Flooding

The Ugliest Side of Toronto’s Ravines

Thanks to Debra Satok for following up on this article about how stormwater is ruining our ravines with City officials.  This article demonstrates just how important it is for new developments to embrace the opportunity to keep rainwater on site rather than allowing for storm sewer connections that contravene current bylaws.  In order to build sustainable communities of the future, we need to change the old traditional paradigms and embrace technologies like permeable pavers and bathtub foundations that encourage water absorption at the source.  Increasing lot coverage and dramatically reducing the amount of softscape present in neighbourhoods is counter-productive.
https://www.thestar.com/news/insight/2016/10/15/the-ugliest-side-of-torontos-ravines.html=

 

Study Area 40 – Basement Flooding & Water Quality Improvements Study

A Public Event #2 was held on July 24, 2018 to review, discuss and provide feedback on the preliminary recommended solutions for Study Area 14.  The proposed solutions include a number of storm and sanitary sewer system upgrades and water quality improvement initiatives.  A link is provided to the Study Newsletter #3 as well as 2 pages of detailed ‘mapping’ of the proposed infrastructure upgrades in the North Section (includes the SAHRA area) and the South Section.
Area 40 Basement Flooding Proposed Infrastructure Upgrades 4 pgs Jul 2018
Area 40 Basement Flooding Proposed Infrastructure Maps July 2018

Slides of the Picture Boards at the July 24, 2018 Public Meeting:
2018 PIC 2 general info boards Jul 2018

 

Update 2016

A Master Plan Class Environmental Assessment (EA) study is underway to determine the contributing factors for surface and basement flooding in Study Area 40 (which includes the SAHRA area).  The study will recommend solutions to improve the City’s sewer system and overland drainage routes in order to mitigate flooding problems.  This study will also aim to improve the quality of stormwater runoff before it is discharged to watercourses.

Study Newsletter #1 was delivered to houses within Study Area 40 (generally Highway 401 down to just above St. Clair and from Bayview over to Bathurst).  The Study was also advertised in local papers such as The Mirror on Jan 28, 2016.

Study Newsletter #1 was delivered to houses within Study Area 40 (generally Highway 401 down to just above St. Clair and from Bayview over to Bathurst).  The Study was also advertised in local papers such as The Mirror on Jan 28, 2016.

The Study Process consists of four phases – Data Collection, Identify Problem + Opportunities (expected to be completed by Fall 2016) and then Evaluate Alternative Solutions (by 2017) and then Select Preferred Solutions.

Two Public Information Centres are planned – the first to take place in late 2016.

The City asked residents to take part in a short online survey: http://tinyurl.com/qbw5uuv

Email: [email protected] 

Residents were invited to the first Public Information Centre (PIC) held on Sept 27, 2016 to learn about factors contributing to surface and basement flooding and the different options being considered to reduce flooding in Study Area 40.  They had an opportunity to review display boards and speak one-on-one with project staff.

A number of representatives from Ward 16 Residents’ Associations (SAHRA, OOGRA, LPRO, EGRA) were present at the Sept 27, 2016 Public Information Centre to learn about the different options being considered to reduce flooding in Study Area 40.  Debra Satok submitted a summary of Key Issues to the City Officials from a Ward 16 perspective:

  1. Redevelopment of Avenue Road between Wilson and Lawrence, as well as the Eglinton Corridor
  2. Uncapped Laterals
  3. 250 Lawrence Avenue West
  4. Infiltration Rates
  5. $32,000 Per Benefiting Property Threshold
  6. Downspout Disconnection

 

A summary prepared by SAHRA summarizing City information on Studies for Area 18 and 40:
A plan for Basement Flooding Protection work was approved by Council in 2006.  In accordance with the requirements of the Province of Ontario’s Environmental Assessment Act, a Class Environmental Assessment study must be completed that includes the evaluation of alternative solutions and consultation with affected stakeholders before any work can be implemented in a given area.

At that time 32 study areas were identified, each representing a sanitary sewer drainage area serviced by underground sewer networks; was updated by the City in April, 2015.

Flooding EA Map by Ward Apr 2015

 

A very detailed engineering assessment is required, typically over a two year period, to identify the most efficient and preferred solution.  The solutions are neighbourhood specific and consider local factors such as the topography of the area, sewer system design and function, drainage associated with individual lots and the road network.

