 - adopt c5 as 0.70 commercial - BIZ - fraction impervious 0.90 - adopt c5 as 0.80
APPENDIX G
1121 DOHERTYS ROAD - TARNEIT
ZONE PRECINCT A PRECINCT B
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
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CONTENTS PAGE
Prepared for
Suite 4, 162 Drummond Street, Oakleigh, 3166 | (03) 9569 9402 | [email protected] | Certified to ISO 9001
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
CONTENTS PAGE 1.0 Introduction 3 2.0 Site Description 3 3.0 Engineering Issues 4
3.1 Roadworks 4
3.2 Stormwater drainage 5 Site minor drainage strategy proposal 6 Site major drainage system 8 Storm water quality issues 10
4.0 Recommended strategy 12 5.0 Conclusions 12 6.0 Disclaimer 12 ATTACHMENTS 1 APPENDIX A1 Wyndham North PSP boundaries plan 2 APPENDIX A2 Site locality Plan 3 APPENDIX B1 Site plan of re-establishment and feature survey 4 APPENDIX B2 Preliminary Conceptual Development Plan 5 APPENDIX C1 Road Hierarchy plan 6 APPENDIX C2 Road Topology plan (sections) 7 Appendix D Proposed MWC scheme works plan 8 Appendix E Drainage advice from Spiire Australia for AMEX land 9 Appendix F Drainage Strategy sub catchment plan 10 Appendix G Drainage catchment characteristics 11 Appendix H Preliminary drainage calculations
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
1.0` INTRODUCTION Taylors Stizza has been engaged to provide a stormwater drainage management strategy associated with the proposed development of a parcel of land located at 1121 Dohertys Road Tarneit as a residential subdivision. This land is included within the proposed Wyndham North PSP 1089 currently under consideration by Melbourne Planning Authority (MPA). MPA has advised a Section 96A Permit Application for development within this PSP shall be accepted and this drainage strategy forms part of the documentation requirements associated with the application. PSP1089 is centred about the major intersection of Dohertys and Tarneit Roads– general Melways Ref 359 D9. A copy of the MPA PSP boundaries plan, including PSP1089 is attached as Appendix A1. This report will essentially provide advice on
- key drainage management issues - stormwater runoff water quantity and quality issues - compliance of the strategy with current best practice management
objectives The Section 96A application relating to this site is for the central portion referred to as Precinct A – refer to plan in Appendix B2, Taylors Masterplan MP2 dated 19 August 2013. The balance site, Precinct B will be the subject of a separate application in future. This drainage strategy primarily considers Precinct A but also includes peripheral calculations relating to Precinct B that are pertinent. 2.0 SITE DESCRIPTION The subject site comprises some 84.75 Ha in total and is located at the south eastern corner of Dohertys and Tarneit Roads intersection.– a site locality plan is attached as Appendix A2. The site comprises two titles, namely
- the northern portion, Lot 1 on PS706302B comprising some 41.97 Ha and encumbered by an electricity transmission easement in the north western corner of some 64 m in width– road abuttal along Doherty Road is approximately 801 m and road abuttal along Tarneit Road is approximately 536 m.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
- The southern portion, Lot 5 on PS701126U comprising some 42.78 Ha with road abuttal along Tarneit Road of some 533 m and depth of approximately 801 m.
