Original source · versioned page text
Reference Document MCU22-0102 Cubo Consulting Letter Final
Engineering Buildable Solutions
Our Ref : 23122_LO_01/DB
Contact: Doug Black
21/12/2023
REFERENCE DOCUMENT
MCU22/0201
Kings Group (QLD) Pty Ltd NOOSA COUNCIL
PO Box 11, 15 AUGUST 2024
COOROY QLD, 4563
Attention: Joanne Hill
Dear Joanne,
PROPOSED CARWASH DEVELOPMENT, 34 ELM ST, COOROY QLD, 4563
Summary
This letter presents the results of a DRAINS drainage model including onsite detention for
the proposed development at the above address, and is intended as supporting information
for the Holistic Stormwater & Waste Water Management Plan, by TMC Building Design
Group, job number 20-032 CIV-Rev B, dated 11th May 2023.
The model found that the inclusion of 10.75m3 of onsite detention volume in the proposed
drainage arrangement will result in peak flow rates from the proposed development not
exceeding pre-development peak flow rates, for all events up to and including the 1% AEP
event with a 20% increase in rainfall intensity by 2100 for climate change.
The model was based on the drawings by CMG Consulting Engineers, 46143 rev C, issued
20/12/23.
Background
TMC have prepared a Water Management Plan for the proposed carwash development at
34 Elm St, Cooroy, stating that an effective reduction in impervious area draining from the
site will result in a reduction in peak flow rates from the site.
Noosa Council have requested more detail, specifically:
“A revised conservative assessment is required which demonstrates how peak flows will be
mitigated from the development to pre-existing levels, based on the rainwater tanks being
full.”
Existing Site Conditions
The existing site is currently unoccupied, with the previous motel having been demolished.
The site is surrounded on three side by roads with a bowling club on the eastern boundary.
The site falls generally to the southeast.
CUBO CONSULTING PTY LTD
ABN 46 610 277 462
Elizabeth Court, Shop 16, 30 Karalta Rd Erina 2250
PO BOX 315Avoca Beach NSW 2251
www.cubo.net.au
Phone 02 4326 0990
See the original
The page text is free to read. Viewing or downloading an original file needs an account.
Log in to see the originalSearchable page text hides email addresses. Original files are unchanged and may show email addresses.
Full text of the other 9 pages
Page 2
23122_LO_01 – 34 Elm St, Cooroy – King Group The total area within the property boundaries is 2014m2. Proposed Development A carwash and takeaway food outlet is proposed for the site. A 2m wide road widening easement on the northern boundary removes 80.4m2 from the finished site, and further council conditioned publicly accessible footway on the eastern boundary next to the bowling club removes 100.6m2 from the total site area, leaving a final effective total site area of 1,837m2. 845m2 of roof area is to be directed to 60kL of on-site rainwater tank capacity, with the overflow and surrounding paved areas to be directed to council’s piped stormwater system in Opal Street. Rainfall It is likely that the existing street storm water system was designed pre-2016, and so was designed using the ARR87 IFD rainfall rates to have sufficient capacity for the then existing motel and other upstream sites. The new development design uses the ARR2016 IFD rates and ARR2019 methodology to determine peak flowrates from the site. Fortunately, for the sake of comparison between pre and post development, for larger events the ARR87 rates for this location are very similar to the ARR2016 rates. The table below shows the comparable rainfall rates for event of 5 minutes duration. ARI 1 2 5 10 20 50 100 ARR87 mm/h 5 123 156 194 215 245 285 315 mins AEP 0.632 50% 20% 10% 5% 2% 1% ARR2016 mm/h 5 120 135 183 215 245 285 315 min Noosa Council have also requested that climate change be taken into account for the design, in this case described as a likely 20% increase on ARR2016 rainfall intensity rates by the year 2100. Onsite Detention An on-site detention arrangement is proposed to ensure peak flowrates from the site do not exceed pre-development peak flowrates. A revised stormwater drainage design proposes to provide 3x 20kL linked rainwater tanks collecting roof water, with the top portions of the tanks functioning as OSD. Keeping the invert of the OSD system 150mm above the invert of the adjacent gutter (108.28m AHD at the driveway in Opal St) and allowing for 500mm cover above the tanks (min FFL 109.35m AHD), a height of 420mm is available for detention. Based on the drawings provided by TMC, each tank has an area of 8.5m2, resulting in an available OSD volume of 3 x 0.42 x 8.5 = 10.75m3. This leaves 49m3 of storage volume for reuse on site in the car washing process. Civil, Structural & Hydraulic Engineering ⬧ Water Supply and Sewerage ⬧ Heritage ⬧ Planning ⬧ Environmental Page 2 of 4
Page 3
23122_LO_01 – 34 Elm St, Cooroy – King Group
Modelling
A model of the site was prepared using DRAINS Version 2023.11.8718.30178, with site
specific rainfall data published by the BoM.