Construction of storm drainage and sewer improvement works began in 2009 and will continue for years to come.  So far $32.8 million has been spent on 4.2 km of sewer upgrades benefitting 2840 properties at high risk of flooding.  Construction of a big project of retrofitting an above ground stormwater tank (at the Wastewater Treatment Plant, North York), is on hold pending the Coxwell emergency bypass completion.

Flooding Areas 18 and 40.JPG

The Area 18 study of the area from Avenue over the Bathurst/Allen started in November, 2011 is nearing completion and a project file will be released to the community in the local library for a 30 day review (the release date will be in the local paper).  The recommended solutions for Area 18 include (a) new storm sewers (b) storm sewer upgrades (c) underground storage pipes and (d) storage tank pumping.  Once the study is completed, the recommended infrastructure improvement projects are sequenced into a 5-year project list, which is presented annually to City Council, to undergo engineering design and construction.  Engineering design in Area 18 could begin as early as 2015 and this typically takes two years to complete, followed by construction.  As all projects cannot be implemented at the same time, projects are prioritized as per Council approved criteria to protect the greatest number of properties as soon as possible, within approved budgets and coordinated with other construction work.  2015 plus 2 years (design) plus 1 to 3 years of construction would call for completion between 2018 to 2020.

The City has published a final, detailed version of the A18 Recommendations including costing details ($1,484,000).

Area 18 Final Solutions

The Area 40 (the SAHRA area) study will begin in 2015 and take 2 years to complete.  A Study Report (with recommendations) would be expected to be issued in late 2016.  Public meetings will take place when the study is initiated and at various stages of the process.  The study would then follow the process outlined above for sequencing in the 5-year project list and eventually a 2 year engineering design period before construction would commence.  2017 plus 2 years (design) plus 1 to 3 years of construction would call for completion between 2020 to 2022.

In the interim, the City of Toronto is strongly advocating/advertising that it is essential that homeowners take the appropriate action to reduce the risk of basement flooding on their own private property.  They state “Those who isolate their home from the City’s sewer system can significantly reduce the risk of basement flooding.”

To assist homeowners, the City offers owners of single-family, duplex and triplex residential homes a financial subsidy of up to $3,400 per property to install flood protection devices including:

(a)   Backwater valve
(b)   Sump pump
(c)   Pipe severance and capping

 

Further information on the City’s program is available via this link:

https://www.toronto.ca/services-payments/water-environment/managing-rain-melted-snow/basement-flooding/basement-flooding-protection-subsidy-program/

 

Request for a By-law change to require permanent capping of old sewer laterals prior to Demolition

Our area suffered basement flooding in August, 1986, May, 2000, July, 2002, August, 2005 and July, 2013. As Residents’ Associations, both SAHRA and the Old Orchard Grove Residents’ Association have been concerned about defining causes and finding solutions to prevent future occurrences. Debra Satok has done extensive research on this issue and a potential source of flooding are uncapped sewer laterals.

When a home/building in Toronto is demolished, the existing sanitary and storm sewer laterals (the pipes leading to the main street sewer) are disconnected and simply left open during the remainder of the demolition and subsequent construction.  When the new building is close to completion and ready for the connection of the new sanitary and storm sewers, contractors are hired by the city to install new sanitary and storm sewer laterals, as well as find, and permanently cap, the old ones.  Often contractors are unable to locate the old sewer laterals so they remain open; permanently uncapped.

Uncapped sanitary and storm laterals allow ground water to enter the sewer system, putting additional strain on the sewer shed, overwhelming the treatment plants and costing tax-payers for unnecessary water treatment.  It also leads to basement flooding as the sewer system was not designed to handle this volume of the excessive infiltration.  Even more alarming, during heavy rains, when the sanitary sewers surcharges, sewer wastewater can flood out through the openings of the uncapped sanitary laterals sending overflowing sanitary sewage under our homes. Weeping tile systems will collect this contaminated wastewater, and sump pumps will discharge it to the homes’ lawn.

Many, if not most other municipalities have by-laws requiring capping of the laterals prior to demolition. The Canadian Common Ground Alliance recommends capping of the laterals as part of their “best practices”.The current Municipal Code 681-11-C currently states: that “The owner or owner’s agent shall apply to the City for a new municipal sewer connection or installations and, where necessary, for the disconnection of the existing municipal sewer connections, and pay to the City the cost of such work on an actual cost basis with a minimum charge equal to the applicable flat rate for such works, as determined by the City from time to time, where there is… (2) A construction of a new or reconstructed building”. The By-law does not indicate any requirements for capping prior to demolition. The current disconnection fee charged to homeowners /builders is $1300.00.