Site is generally flat for the most part and falls from Tarneit Road on the west towards the north eastern corner in the case of the northern portion and towards the south eastern corner in the case of the southern portion with a slight ridge running west to east approximately along the common title boundary. The site has been cleared over time and is currently covered by grass. There are no trees on site other than those around a homestead at the north eastern corner of the northern parcel and along the eastern site boundary to act as a wind row. The homestead and associated sheds and other buildings shall ultimately be demolished as part of the development of the site. The two roads abutting the site and providing access are currently constructed as two lane two way sealed roads to rural standards and are in reasonable condition. Their ultimate configuration are intended as 34 m divided arterial roads. A feature survey plan of the site is attached as Appendix B1. 3.0 ENGINEERING AND INFRASTRUCTURE 3.1 ROADWORKS The responsible authority for all road works is Wyndham City Council with referral to Vicroads for arterial road construction. Dohertys Road Dohertys Road to the east of Tarneit Road currently comprises a two lane two way sealed road to rural standards. The existing road at the eastern extremity of the site crosses Dry Creek (the creek also crosses the road at two other locations further east), a tributary of Skeleton Creek and is subject to periodic flooding. The draft PSP indicates a diversion and realignment of Dohertys Road into the subject site with future road upgrade to negate the flooding problem and this has been reflected in the development concept plan. The ultimate road classification of Dohertys Road is anticipated to be a 4 lane divided arterial road with central median within a 34 m wide road reservation. Development of the subject site will necessitate upgrade of Dohertys Road to urban standards, initially comprising the southern carriageway as a two lane two way road until future traffic volumes warrant duplication.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
Tarneit Road Tarneit Road abuttal of the project site is also currently constructed as a sealed two lane two way road to rural standards. The southern end of the subject site has recently undergone some upgrade works within the road reserve associated with the road crossing over the Regional Rail Link (RRL) reservation further south between the southern boundary of the southern parcel and Leakes Road. Tarneit Road overpass construction has been completed and is functional. The ultimate road classification of Tarneit Road is proposed as a 4 lane divided arterial road with central median within a 34 m wide road reservation. Development of the subject site will necessitate upgrade of Tarneit Road to urban standards, initially comprising the eastern carriageway as a two lane two way road until future traffic volumes warrant duplication. Internal Roads Internal roads within the development site shall be designed and constructed in accordance with Wyndham City Council and MPA standards as applicable. The cross sectional elements for each road shall be generally as per the MPA’s Engineering Design and Construction Manual in accordance with the road classification as designated by the project’s traffic engineer, primarily ranging from access lanes to an avenue and based on the anticipated traffic volumes along the particular road (vehicles per day). A road hierarchy master plan and Road Typology plan identifying type sections prepared by Taylors are included as Appendices C1 and C2 respectively – these sections were adopted to assess the overland flood carrying capacity for each road type used to convey these flows. Roads will need to be designed to accommodate both the minor and major drainage networks with overland flows being contained within road reserves (or dedicated drainage reserves where deemed necessary) with appropriate freeboard being provide to abutting allotments. Overland flow considerations shall be designed in accordance with MWC safety criteria and or GAA standards with respect to freeboard. 3.2 STORMWATER DRAINAGE The responsible authority for main drainage, floodplain and waterway management is Melbourne Water Corporation (MWC).
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