Catchments used the Horton method with post-development catchments based on the
design drawings by TMC, which can be summarised as:
• 845m2 of roof area, 100% impervious
• 718m2 of pavement, 100% impervious
• 274m2 of landscaping, paved seating area, and small driveway areas, 38%
impervious
All roof areas are directed to the rainwater/OSD tanks, which discharge into the site drainage
network that also collects the pavement areas, directs them through the treatment train, then
discharges into the piped stormwater network in Opal St.
The various landscaping, paved seating areas, and small driveway areas outside the site
network are assumed to drain uncontrolled across the boundary.
The rainwater tanks were assumed to be full to the OSD outlet invert, with outflow controlled
by a 105mm orifice on the outlet of Pit 1.
Two further catchments were added to model the natural state – 1,857m2, 0% impervious –
and the previous development – 1,857m2, 77% impervious.
The model was run for several events from 1EY to 1% AEP, for 5 minutes duration to 2
hours.
Results
The table below shows the peak flow rates for each event from the site for the natural state,
previous development, and proposed arrangement.
Event Natural State Previous Post Comment
(L/s) Development Development
(L/s) (L/s)
1EY 37 47 33 Developed flows less than
predeveloped flows
50% 40 54 37 Developed flows less than
predeveloped flows
20% 63 78 53 Developed flows less than
predeveloped flows
10% 79 94 61 Developed flows less than
predeveloped flows
5% 93 109 68 Developed flows less than
predeveloped flows
2% 108 130 78 Developed flows less than
predeveloped flows
1% 121 146 83 Developed flows less than
predeveloped flows
1% x 1.2 148 178 97 Developed flows less than
predeveloped flows
DRAINS output for the model is attached.
The drainage design for the site can be further refined at the detailed design stage.
Civil, Structural & Hydraulic Engineering ⬧ Water Supply and Sewerage ⬧ Heritage ⬧ Planning ⬧ Environmental Page 3 of 4
Page 4
23122_LO_01 – 34 Elm St, Cooroy – King Group Conclusion The modelling suggests that for all events up to and including the 1% AEP +20%, the provision of on-site detention will ensure peak flowrates for the proposed development do not exceed peak flow rates from the current conditions or the natural state of the site. Modelling of downstream flooding conditions in Opal St would not be required as the peak flow rates from the site are reduced by the proposed development and will therefore improve pipe network flows through private land. This satisfies the request from Noosa Council. This letter is issued in accordance with our standard