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1. Welcome
Investigation of Flooding in Area 2
(Leaside Area)
Public Information Centre #2
View displays and discuss the study with project staff
Feel free to ask questions and fill out a comment sheet
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2. Purpose of Tonight’s Meeting
• Overview of problems in the study area
• Outline the factors contributing to basement
and surface flooding
• Present the options considered
• Present the recommended solutions
• Outline the next steps
• Hear from you! Your input is very important
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3. Purpose of Our Study and Study Area
• Investigation includes:
 Examine existing
stormwater drainage,
combined and sanitary
sewer systems and identify
the causes of basement
flooding and/or surface
flooding in Area 2; and,
 Make recommendations to
reduce the risk of future
flooding in Area 2.
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4. Sewer Infrastructure
• Area 2 is serviced by a
combination of sanitary,
combined and storm sewers.
Combined
Sewer System
Separated
Sewer System 4

5. Our Basement Flooding Findings
Under normal rainfall events, the storm,
sanitary and combined sewer systems operate
as designed. However, during extreme storms,
the following takes place:
•Stormwater flows exceeds the capacity of the storm
and combined sewers and overloads the system.
•Water remains on the surface and flows along roads
and creeks.
•Water can enter the basements from the surface via
doors, window wells and reverse-slope driveways.
•At low lying areas, water accumulates (ponds) on the
surface and streets and enters the sanitary sewer
system through manhole covers. This causes the
sanitary sewers to surcharge and potentially backup into
basements.
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6. Our Basement Flooding Findings
(Cont’d)
• Excess stormwater can enter the sanitary sewer
system during extreme events.
• The ground and soils can become saturated with water
that can enter the sanitary sewer system through cracks,
holes or damaged joints in pipes and maintenance holes
located underground.
• In low lying areas, water accumulates (ponds) on the
surface and can enter the sanitary sewer system
through manhole covers.
• There are some homes with downspouts and/or
foundation drain connections to the sanitary sewer
system. These are direct connections and allow
stormwater to enter the sanitary sewer system.
• If stormwater enters basements through doors, window
wells or reverse slope driveway drains, it often enters
the basement floor drain which is connected to the
sanitary sewer system.
• Once the sanitary sewer system is surcharged,
there is a risk of backup into basements.
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7. Causes of Basement Flooding
(Separated System)
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8. Causes of Basement Flooding
Note: typical connections
shown, however private
drainage systems can be
more complex and each one is
unique.
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9. Options Considered for Reducing
Flooding
Source control measures involve
managing stormwater where it
originates (roofs, roads,
driveways), before it enters the
City’s sewer systems.
These measures
include:
Downspout disconnection
Rain barrels
Catchbasin inlet controls
Surface flow path diversion
Bioretention units
Sanitary sewer rehabilitation
Source Controls Conveyance Controls
These measures include:
Alternate road cross-sections (grassed
ditches / swales)
Bioretention units and bioswales
Overland flow control
Sewer pipe diversion, replacement or
twinning
Sewer separation in combined sewer areas
End-of-Pipe Controls
These measures include:
Surface dry ponds
Surface wet ponds
Underground storage tanks or underground
storage pipes
Conveyance control measures
help to control stormwater as it
travels along the drainage
system (in pipes or along the
road).
End-of-pipe control measures
control stormwater and CSOs
just before it is discharged to a
watercourse (stream, river, or
lake).
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10. Evaluation of Options
Natural Environment
• Potential Impact on Terrestrial Systems
(Vegetation, Trees, Wildlife)
• Potential Impact on Aquatic Systems
(Aquatic Life and Vegetation, Surface
Water, Groundwater)
• Soil and Geology
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Social Environment
• Effect on Urban Greenspace
(Parks, Ravines, Open Spaces)
• Disruption to Existing Community
During Construction (Traffic, Noise)
• Disruption to Existing Community
Post Construction (Visual Impact,
Odour, Safety)
• Archaeology, Heritage Resources
and First Nations
Technical Considerations
• Feasibility of Control Measure (Available
Space, Accessibility, Constructability)
• Effectiveness in controlling basement and/or
surface flooding
• Impact on Upstream and Downstream
Infrastructure
• Operations & Maintenance Requirements
Cost Considerations
• Capital Costs
• Operating & maintenance costs
Economic
The following criteria were used to evaluate options and identify the
recommended solutions:

11. Recommended Solutions
Install catchbasin inlet control
devices at identified locations
Increase the number of
catchbasins in low lying areas
Roof leader disconnection to limit
stormwater entering the sanitary or
storm sewer system
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12. Recommended Solutions
• Replace existing storm and/or sanitary sewers with larger
diameter sewers at various locations where required to
provide additional conveyance capacity in the sewer
system.