It is recommend that Toronto put in place a policy similar to Port Colborne, Ontario and Delta, B.C. whereby demolition permits are only granted once a signed declaration of severance from the various services has been received ).

FoNTRA , SAHRA, OOGRA and LPRO are in support of this initiative. While this is a city-wide issue, we have asked Councillor Carmichael-Greb to champion it and table a motion at the September meeting of the Planning and Growth Management Committee and/or the Public Works and Infrastructure Committee to ask the Staff to do a review to determine if and when the current Municipal Code 681-11 could be modified to define that demolition permits are only granted once a declaration of severance from various services has been received; asking that a Staff Report be presented to the committee(s) on their findings by Quarter 4 of 2016; followed by presentation to City Council for formal approval.

SAHRA supporting request letter July 4, 2016:  SAHRA request re Capping old sewer laterals

 

The Public Works and Infrastructure Committee published a Report on Feb 8, 2018 on their review of the City’s policy and program for disconnecting sewer service connections in respect to the timing of these disconnections and single-family residential building demolitions. The report was prepared in consultation with Toronto Building. They concluded that the current program effectively limits potential infiltration contributions and recommended that a change in policy NOT be made as it would add operational costs to the program, increase costs to property owners, and would not result in a discernible reduction in inflow and infiltration. They did state that the review has led to improved efficiencies between Toronto Water and Toronto Building as better coordination measures are being added to the program for single-family residential properties. Staff will now explore opportunities to increase coordination for industrial, commercial, institutional and multi-residential properties.
Staff Report re Capping Laterals PWIB Feb 27 2018

 

Debra Satok submitted a response on Feb 23, 2018 asking Toronto Water to report back on 5 issues.  SAHRA submitted a supporting letter to the City.
Capping of Laterals-response Feb. 23_18

 

  1. What is the total cost of infiltration annually to the city of Toronto? In 2007 it was reported as $1.8 billion.
  2. Assuming that at a minimum 5% of laterals do not ever get capped as stated in this report, what is the cost annually of this infiltration to the city of Toronto and what is the cumulative impact?
  3. Since Toronto Water cannot account for an additional 16% of abandoned laterals per year as outlined below, what would the cost of 21% of all laterals permanently remaining open after demolition be annually to the city of Toronto?
  4. What is the cost to the city of Toronto of uncapped abandoned laterals from demolition of buildings for redevelopment of industrial, commercial, institutional and multi-residential properties?
  5. What would the cost be to have an independent consultant review the current process for capping laterals and the alternatives and provide a report to council?

As the stated Best Practice of the Canadian Common Ground Alliance is that disconnects have to be confirmed prior to issuance of a demolition permit, we do not understand why the City of Toronto would NOT choose to adopt this Best Practice.

We are awaiting a response to the request that this issue be further investigated…

 

The Downspout Disconnection Program

Here is a link to City information on the program.

https://www.toronto.ca/services-payments/water-environment/managing-rain-melted-snow/basement-flooding/mandatory-downspout-disconnection/

 

Flooding

(Thanks to D. Satok for her research which we have used in this article)

Recurring basement flooding has plagued Toronto over the last two decades. The problem has intensified due to changing weather patterns, infill construction, an aging sewer system and more elaborately finished basements.

Flooding can occur from seepage or flow through the basement walls or foundation floor, from surface water sources like driveways, or by a Sanitary or Storm Sewer backup. Basements are the lowest level of a building, typically built below ground level. During spring melts and heavy rainstorms, the groundwater level can be above the level of the basement floor. In some locations where the water table is particularly high, groundwater can be above the level of the floor at all times. Sewers are also located in the ground. This includes all varieties – Storm, Sanitary and combined. While in most cases, sewers are below the level of the basement, the water level in the sewers can be, at times, above the level of the basement floor.

Gravity does its best to move water from high to low as it follows the path of least resistance. If either the groundwater level or sewer level around a home is above the basement floor, gravity will try to move that water into the basement.  A crack in the foundation floor, for example, provides gravity with a perfect path for water to be pushed into the basement. There are many reasons a basement can flood including sewer backup, seepage, weeping tile failure, sump pump failure and reverse driveway infiltration.