terms of engagement. This advice shall not be construed as relieving any other party of their legal responsibilities or contractual obligations Yours Faithfully, Vincent Francis Cubis MIEAust CPEng NER RPEQ 10086 Registered Professional Engineer - Engineers Australia (231327) Director Cubo Consulting Pty Ltd Civil, Structural & Hydraulic Engineering ⬧ Water Supply and Sewerage ⬧ Heritage ⬧ Planning ⬧ Environmental Page 4 of 4
Page 5
0.035 0.039 108.24 108.04 107.08 0.146 ° 90.121
Page 6
PIT / NODE DETAILS Version 15
Name Type Family Size Ponding Pressure Surface Max Pond Base Blocking x y Bolt-down id Part Full Inflow Pit is Internal Inflow is Minor Safe Major Safe
Volume Change Elev (m) Depth (m) Inflow Factor lid Shock Loss Hydrograph Width Misaligned Pond DepthPond Depth
(cu.m) Coeff. Ku (cu.m/s) (mm) (m) (m)
Pit11 OnGrade SIP 900 mm Sqre SIP 1.5 108.99 0 0 10904.7 39979.4 Yes 10 1 x Ku No New
Pit9 OnGrade SIP 900 mm Sqre SIP 1.5 108.35 0 0 11614.76 12060.86 Yes 8 1 x Ku No New
N44 Node 108.32 0 11962.15 6047.001 172 No
P8A OnGrade SIP 1200 x 900 mm SIP 1.5 108.75 0 0 20786.32 20354.95 No 12 1 x Ku No New
P8 OnGrade SIP 600 mm Sqre SIP 1.5 109 0 0 19599.84 22486.9 No 11 1 x Ku No New
P9 OnGrade SIP 600 mm Sqre SIP 1.5 108.75 0 0 18454.5 12250.97 No 7 1 x Ku No New
P7 OnGrade SIP 600 mm Sqre SIP 1.5 109.3 0 0 24549.84 29500.97 No 13 1 x Ku No New
N Diamond Node
Ln 109.5 0 78677.1 12994.54 175 No
N PreDev Node 108.32 0 12100.34 -2778.93 2231611 No
N Landscaping
Node 109.3 0 25480.11 40093.27 2730476 No
P1 Sag SIP 600 mm Sqre SIP7.866 1.5 109.6 0.15 0 0 55999.84 34975.97 No 1 1 x Ku No New 0.05 0.15
N Natural Node 108.32 0 21620.7 -3988.7 10149475 No
N P1 DUMMY Node 109.6 0 57713.32 29911.36 8692681 No
P2 OnGrade SIP 600 mm Sqre SIP 1.5 109.7 0 0 55999.84 21650.97 No 2 1 x Ku No New
P3 Sag SIP 600 mm Sqre SIP0.765 1.5 109.65 0.05 0 0 58743.62 12509.4 No 3 1 x Ku No New 0.05 0.05
P4 OnGrade SIP 600 mm Sqre SIP 1.5 109.65 0 0 33499.84 9990.973 No 4 1 x Ku No New
P5 - Treatment
OnGrade SIP 600 mm Sqre SIP 1.5 109.6 0 0 29949.84 8470.973 No 6 1 x Ku No New
P6 OnGrade SIP 600 mm Sqre SIP 1.5 109.2 0 0 26699.84 9990.973 No 5 1 x Ku No New
DETENTION BASIN DETAILS
Name Elev Surf. Area Not Used Outlet Type K Dia(mm) Centre RL Pit Family Pit Type x y HED Crest RL Crest Length(m)
id
OSD 108.425 1 Culvert 0.5 44912.91 36273.7 No 3728845
108.43 25.6
108.85 25.6
108.855 0.72
109.8 0.72
109.85 100
109.9 500
SUB-CATCHMENT DETAILS
Name Pit or Total Paved Grass Supp Paved Grass Supp Paved Grass Supp Paved Grass Supp Paved Grass Supp Lag Time Gutter Gutter Gutter Rainfall