The subject principally site drains to three locations, the northern section to Dry Creek to the north eastern corner of the site, the middle section (essentially Precinct A) to Skeleton Creek to the east and the southern section towards the south eastern corner and ultimately to Skeleton Creek via Melbourne Water Drainage scheme works which includes piped works to Derrimut Road to the east and then via constructed waterway / low flow drain to Skeleton Creek. MWC have recently provided a copy of the scheme works proposals included for this site which is attached as Appendix D. Recent discussions with Spiire Australia, acting for Amex Corporation, the developers of the upstream land to the west of Tarneit Road, has resulted in advice being given with regards to their proposed drainage strategy which has impacts on the subject site and significantly influences the drainage strategy proposals for the site as assessed in this report. A copy of their advice is contained under Appendix E. Minor Drainage Strategy proposal. Minor drainage network for the catchment shall comply with Wyndham City Council, MPA and MWC standards and essentially provide for a 5 year Average Recurrence Interval (ARI) storm event. Given the Amex site has been divided into three sub-catchments from a drainage perspective and directed to separate outlets, there are impacts on the subject site which has necessitated the consideration of six sub- catchments in the assessment of the total site’s drainage strategy, sub-catchments C1 through to C6. The minor drainage proposal for the development site will comprise both Melbourne Water Scheme drain extensions together with subdivision drainage. Plans showing the proposed major internal minor drainage network layout together with drainage sub-catchment boundaries are attached as Appendix F. An analysis of the contributing external upstream drainage catchment (as supplied by Spiire) and proposed subdivision plan land use statistics has been undertaken to determine the post development 5 year ARI weighted co-efficient of runoff in conjunction with recommended fraction impervious values as identified in Table 16 of GAA Engineering Design and Construction Manual (April 2011) – refer to Appendix G for this analysis. A preliminary catchment minor drainage design (5 year ARI post development) has been prepared for the MWC scheme drains proposed through the site. This was undertaken to get a sense of catchment flows and likely drainage pipe sizes together with assessment of overland flows through the site. Pipe grades adopted for the analysis were based on existing surface levels at each node location
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
and not on any design levels – given the flat nature of the site, generally a pipe slope of 1 in 250 was adopted for the analysis (some sections were flatter) –refer to Appendix H for calculations. The following sub catchment results at their respective outlets are summarized from the analysis above:-
Sub- Catcment
dia - mm
C1+C2+C4 98.13 28.04 0.580 38.88 56.909 6.146 1800 C2 26.95 17.85 0.635 49.57 17.108 2.356 1200 C3 17.02 13.00 0.651 51.63 11.081 1.785 1050 C4 9.02 10.00 0.538 65.46 4.856 0.883 750 C5 31.00 28.20 0.586 38.75 18.178 1.967 1200 C6 13.41 11.25 0.656 62.05 8.797 1.516 1050
Site specific rainfall intensities were based on rainfall co-efficients derived from ARR87 – Volume 2 for Wyndham City Council. Catchments C1, C5 and C6 (from it’s outlet) contain a MWC scheme drain. Drainage calculations are based on using Colebrooke -White method with pipe roughness coefficients “k” of 0.6 mm for non MWC drains (ie council drains) and 1.5 mm for MWC scheme pipes – the drainage calculation sheet indicates the pipe roghness co-efficient adopted for each drain in calculation of pipe velocities and hence capacities. It should be pointed out that even though the catchment areas are large, external Amex Corporation contributions of 48.07 Ha and 25.44 Ha at sub-catchments C1 and C5 respectively create larger flows to be catered for throughout the subject site as these upstream flows are not retarded back to predevelopment flows. As an example, Amex drainage catchments directed at sub-catchment C1 totalling 48.07 ha have the following impacts on the subject site at Tarneit Road:-
- Undeveloped flows- tc = 34.5 min, c5= 0.25, I5 = 34.5 mm/hr -> q5 und = 1.152 cumecs
- Developed flows – tc = 21.1 min, c5w= 0.53, I5 = 45.4 mm/hr -> q5 dev = 3.222 cumecs
- Increased pipe flow through the developed site is thus 2.070 cumecs at the Tarneit Road end which must be catered for via larger pipes (MWC drain)
- Impact on q100 between developed and undeveloped is 8.394 less 2.86 cumecs respectively or an increase of 5.534 cumecs.
This issue will require further discussions with both MWC and Spiire to arrive at an equitable outcome.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
It is also worth noting that from past experiences with Wyndham City Council, they do not permit the conveyance of gap flows across major roads and their requirement has been to provide a Q100 drain crossing of major roads, such as Tarneit Road in this case. These Q100 pipes shall need to be given consideration by Spiire with respect to sizing, configuration and crossing over large services ( both existing and proposed) and reverting to a Q5 pipeline on the east side of Tarneit Road via a surcharge pit arrangement. Major Drainage System Wyndham City Council is the responsible drainage authority for all drainage matters within the site.
