city ditch hydraulic analysis · trapezoidal city ditch we are assuming n= 0.05, for ditch portion...
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FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
PROPOSED RESIDENTIAL DEVELOPMENT – 143 BLUEWATER PLACE & 105 AVONDALE COURT
CITY OF BURLINGTON, ONTARIO
Project No: 13215
CITY DITCH HYDRAULIC ANALYSIS
Prepared For:
BLOOMFIELD DEVELOPMENTS INC.
Prepared By:
The Odan/Detech Group Inc.
ISSUED: August 21, 2019
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
TABLE OF CONTENTS
1.0 BACKGROUND .................................................................................................................. 1
2.0 STUDY METHODOLOGY ................................................................................................... 1
3.0 SYSTEM MODEL ............................................................................................................... 2
4.0 MODEL INPUT AND RESULTS .......................................................................................... 3
5.0 CONCLUSIONS ................................................................................................................ 11
6.0 REFERENCES .................................................................................................................. 12
LIST OF TABLES Table 1 – Hydrology parameters for runoff determination ................................................................ 3 Table 2 – Node (MH) information .................................................................................................... 3 Table 3 – Link (pipe) information ..................................................................................................... 3 Table 4 – Nodal Results .................................................................................................................. 4 Table 5 – Link Results ..................................................................................................................... 4
LIST OF FIGURES
Exhibit 1 - Global XPSWMM Model ................................................................................................ 2 Exhibit 2 – Profile plot from MH 1 to Lake - 5year storm ................................................................. 5 Exhibit 3 – Profile plot from MH 1 to Lake - 100year storm ............................................................. 6 Exhibit 4 – Profile plot from MH 1 to Lake 100 year storm with 20% more flow added to MH-1 ...... 7 Exhibit 5 – Profile plot from MH 1 to Lake 100 year storm with 40% more flow added to MH-1 ...... 8 Exhibit 6 – Hydrology runoff at select nodes ................................................................................. 9
APPENDIX A Aerial View of Site Figure 1 Overland flow to City Ditch tributary area map Figure 2 Flood line map
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 1
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
1.0 BACKGROUND
The property under study is a 1.62 ha site on the south side of Lakeshore Road in the City of Burlington. The site is bounded by Lake Ontario to the south, existing residential development to the west, existing residential to the east and existing Lakeshore Road to the north. The municipal addresses for the site are 105 Avondale Court and 143 Blue Water Place lane. Presently the development on the site is two single family homes with related parking along a common laneway. It is proposed to construct a new low rise residential building along with underground parking. There is a City drainage ditch in the area of concern that runs parallel with Avondale Court. This ditch runs along the southeast portion of the subject site and discharges to Lake Ontario. In addition to the overland flow this ditch accepts flow from a City sewer system. Discussions between the City and the Developers resulted in an agreement that the Developer would undergo an analysis of the City Ditch. This report will evaluate the hydraulic impact of the existing flow from the City Ditch on the subject property. The report will analyze the flows to the ditch, the subsequent hydraulic grade lines (HGL), erosion effects and flood impacts. Refer to Figure 1in appendix A for the location of the City Ditch relative to the Subject Site.
2.0 STUDY METHODOLOGY
The Study is not intended to be a rework of the City design but rather a detailed analysis of the existing City Ditch based on info given to Odan/Detech by the City and assumptions made by Odan/Detech. Odan/Detech created a dynamic model from info given by the City. The info given are various PDF Plan and Profile drawings. The info was in imperial units and converted into metric by Odan/Detech. ASSUMPTIONS:
The inverts were taken from the profiles by Kerry T. Howe Limited (transfer to sanitary operating Map) dated April 23, 1981.
Additional topographical info by Mackay, Mackay & Peters Limited.
The tributary areas for the 54” (1372 Ø storm sewer) is unknown and would be a large task to undergo. It was agreed with the City that the flow to the ditch from this sewer would be limited to the full barrel flow of the pipe. The full barrel flow is a constant and thus applies to the 5 year and 100 year overland flows to the ditch. The full barrel flow is 2.61 cms.
The overland flow area to the ditch was estimated using given topology and walking the site. This flow was lumped at the beginning of the channel (conservative).
The creek culvert crossing is a 1200 Ø CSP pipe with a head wall. We assumed an entrance loss of 0.5 and an exit loss of 1.0. This is in keeping with the MTO Drainage Manual culvert design section.
Trapezoidal City Ditch we are assuming n= 0.05, for ditch portion near the culvert crossing n=0.05, channels downstream of culvert n=0.08. These manning values are in keeping with Conservation Authorities design criteria.
Assume City Ditch is built similar to that shown on the Kerry T. Howe Limited plan.
Lake 100 year level and 100 year storm event do not occur simultaneously. The remainder of the study will display the results of the analysis of XPSWMM. The results will be in the form of tables and profile plots. A discussion of the results will be given.