Node Area Area Area Area Time Time Time Length Length Length Slope(%) Slope Slope Rough Rough Rough or Factor Length Slope FlowFactor Multiplier
(ha) % % % (min) (min) (min) (m) (m) (m) % % % (m) %
C P8 P8A 0.0335 100 0 0 5 5 2 0 1
C P7 P7 0.0093 100 0 0 5 5 2 0 1
C PreDev N PreDev 0.1837 77 23 0 5 5 2 0 1
C Landscaping
N Landscaping 0.0274 0 62 38 5 5 2 0 1
C Roofs OSD 0.0845 100 0 0 5 5 2 0 1
C P1 P1 0.0144 100 0 0 5 5 2 0 1
C Natural N Natural 0.1837 0 100 0 5 5 2 0 1
C p2 P2 0.006 100 0 0 5 5 2 0 1
C P3 P3 0.0086 100 0 0 5 5 2 0 1
PIPE DETAILS
Name From To Length U/S IL D/S IL Slope Type Dia I.D. Rough Pipe Is No. Pipes Chg From At Chg Chg Rl Chg RL etc
(m) (m) (m) (%) (mm) (mm) (m) (m) (m) (m) (m)
Pipe6 Pit11 Pit9 27.926 107.15 106.971 0.64 Concrete, under roads,
600 1% minimum
600 slope
0.013 New 1 Pit11 0
Pipe7 Pit9 N44 6.007 106.968 106.93 0.63 Concrete, under roads,
600 1% minimum
600 slope
0.013 New 1 Pit9 0
Pipe3 P8A P8 2.426 107.695 107.671 0.99 uPVC, under roads,150
1% minimum
154 slope 0.012 New 1 P8A 0
Pipe4 P8 P9 10.3 107.671 107.568 1 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P8 0
Pipe5 P9 Pit9 6.842 107.568 107.5 0.99 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P9 0
Pipe2 P7 P8 8.585 107.757 107.671 1 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P7 0
Pipe1 OSD P1 3.1 108.425 108.21 6.94 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 OSD 0
Pipe12 N P1 DUMMY P2 13.325 108.21 108.077 1 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 N P1 DUMMY 0
Pipe13 P2 P3 9.544 108.077 107.982 1 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P2 0
Pipe14 P3 P4 25.369 107.982 107.728 1 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P3 0
Pipe10 P4 P5 - Treatment 3.862 107.728 107.689 1.01 uPVC, under roads, 90
1% minimum
86 slope 0.012 New 1 P4 0
Pipe9 P4 P6 6.8 107.728 107.653 1.1 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P4 0
Pipe11 P5 - Treatment
P6 3.588 107.689 107.653 1 uPVC, under roads,150
1% minimum
154 slope 0.012 New 1 P5 - Treatment 0
Pipe8 P6 P9 8.549 107.653 107.568 0.99 uPVC, under roads,225
1% minimum
242 slope 0.012 New 1 P6 0
DETAILS of SERVICES CROSSING PIPES
Pipe Chg Bottom Height of Service
Chg Bottom Height of Service
Chg Bottom Height of Service
etc
(m) Elev (m) (m) (m) Elev (m) (m) (m) Elev (m) (m) etc
CHANNEL DETAILS
Name From To Type Length U/S IL D/S IL Slope Base WidthL.B. Slope R.B. Slope Manning Depth Roofed
(m) (m) (m) (%) (m) (1:?) (1:?) n (m)
OVERFLOW ROUTE DETAILS
Name From To Travel Spill Crest Weir Cross Safe Depth SafeDepth Safe Bed D/S Area id U/S IL D/S IL Length (m)
Time Level Length Coeff. C Section Major StormsMinor Storms
DxV Slope Contributing
(min) (m) (m) (m) (m) (sq.m/sec) (%) %