The design criteria for the conveyance of these flows (maximum velocity, maximum ponded depths, extent and width of water flows etc) shall be in accordance with council’s and or MWC’s requirements. All flows from major storm events (100 year ARI) shall be directed to the east and to Skeleton Creek with the exception of catchment C6 which will be directed to Dry Creek to the north eastern corner of the site and to the future waterway. Overland flows (comprising gap flows between 100 year and 5 year minor drainage flows) shall be conveyed along roadways that shall be designed in accordance with MWC safety criteria and GAA freeboard requirements. Safety criteria limits both the maximum velocity to 1.5 m/sec and average velocity times average depth ratio to 0.35 m/sec for flows along a roadway acting as a floodway. Freeboard requirements for allotments abutting an overland flow path are a minimum of 150 mm above the computed water level. For the development, a functional design of the overland flow paths for the 100 year ARI storm event has been prepared and is indicated on the drainage catchment plan – internal roads are used to convey these gap flows.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
A summary of Gap flow calculations at key internal drainage nodes is presented in the table below
Catchment Drain Area C5w tc I5 I100 Q5 Q100 Qgap
ID Node Ha. min mm/hr mm/hr cumec cumec cumec
C1 G 41.38
C1 F 47.80
C1 E 54.88
C1 D 62.54 0.599 26.90 39.79 82.80 5.463
10.770 5.487
2.686 1.668
4.863 3.016
6.244 3.867
0.635 19.27 47.60 99.90 2.260
5.935 3.675 C5 is the weighted 5 year ARI coefficient of runoff for the respective applicable catchment area and c100 has been adopted as 1.25 * c5 Considering peak gap flow calculations above at specific nodes, a review of the applicable road type sections and adoption of a longitudinal slope of 1 in 250 (0.40%) results in the following characteristics with respect to overland flows:
Node
E - D
D – C*
L - K
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
* Nodes D-C calculations are based on a minimum required road reservation width of 24.0 m with future Precinct B. ** Nodes K – J are within a 13.0 m road abutting a future reserve – the flood capacity of this road exceeds MWC’s safe flow criteria of vavg * davg <= 0.35 – an alternate analysis is presented in the above table recommending this as a 16 m local road which performs adequately. The calculations were undertaken via the use of PC – Convey V7.22 and assume an arbitrary crown RL of 100.00 for top water level illustrative purposes. The gap flow is based on Q100 – Q5 as calculated previously. The road capacities are adequate although the magnitude of the gap flow makes them flow full – refer to previous comments under the minor drainage system section relating to the design flows through the site from upstream AMEX catchments that are proposed to be discharged into the development site without any retardation back to undeveloped conditions – this has a significant impact on the development site and will need further discussions with MWC. Alternatively, it may be prudent to consider higher ARI’s to reduce the magnitude of the surface flows. The road reserves have adequate flow conveyance capacities however the required freeboard (150 mm) must be provided within the 2.0 m setback in the frontage of abutting allotments as permitted under GAA standards. Overland flows will discharge downstream at a number of locations and adequate provisions will need to be made for these flows – ultimately the discharge points are to Skeleton Creek and appropriate rock lined chutes will need to be provided to ensure bank stabilization is not compromised. Storm water quality issues Stormwater discharges from the site are generally required, by MWC to be treated in accordance with the principles established in “Urban Stormwater: Best Practice Environmental Management Guidelines” (Stormwater Committee Victoria, 1999) to attain the following pollution reduction targets as a minimum
- 100% reduction in litter/gross pollutants - 80% reduction in suspended solids loads - 45% reduction in Total Phosphorus loads - 45% reduction in Total Nitrogen loads
Melbourne Water encourages the use of WSUD initiatives such as sediment ponds, wetlands, bio-filtration systems, grassed swales, grey water re-use and rainwater tanks to be implemented in these types of developments as a means of achieving these outcomes prior to discharge into the drainage system, which in this case comprises Skeleton Creek.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
Limited opportunities appear to exist within the general site for implementation of effective water quality treatment measures in the form of say bio-retention trenches/vegetated swales or the like. It is not considered desirable to encumber the Active Open Space area with water quality treatment facilities, although the opportunity may exist to effect stormwater harvesting for irrigation purposes with the future development of this site by council. In any event, catchment wide water quality improvement measures either exist or are proposed within Skeleton Creek drainage corridor and it is therefore proposed the development site will meet it’s water quality obligations via Stormwater Qualty Offset contributions as allowed in the Skeleton Creek Drainage Scheme. As advised previously, the scale of the upstream catchments and the site topography dictates a number of drainage outlets to be provided - there are essentially four minor drainage system catchments (Q5) discharging Skeleton Creek. We have determined that some water quality measures may be provided within the developed site to achieve some quality outcomes via the use of the following strategies in each of the catchments within the development site –
- provision of rainwater tanks on each lot – allowed on the basis of 200 sq.m
roof area connected to a 5000 L tank plumbed into the toilet and laundry with daily domestic re-use of 120 l/day per lot
- provision of a pre treatment in line gross pollution trap at the downstream end
of the drainage network via a diversion chamber diverting the treatment flow of 3 month ARI (20% of Q5) with the balance design flow directed to the creek or waterway outlet – the GPT will filter litter (of size 20 mm or greater) and coarse sediments from the treatment flow
- consideration to some capture and harvesting of stormwater for irrigation
purposes within the active open space area that would form part of future development of facilities within that site.