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 2
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
3.0 SYSTEM MODEL
Exhibit 1 - Global XPSWMM Model
EX. 54” (1372) STM
SEWER FROM
AVONDALE COURT
EXISTING
HEADWALL
EX. Trapezoidal
channel. Bottom 1.5m,
sides 2:1 and 3:1
EX. Trapezoidal
channel. Bottom 2.0m,
sides 3:1 and 3:1
transition from straight
channel to culvert
EX. 1200 CSP with
road on top modelled as
a multilink → culvert
pipe plus channel
above for overflows
EX. Natural channel with
gabion walls. Irregular
shape. Section varies along
length. Chose the most
conservative section
Hydrology entered at this
location for overland flow to
channel.
EX. Natural channel with
gabion walls. Irregular
shape. Section varies along
length. Chose the most
conservative section
Pipe full barrel flow
entered here.
Outfall to Lake at
invert 75.40m
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 3
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
4.0 MODEL INPUT AND RESULTS
Table 1 – Hydrology parameters for runoff determination
Table 2 – Node (MH) information
Table 3 – Link (pipe) information
Name Storm Subcatchment
Area
ha
Width
m Slope
Impervious
Percentage
%
Pervious
Area Curve
Number
Pervious
Depression
storage
Depth mm
Infiltration
Reference
Hydrology
Methods
HW-1 5 yr 1 7.180 164.1 0.012 35.0 80 5 SCS SWMM runoff
7.180
Name
Ground
Elevation
(Spill Crest)
m
Invert
Elevation m
CULV-OUT 80.02 77.29
CULV-IN 80.10 77.43
HW-1 80.50 78.46
MH-1 81.60 78.57
Node-2 78.50 76.13
Node-1 79.89 77.72
Lake Ontario 77.00 75.40
Downstream
Node Name
Upstream
Node
Name
trapezoidal
bott width &
side slopes
Diameter
(Height) m
Conduit
Slope %Roughness Length m Shape
Downstream
Invert
Elevation m
Upstream
Invert
Elevation m
Node-2 CULV-OUT 1.375 3.87 0.08 32.0 Natural 76.13 77.29
CULV-OUT CULV-IN 1.200 1.08 0.024 13.0 Circular 77.29 77.43
CULV-OUT CULV-IN 1.5m, 60:1 60:1 0.300 0.62 0.04 13.0 Trapezoidal 79.72 79.80
Node-1 HW-1 1.5m, 3:1 2:1 1.200 0.76 0.05 97.5 Trapezoidal 77.72 78.46
HW-1 MH-1 1.372 0.22 0.013 50.3 Circular 78.46 78.57
Lake Ontario Node-2 1.375 1.46 0.08 50.0 Natural 75.40 76.13
CULV-IN Node-1 2.0m, 3:1 3:1 1.200 1.16 0.05 25.0 Trapezoidal 77.43 77.72
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 4
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Table 4 – Nodal Results
Table 5 – Link Results
Note - Table 4 and 5 results are for full barrel flow at MH 1.
Name Storm Freeboard
m
Max Water
Depth m
Max Water
Elevation m
CULV-OUT 5yr-4hr-Chi 1.87 0.86 78.15
CULV-OUT 100yr-4hr-Chi 1.84 0.90 78.19
CULV-IN 5yr-4hr-Chi 1.04 1.63 79.06
CULV-IN 100yr-4hr-Chi 0.85 1.82 79.25
HW-1 5yr-4hr-Chi 1.13 0.91 79.37
HW-1 100yr-4hr-Chi 1.03 1.01 79.47
MH-1 5yr-4hr-Chi 2.05 0.98 79.55
MH-1 100yr-4hr-Chi 1.99 1.04 79.61
Node-2 5yr-4hr-Chi 1.37 1.00 77.13
Node-2 100yr-4hr-Chi 1.33 1.04 77.17
Node-1 5yr-4hr-Chi 0.82 1.35 79.07
Node-1 100yr-4hr-Chi 0.64 1.53 79.25
Lake Ontario 5yr-4hr-Chi 0.99 0.61 76.01
Lake Ontario 100yr-4hr-Chi 0.96 0.64 76.04
Name Storm Max d/D
(depth/diameter)
Design Full
Flow cms
Max Flow
cms
Max
Velocity
m/s
Max Flow/Design
Flow (fraction)
%
trap-channel-2 5yr-4hr-Chi 1 11.42 2.985 0.6 0.262
trap-channel-2 100yr-4hr-Chi 1 11.42 3.278 0.6 0.287
trap-channel-1 5yr-4hr-Chi 1 7.25 3.105 0.96 0.429
trap-channel-1 100yr-4hr-Chi 1 7.25 3.538 0.96 0.489
sewer 5yr-4hr-Chi 0.715 2.61 2.622 2.62 1.008
sewer 100yr-4hr-Chi 0.757 2.61 2.622 2.62 1.008
overflow 5yr-4hr-Chi 0 3.32 0 0 0
overflow 100yr-4hr-Chi 0 3.32 0 0 0
ditch-to-Lake 5yr-4hr-Chi 0.725 8.64 2.978 1.36 0.345
ditch-to-Lake 100yr-4hr-Chi 0.756 8.64 3.264 1.39 0.378
ditch to lake-2 5yr-4hr-Chi 0.725 6.03 2.978 1.06 0.493
ditch to lake-2 100yr-4hr-Chi 0.756 6.03 3.264 1.09 0.541
culv 5yr-4hr-Chi 1.361 2.19 2.978 2.69 1.359
culv 100yr-4hr-Chi 1.513 2.19 3.264 2.94 1.49
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 5
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Exhibit 2 – Profile plot from MH 1 to Lake - 5year storm