OF222 P8A N44 0.1 4 m wide pathway 0.3 0.15 0.4 2.13 0 411112 108.75 108.32 20.2
OF220 P7 P8A 0.1 7.5 m roadway with0.3
3% crossfall
0.15and barrier
0.4kerb 4.37 0 411109 109.3 108.75 12.6
OF2144 N Landscaping
N44 0.3 4 m wide pathway 0.3 0.15 0.4 1.86 0 2730479 109.3 108.4 48.4
OF7546 OSD P1 0.1 109.8 1.2 2 4 m wide pathway 0.3 0.15 0.4 0.43 0 8176507 109.8 109.75 11.5
OF1 P1 P2 0.2 4 m wide pathway 0.3 0.15 0.4 0.36 0 179 109.75 109.7 13.7
OF2 P2 P3 0.1 4 m wide pathway 0.3 0.15 0.4 0.52 0 180 109.7 109.65 9.7
OF3 P3 N Diamond Ln 0.1 4 m wide pathway 0.3 0.15 0.4 2.5 0 181 109.7 109.5 8
PIPE COVER DETAILS
Name Type Dia (mm) Safe Cover (m)
Cover (m)
Pipe6 Concrete, under roads,
600 1% minimum
0.6 slope
0.73
Pipe7 Concrete, under roads,
600 1% minimum
0.6 slope
0.74
Pipe3 uPVC, under roads,154
1% minimum
0.5 slope 0.9
Pipe4 uPVC, under roads,242
1% minimum
0.5 slope 0.93
Pipe5 uPVC, under roads,242
1% minimum
0.5 slope 0.6
Pipe2 uPVC, under roads,242
1% minimum
0.5 slope 1.08
Pipe1 uPVC, under roads,242
1% minimum
0.5 slope -0.25 Unsafe
Pipe12 uPVC, under roads,242
1% minimum
0.5 slope 1.14
Pipe13 uPVC, under roads,242
1% minimum
0.5 slope 1.38
Pipe14 uPVC, under roads,242
1% minimum
0.5 slope 1.42
Pipe10 uPVC, under roads, 86
1% minimum
0.5 slope 1.82
Pipe9 uPVC, under roads,242
1% minimum
0.5 slope 1.3
Pipe11 uPVC, under roads,154
1% minimum
0.5 slope 1.39
Pipe8 uPVC, under roads,242
1% minimum
0.5 slope 0.93
This model has no pipes with non-return valves
Page 7
DRAINS results prepared from Version 2023.11.8718.30178
PIT / NODE DETAILS Version 8
Name Max HGL Max Pond Max SurfaceMax Pond Min Overflow Constraint
HGL Flow Arriving
Volume Freeboard (cu.m/s)
(cu.m/s) (cu.m) (m)
Pit11 107.15 0 1.84 None
Pit9 107.13 0 1.22 None
N44 107.06 0.015
P8A 107.93 0.024 0.82 0 None
P8 107.84 0 1.16 None
P9 107.81 0 0.94 None
P7 107.84 0.006 1.46 0 Inlet Capacity
N Landscaping 109.31 0.016
P1 109.71 109.71 0.01 4.1 0 0.027 Outlet System
N P1 DUMMY 108.33 0
P2 108.25 0.004 1.45 0 None
P3 108.17 109.66 0.006 0 1.48 0 Inlet Capacity
P4 107.93 0 1.72 None
P5 - Treatment107.88 0 1.72 None
P6 107.88 0 1.32 None
SUB-CATCHMENT DETAILS
Name Max Paved Grassed Paved Grassed Supp. Due to Storm
Flow Q Max Q Max Q Tc Tc Tc
(cu.m/s) (cu.m/s) (cu.m/s) (min) (min) (min)
C P8 0.019 0.019 0 5 5 2 10% AEP, 5 min burst, Storm 1
C P7 0.005 0.005 0 5 5 2 10% AEP, 5 min burst, Storm 1
C PreDev 0.094 0.08 0.014 5 5 2 10% AEP, 5 min burst, Storm 1
C Landscaping 0.013 0 0.013 5 5 2 10% AEP, 10 min burst, Storm 8
C Roofs 0.048 0.048 0 5 5 2 10% AEP, 5 min burst, Storm 1
C P1 0.008 0.008 0 5 5 2 10% AEP, 5 min burst, Storm 1