We note that we do not have any advice from Spiire regarding proposals for stormwater quality measures likely to be introduced (if any ) within the AMEX landholdings upstream
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
4.0 Recommended Strategy The preceding sections of this report indicate the following key measures are required for a sustainable drainage management strategy for this development site:
a. Outfall drainage for the site shall be provided via discharge to Skeleton Creek or Dry Creek to the north east
b. No retardation of developed flows back to pre development rural flows is proposed for the development given it’s direct discharge to the creek
c. Site topography dictates minor drainage system network based on six sub catchments and the provision of four drainage outlets to Skeleton Creek
d. 100 year ARI surface (gap) flows can be totally accommodated within the site via roads acting as floodways – the calculated flows can be accommodated in accordance with MWC safety criteria and acceptable freeboard allowances as per GAA standards
e. The magnitude of the upstream drainage catchments draining at full development levels (without retardation) has significant impacts on the development site both in terms of the minor and major systems – further discussions may be required with MWEC and the upstream developer (AMEX) to assess whether an alternate discharge scenario may be provided from the AMEX site
f. Water quality treatment facilities are not provided within the development site as scheme wide water quality measures are either existing or shall be provided within the Skeleton Creek drainage corridor
5.0 Conclusions The preceding analysis provides advice and recommendations to ensure that a feasible surface water management strategy is achievable for the total development site that meets the stated objectives of addressing stormwater runoff issues. Whilst minimal on site water quality measures are proposed, water quality objectives can be met via catchment wide existing or proposed water quality proposals within the Skeleton Creek drainage corridor. The analysis has been prepared on the basis of advice from upstream consultants, MWC scheme proposals, GAA and Council standards and is considered to provide a feasible solution. 6.0 Disclaimer This report is based on preliminary information obtained from discussions with MWC, and consultants acting on behalf of AMEX Corporation together with in house expertise in determining drainage strategies for broad acre greenfield sites. All items are subject to confirmation and review on receipt of further advice from MPA / MWC and other key stakeholders pending outcomes of the Wyndham North
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
PSP 1091 exhibition process and formal applications for servicing conditions at time of development. The drainage management strategies identified in this report are thus subject to amendments resulting from the detailed design phase which may also include the use of other water sensitive design elements as deemed appropriate to provide similar outcomes. This report has been prepared in good faith specifically for The Corcoris Group and Taylors in support of a planning permit application to the MPA under Section 96A of the Planning and Environment Act 1987. This report is dated 18 March 2014.