What Does it Involve?
• Road excavation within the City’s Right-of-Way
• Removal of old sewer and structures (manholes & catchbasins)
and disconnection of sewer service line(s)
• Placement of new sewer, reconnection of sewer service line(s)
• Some tree removals and replacement (after construction is
completed) may be required
• Restoration of road upon completion of construction.
Storm and/or Sanitary Sewer Replacement
and Upgrades
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13. Recommended Solutions
• Construct new storm sewers at various locations to
separate combined sewers and provide additional
conveyance capacity in the sewer system.
What Does it Involve?
• Road excavation within the City’s Right-of-Way
• Placement of new storm sewer(s)
• Disconnection and reconnection of existing sewer service lines
(if necessary)
• Some tree removals and replacement (after construction is
completed) may be required
• Restoration of road upon completion of construction.
New Storm Sewers for Sewer Separation
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14. Recommended Solutions
• Replace a portion of an existing sewer with a larger
‘superpipe’ to provide temporary storage of wet weather
flow. Once sewer capacity is available, the ‘superpipe’ is
drained by gravity.
What Does it Involve?
• Road excavation within the City’s Right-of-Way
• Potential removal of old sewer and structures (manholes &
catchbasins) and disconnection of sewer service line(s)
• Placement of new sewer and potential reconnection of sewer
service line(s)
• Some tree removals and replacement (after construction is
completed) may be required
• Restoration of road upon completion of construction.
Underground In-Line Storage
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15. Area 2 – Recommended Infrastructure
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16. Area 2 - Summary of Recommended
Infrastructure
• Recommended infrastructure needed to provide basement flooding protection
includes:
– New storm sewers to complete sewer separation on Craig, Bessborough, Donlea,
Rumsey, Hanna, Vanderhoof, Flemming, Cameron, Astor, Sutherland, Markham and
Esandar.
– New storm sewers to provide additional capacity on McRae, Burnham, Heath,
Bennington Heights, Moorehill, Mallory, Rykert, and Broadway.
– New in-line storage storm sewers to store excess wet weather flow on Southlea,
Bessborough, Moore and Pottery.
– Additional catchbasins or catchbasin inlet controls on Millwood, Vanderhoof, Laird,
Commercial.
– New in-line storage sanitary sewer on Bennington Heights to store excess wet weather
flow.
– New sanitary sewers to provide additional capacity on Burnham, Lumley and Heath.
– Inflow/ infiltration investigation for Copeland Area to identify sources of infiltration and
inflow into the sanitary sewer system.
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17. Next Steps
Anticipated
Timeline
What Will Happen?
After
Tonight’s
Meeting
After tonight’s meeting, the Study Team will review and consider your comments
to finalize the preferred solution for Area 2.
Late 2014
A Notice of Study Completion will be issued and a Project File Report will be
placed in local libraries for a 30 day public review period.
After
Completion of
the
Environmental
Assessment
Process
Implementation of the Recommended Projects – inclusion of the recommended
projects in the City’s 5 Year Basement Flooding Protection Project List.
Implementation timing will depend on:
• Sequencing of projects from completed basement flooding EA studies, as
per City Council approved criteria.
• Coordination with other planned infrastructure projects (e.g. Transportation
and utilities projects) in the area as per the City’s Multi-Year Capital
Coordination Plan.
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18. Thank You for Attending
We welcome your feedback. Please fill out the comment sheet provided.
Following this PIC, the study team will review and consider your comments in
the final selection of the preferred alternatives.
Contact Information
For more information on this study, or to provide your comments or be placed on the
project mailing list, please contact:
Josie Franch, Public Consultation Unit
55 John Street, Metro Hall, 19th Floor, Toronto, ON M5V 3C6
Phone: 416-338-2859, E-mail : jfranch@toronto.ca
Fax: 416-392-2974, TTY: 416-338-0889
Website: http://www.toronto.ca/involved/projects/basement_flooding/sa_2.htm
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