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 6
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Exhibit 3 – Profile plot from MH 1 to Lake - 100year storm
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 7
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Exhibit 4 – Profile plot from MH 1 to Lake 100 year storm with 20% more flow added to MH-1
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 8
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Exhibit 5 – Profile plot from MH 1 to Lake 100 year storm with 40% more flow added to MH-1
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 9
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Exhibit 6 – Hydrology runoff at select nodes
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1 WedJun 2016
3AM 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM
Node - HW-1
Flo
w
Time
5yr-4hr-Chi[Max 0.543] 100yr-4hr-Chi[Max 1.038]
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 10
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
DISCUSSION: The discussion below is in no particular order.
1. The 4 hour 5 year and 100 year Chicago storms were run as per the City criteria.
2. The HGL is contained within the channels and culvert in 5 year & 100 year storms.
3. No modification to the culvert crossing is required.
4. As a check we looked at overland flow to ditch. The Tc from the remote to point A (Lakeshore) is calculated as follows: City Maps: Total length - 213 m – slope of land (average) = 1.2% Tc = 30 min. from airport method C calculated from % impervious as C = 0.35 x 0.7 + 0.20 = 0.45
I= 697.4 / (Tc+5)0.764 = 46 mm/hr → Q5 = 2.78 CIA = 2.78 (0.45) 46 (7.18) = 413 L/sec XPSWMM Q5 = 543 L/sec XPSWMM flows are more conservative!
5. Freeboard in table 4 (nodal results) is difference from spill crest to HGL. Spill crest is as
follows: For HW-1 0.67m above the pipe obvert CULVIN AND CULVOUT 0.30m above the road grade NODE 1 2.11m above the ditch invert NODE 2 2.37m above the ditch invert (approximate top of bank)
6. The velocity in the ditch downstream of the culvert crossing is 1.39 m/sec. This may cause erosion. Erosion control is recommended.
7. The 100 year flood line is contained within the ditch banks. See Figure 2 in appendix A.
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS 11
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
5.0 CONCLUSIONS
1) The City Ditch can accommodate the tributary area so long as flows from the 54” (1372) Ø
sewer from Avondale Court are kept to approximately 120 % of full barrel capacity.
2) The existing 1200 Ø CSP culvert crossing can accommodate the flow without overtopping the crossing.
3) Erosion control rip-rap blanket should be implemented to control erosion downstream of the culvert crossing.
4) The 100 year flood line is well below the long term stable bank for the development of 143 Bluewater Place.
143 BLUEWATER PLACE, BURLINGTON CITY DITCH HYDRAULIC ANALYSIS
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
APPENDIX A
AERIAL VIEW OF SITE
Figure 1 Overland flow to City Ditch tributary area map Figure 2 Flood line map
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Aerial view of Site and surrounding Site.
Subject Site
FILE No. 13215 -Bluewater Place-City Ditch Analysis- August 2019.docx THE ODAN/DETECH GROUP INC.
Figure 1 Overland flow to City Ditch tributary area map Figure 2 Flood line map
(Folded in envelope)
The Odan/Detech Group Inc. P: (905) 632-3811 F: (905) 632-3363
5230 SOUTH SERVICE ROAD, BURLINGTON, ONTARIO, L7L 5K2
NO
RT
H
The Odan/Detech Group Inc. P: (905) 632-3811 F: (905) 632-3363
5230 SOUTH SERVICE ROAD, BURLINGTON, ONTARIO, L7L 5K2
The Odan/Detech Group Inc. P: (905) 632-3811 F: (905) 632-3363
5230 SOUTH SERVICE ROAD, BURLINGTON, ONTARIO, L7L 5K2
NO
RT
H
The Odan/Detech Group Inc. P: (905) 632-3811 F: (905) 632-3363
5230 SOUTH SERVICE ROAD, BURLINGTON, ONTARIO, L7L 5K2