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX A1 WYNDHAM NORTH PSP BOUNDARIES PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX A2 1121 DOHERTYS ROAD - SITE LOCALITY PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX B1 PLAN OF RE-ESTABLISHMENT AND FEATURE SURVEY
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DOHERTYS ROAD
42.78ha
No.1121
MUNICIPALITY:Principal:
© This drawing remains the property of Taylors Development Strategists - Do not reproduce unlawfully
Sheet:
Revision:
P:\2270\ACAD\SURVEY\DETAIL PLANS\2270 D1 DWG | 1
Lengths are in metres
1121 DOHERTYS ROAD AND LOT 5 TARNEIT ROAD TARNEIT 3029
TCG (RM) Pty Ltd WYNDHAM CITY COUNCIL
RLI & MTK
• •
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX B2 CONCEPTUAL DEVELOPMENT PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX C1 ROAD HIERACHY PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX C2 PROPOSED ROAD TYPE SECTIONS
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28 35 7.5
concrete strip concrete strip
p:\2270\acad\urban design\concept plans\cad\2. august revision (mp2)\2270_concept mp02.dwg | 6. ROAD TYPOLOGY
NOT TO SCALE Job No.
Date.
2270 | MP 2 | ROAD TYPOLOGY 19/08/13 CNL AGT
PLAN NOTES • Plan is indicative only and has not yet had Council feedback or approval. • Boundaries and areas shown are subject to survey and design changes may
be required to consider onsite features, engineering & consultants advice. • Layout & lot yield may change as a result of strategic planning outcomes yet
to be finalized by the GAA and Council. • Further requirements may be needed but not finalized until the appropriate
investigations have been reported, including but not limited to: - Feature Survey, Flora and Fauna, Arboricultural Survey, - Archaeological, Engineering Services, Traffic Engineering.
SOURCE DATA • Surrounding boundary and contour information derived from supplied
VICMAP digital data.
ASSUMPTIONS • Assumed Road widening: Doherty's Rd: 14m, Tarneit Rd: 10m - TBC. • Road connections as shown require further investigation
DRAFT
Road Function Connector
Cycling Lanes 1.7m
Parking Lanes 2 x 2.3m
Cycling Lanes 1.7m
Cycling Lanes N/A
Cycling Lanes N/A
Notes:
Parking Lanes 1 x 2.3m unmarked
Cycling Lanes N/A
Footpath Width 1.5m
Notes:
Parking Lanes N/A
Cycling Lanes N/A
Notes:
Avenue 1 28 Avenue 2 24.6 Street 2 24 Street 1 20.6 Local road 16 Reserve/Service Road 13 Laneway 6.5
KEY MAP
Avenue 2 Cross section as per Avenue 1 without on road bike lanes
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
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APPENDIX D PROPOSED MWC SCHEME WORKS PLAN
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX E DRAINAGE ADVICE FROM SPIIRE AUSTRALIA RE AMEX CORPORATION
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From: Leigh Holmes [[email protected]] Sent: Friday, 24 January 2014 4:22 PM To: John Mitsios Cc: Elizabeth Hamila; [email protected]; Leah Strauch Subject: FW: Amex North - outfall locations Attachments: R01 012 Appendix - Catchment Plan.pdf; R01 012 Appendix - Rational calcs.pdf; R01
012 Outfall options summary.pdf
Hi John, Further to our meeting this morning please find attached documentation to underpin the AMEX drainage assumptions and assist with your drainage strategy. I am sure you understand that these calculations are still only preliminary and are subject to change upon further detail design. If you need any further clarifications please do not hesitate to contact myself or Liz
Leigh Holmes | Principal Consultant - Water Team Manager t +61 3 9993 7923 m +61 409 972 229 Level 4 | 469 La Trobe Street PO Box 16084 Melbourne VIC 8007 Australia
spiire.com.au client feedback survey
Please consider the environment before printing. The information contained in this email communication may be confidential. You should only disclose, re-transmit, copy, distribute, act in reliance on or commercialise the information if you are authorised to do so. Any views expressed in this email communication are those of the individual sender, except where the sender specifically states them to be the views of Spiire Australia Pty Ltd. Spiire Australia Pty Ltd does not represent, warrant or guarantee that the integrity of this communication has been maintained nor that the communication is free of errors, virus or interference.
From: Leah Strauch Sent: Friday, 24 January 2014 4:06 PM To: Leigh Holmes Subject: Amex North outfall locations Hi Leigh, Please find attached:
1. Summary of rationale for multiple outfalls and table of flows 2. PDF of rational calc worksheet 3. PDF of outfall catchments.