C Natural 0.079 0 0.079 5 5 2 10% AEP, 10 min burst, Storm 4
C p2 0.003 0.003 0 5 5 2 10% AEP, 5 min burst, Storm 1
C P3 0.005 0.005 0 5 5 2 10% AEP, 5 min burst, Storm 1
PIPE DETAILS
Name Max Q Max V Max U/S Max D/S Due to Storm
(cu.m/s) (m/s) HGL (m) HGL (m)
Pipe6 0 0 107.15 107.129 10% AEP, 5 min burst, Storm 1
Pipe7 0.05 1.11 107.129 107.059 10% AEP, 15 min burst, Storm 5
Pipe3 0.019 1.03 107.862 107.838 10% AEP, 5 min burst, Storm 1
Pipe4 0.023 0.71 107.831 107.814 10% AEP, 5 min burst, Storm 1
Pipe5 0.05 1.42 107.75 107.672 10% AEP, 15 min burst, Storm 5
Pipe2 0.005 0.35 107.843 107.838 10% AEP, 5 min burst, Storm 1
Pipe1 0.04 0.87 109.724 109.706 10% AEP, 10 min burst, Storm 6
Pipe12 0.027 1.22 108.329 108.253 10% AEP, 30 min burst, Storm 9
Pipe13 0.03 1.03 108.222 108.17 10% AEP, 15 min burst, Storm 8
Pipe14 0.033 1.12 108.131 107.934 10% AEP, 15 min burst, Storm 7
Pipe10 0.004 0.61 107.911 107.882 10% AEP, 15 min burst, Storm 8
Pipe9 0.03 0.8 107.903 107.879 10% AEP, 15 min burst, Storm 8
Pipe11 0.004 0.19 107.88 107.879 10% AEP, 20 min burst, Storm 4
Pipe8 0.034 0.87 107.842 107.814 10% AEP, 15 min burst, Storm 8
CHANNEL DETAILS
Name Max Q Max V Due to Storm
(cu.m/s) (m/s)
OVERFLOW ROUTE DETAILS
Name Max Q U/S Max Q D/S Safe Q Max D Max DxV Max Width Max V Due to Storm
OF222 0 0 1.325 0 0 0 0
OF220 0 0 0.642 0 0 0 0
OF2144 0.011 0.011 1.239 0.023 0.01 4 0.35 10% AEP, 10 min burst, Storm 6
OF7546 0 0 0.596 0 0 0 0
OSD Ori 0.027 0.027 10% AEP, 30 min burst, Storm 9
OF1 0 0 0.545 0 0 0 0
OF2 0 0 0.655 0 0 0 0
OF3 0 0 1.436 0 0 0 0
DETENTION BASIN DETAILS
Name Max WL MaxVol Max Q Max Q Max Q
Total Low Level High Level
OSD 109.75 11.5 0.04 0.04 0
Run Log for 23122 v4
{\colortbl;\red0\green0\blue0;\red192\green0\blue0;}Run Log for 23122 v4.drn - DRAINS run at 12:21:53 on 21/12/2023 using Watercom Drains v2023.11.8718.30178
Page 8
Upwelling occurred at: P1 Flows were safe in all overflow routes. These sag pits have unsafe water levels for minor storms: P1
Page 9
DRAINS results prepared from Version 2023.11.8718.30178
PIT / NODE DETAILS Version 8
Name Max HGL Max Pond Max SurfaceMax Pond Min Overflow Constraint
HGL Flow Arriving
Volume Freeboard (cu.m/s)
(cu.m/s) (cu.m) (m)
Pit11 107.15 0 1.84 None
Pit9 107.15 0 1.2 None
N44 107.08 0.021
P8A 108.19 0.032 0.56 0 Inlet Capacity
P8 108.01 0 0.99 None
P9 107.95 0 0.8 None
P7 108.01 0.008 1.29 0.002 Inlet Capacity
N Landscaping 109.31 0.022
P1 109.77 109.77 0.032 7.9 0 0.028 Outlet System
N P1 DUMMY 108.35 0
P2 108.31 0.016 1.39 0.002 Inlet Capacity
P3 108.24 109.66 0.008 0 1.41 0 Inlet Capacity
P4 108.09 0 1.56 None
P5 - Treatment108.04 0 1.56 None
P6 108.03 0 1.17 None