Cheers, Leah
Leah Strauch | Professional Engineer t +61 3 9993 7825 m Level 4 | 469 La Trobe Street PO Box 16084 Melbourne VIC 8007 Australia
spiire.com.au client feedback survey
Spiire Australia Pty Ltd ABN 55 050 029 635 T 61 3 9993 7888 spiire.com.au Level 3 469 La Trobe Street PO Box 16084 Melbourne Victoria 8007 Australia
:\13\137869\R01 012 Outfall options summary.docx Page 1
Project Name Amex North Project No. 137869
Subject Drainage outfall locations Reference R01 012
1. Introduction
Spiire was engaged by Amex Corporation to provide a drainage strategy for property 3 within the Truganina Development Services Scheme. The conveyance of stormwater flows (underground and overland) across the the DSS area requires thoughtful design due to the linear nature of catchments and relatively flat grades towards Skeleton Creek.
Spiire considered the impact and requirements on downstream properties when developing the Amex property drainage strategy.
2. MWC DSS Option
The original DSS included one discharge point/crossing from property 3 into the Tarneit Road reserve. With one discharge point, the Q100 flow at the crossing point is close to 11m3/s. As previously outlined, it would be complex to convey this flow through the catchment to Skeleton Creek in road reserves, and a drainage corridor is not a preferred solution.
3. Presented Alternate Scheme Option
Spiire has therefore proposed three discharge points to Tarneit Road:
• Outfall 1: Capturing an external catchment to the west and the northern portion of the site above the transmission line easement, and directing it northeast towards Skeleton Creek, most likely along a drainage corridor. This effectively removes this area from the DSS area.
• Outfall 2: Midway along the site. This outfall will be for gap/overland flow only.
• Outfall 3: This outfall will be for the minor (piped) system for the majority of the subject area, as well as the remaining gap/overland flow.
4. Outfall Flows
The calculated piped (Q5), total (Q100) and overland (Qgap) flows relevant to each outfall are presented below.
Q5 Q100 Qgap
Outfall 2 6.53 m3/s 4.44 m3/s
Outfall 3 3.21 m3/s 1.82 m3/s
60 83
.4 m
ut fa
ll op
tio ns
.x ls
P ag
e 1
of 1
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX F DRAINAGE SUBCATCHMENTS AND STRATEGY PLAN
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Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
APPENDIX G DRAINAGE CATCHMENT CHARACTERISTICS
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Area c5 Area c5
Commercial Zone 2.550 0.800 Electricity Easement 2.300 Dohertys Road realignment 1.000 0.700 Waterway area 1.150 0.000 Tarneit Road widening 0.540 0.700 0.190 0.700 Dohertys Road widening 0.350 0.700 Open Space 0.660 0.870 Active open Space - AOS 10.910 0.400 residential lots 17.950 0.680 road connector 2.010 0.700 local roads 8.450 0.600 balance area-lots / roads 35.810 0.650
Existing Tarneit Road 1.050 0.700 0.780 0.700 Existing Dohertys Road 0.590 0.700
AMEX catchments 10.710 0.610 25.440 0.600 as advised by Spiire 37.360 0.520
Totals 89.640 71.030
Total area 160.670
Notes
Above values derived from GAA Standards - Tables T16 and T17 Residential 1 and 2 zones - average lot size 410sq.m <450 sq.m
fraction impervious 0.75 - adopt c5 as 0.68 local roads - fraction impervious 0.65 average - adopt c5 as 0.60 major roads - fraction impervious 0.75 - adopt c5 as 0.70 commercial - BIZ - fraction impervious 0.90 - adopt c5 as 0.80
APPENDIX G
1121 DOHERTYS ROAD - TARNEIT
ZONE PRECINCT A PRECINCT B
Drainage Management Strategy PSP 189 – 1121 Dohertys Road Tarneit Taylors Stizza Ref: 2332
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CONTENTS PAGE