SUB-CATCHMENT DETAILS
Name Max Paved Grassed Paved Grassed Supp. Due to Storm
Flow Q Max Q Max Q Tc Tc Tc
(cu.m/s) (cu.m/s) (cu.m/s) (min) (min) (min)
C P8 0.028 0.028 0 5 5 2 1% AEP, 5 min burst, Storm 1
C P7 0.008 0.008 0 5 5 2 1% AEP, 5 min burst, Storm 1
C PreDev 0.146 0.119 0.026 5 5 2 1% AEP, 5 min burst, Storm 1
C Landscaping 0.019 0 0.019 5 5 2 1% AEP, 10 min burst, Storm 3
C Roofs 0.071 0.071 0 5 5 2 1% AEP, 5 min burst, Storm 1
C P1 0.012 0.012 0 5 5 2 1% AEP, 5 min burst, Storm 1
C Natural 0.121 0 0.121 5 5 2 1% AEP, 10 min burst, Storm 4
C p2 0.005 0.005 0 5 5 2 1% AEP, 5 min burst, Storm 1
C P3 0.007 0.007 0 5 5 2 1% AEP, 5 min burst, Storm 1
PIPE DETAILS
Name Max Q Max V Max U/S Max D/S Due to Storm
(cu.m/s) (m/s) HGL (m) HGL (m)
Pipe6 0 0 107.154 107.154 1% AEP, 10 min burst, Storm 7
Pipe7 0.065 1.2 107.154 107.078 1% AEP, 10 min burst, Storm 7
Pipe3 0.029 1.56 108.059 108.012 1% AEP, 5 min burst, Storm 1
Pipe4 0.033 0.71 107.978 107.951 1% AEP, 5 min burst, Storm 1
Pipe5 0.066 1.58 107.81 107.706 1% AEP, 10 min burst, Storm 7
Pipe2 0.006 0.12 108.013 108.012 1% AEP, 5 min burst, Storm 1
Pipe1 0.056 1.21 109.801 109.773 1% AEP, 5 min burst, Storm 1
Pipe12 0.029 1.07 108.347 108.305 1% AEP, 5 min burst, Storm 1
Pipe13 0.034 0.86 108.272 108.243 1% AEP, 25 min burst, Storm 9
Pipe14 0.039 0.91 108.194 108.094 1% AEP, 25 min burst, Storm 9
Pipe10 0.004 0.64 108.068 108.037 1% AEP, 25 min burst, Storm 3
Pipe9 0.035 0.8 108.054 108.032 1% AEP, 25 min burst, Storm 9
Pipe11 0.004 0.2 108.034 108.032 1% AEP, 30 min burst, Storm 1
Pipe8 0.039 0.85 107.984 107.951 1% AEP, 25 min burst, Storm 9
CHANNEL DETAILS
Name Max Q Max V Due to Storm
(cu.m/s) (m/s)
OVERFLOW ROUTE DETAILS
Name Max Q U/S Max Q D/S Safe Q Max D Max DxV Max Width Max V Due to Storm
OF222 0 0 1.449 0 0 0 0
OF220 0.002 0.002 0.77 0.02 0.02 0.24 0.78 1% AEP, 5 min burst, Storm 1
OF2144 0.018 0.018 1.445 0.025 0.01 4 0.43 1% AEP, 10 min burst, Storm 5
OF7546 0.014 0.014 1.503 0.026 0.01 4 0.32 1% AEP, 10 min burst, Storm 7
OSD Ori 0.028 0.028 1% AEP, 25 min burst, Storm 9
OF1 0.007 0.007 1.506 0.021 0.01 4 0.25 1% AEP, 25 min burst, Storm 4
OF2 0.002 0.002 1.501 0.013 0 1.33 0.26 1% AEP, 25 min burst, Storm 9
OF3 0 0 1.446 0 0 0 0
DETENTION BASIN DETAILS
Name Max WL MaxVol Max Q Max Q Max Q
Total Low Level High Level
OSD 109.84 12.4 0.069 0.056 0.014
Run Log for 23122 v4
{\colortbl;\red0\green0\blue0;\red192\green0\blue0;}Run Log for 23122 v4.drn - DRAINS run at 12:22:33 on 21/12/2023 using Watercom Drains v2023.11.8718.30178
Page 10
Upwelling occurred at: P1 The maximum pond depth in these sag pits is unsafe: P1\line Flows were safe in all overflow routes.