 

flooding

Sanitary Sewers always have a path to the home, by design, and it is called the Sanitary Sewer lateral. While under normal conditions, the lateral allows wastewater to flow away from a home to the sewer; there is the potential for water to move backwards from the sewer toward an individual home. During heavy storms, infiltration of ground water can cause the Sanitary Sewers to be full and the sewage level may rise above the top of the pipe and above that of some basements. When this occurs, the wastewater may enter basements through basement floor drains, sinks and toilets. Sanitary Sewers were not designed for excessive groundwater, as they are usually at least half the diameter of Storm Sewers. However, during heavy rains groundwater can come from leaks in sewer-mains and sewer laterals, inflow from manhole covers as well as illegally-connected, private-side sources including foundation drains, sump pumps and downspouts.

Following severe flooding in August 2005, The City of Toronto engaged the services of Stantec Consultants to evaluate the causes and make recommendations for basement flooding in 34 areas of Toronto that have been subject to chronic flooding. The Study of Area 18 (Highway 401 to Lawrence Avenue, Avenue Road to the Allen Expressway) was completed in 2014. The estimated cost of implementation for this area is $107.8 million dollars.

On July 8, 2013, severe thunderstorms and heavy rains flooded many parts of the City.  More than 4,700 basement flooding complaints were received by the City.  Many of the impacted properties were located outside of the existing Basement Flooding Protection Program’s 34 priority study areas resulting in the need to reconsider how basement flooding risks are assessed and addressed city wide. In Oct, 2013, the City expanded the program to include 7 additional areas to be assessed starting in 2014 and 2015.

The Environmental Assessment (EA) for Area 40, which encompasses the SAHRA area, should begin in 2015.

The EA will take 2 years to complete…the result of this phase is a Study Report (with recommendations) in late 2016.  Public meetings will then take place. The study would then be sequenced in the 5 year project list for the next step which is a 2 year engineering design period before construction would commence.  2017 (if slotted in the project list) plus 2 years (design) plus 1 to 3 years of construction would call for completion between 2020 to 2022.

In the interim, the City of Toronto has implemented a number of programs designed to protect homeowners and limit damage. A Downspout Disconnection initiative has been in place for several years. It is being implemented across the city in three phases….the SAHRA area was within Phase 3 which had a deadline date of December 3, 2016.  However, the sooner homes are disconnected from the sewer system, the less strain on the system and therefore less flooding.  Stantec estimates that this type of source control would cause a 10% reduction in annual volume.  The City of Toronto website includes information on the Benefits, Frequently Asked Questions, Do-It-Yourself Instructions, Tips as well as the Exemption Application process.

https://www.toronto.ca/services-payments/water-environment/managing-rain-melted-snow/basement-flooding/mandatory-downspout-disconnection/

Further information on by-laws within Toronto’s Municipal Code, Chapter 681 is contained in the following document:

Downspouts By-law Information

Rebates of up $3400 per household for a portion of the cost of installation of sump pumps, back flow valves and downspout disconnections are available. Awareness programs designed to educate homeowners regarding grading and home maintenance are also in place. Some Bylaw and Building Code changes have been executed in an attempt to design more weatherproof homes that are less taxing on the current infrastructure.  See information on the Rebate Program in an article below.

Though programs like these are positive, without change it is apparent that the aging and now inadequate design of Toronto’s sewer system will continue to place many homes in harms way each and every time it rains. It is clear that infrastructure upgrades and redesign are imperative to prevent flooding.

Typical Causes of Basement Flooding diagram:

Basement Flooding Typical Causes diagram

 

Basement Flooding Protection Subsidy Program, City of Toronto 

https://www.toronto.ca/services-payments/water-environment/managing-rain-melted-snow/basement-flooding/basement-flooding-protection-subsidy-program/

This link provides information on How to help protect yourself against basement flooding. Topics include:

* Work that is eligible
* A: Backwater valve
* B: Sump pump
* C: Backwater valve + sump pumpand maintained to ensure optimal performance.
* D: Pipe severance and capping
* Eligibility requirements and information
* How to apply for a subsidy

 

Melting Snow and Rain can lead to Basement Flooding

Extracted from the City of Toronto website

The combination of melting snow and rain can lead to basement flooding.  Here are some tips to help:

  • Keep melting snow and ice away from your foundation walls
  • Ensure your downspouts are not blocked and are draining properly, away from your foundation walls.
  • If it is safe to do so, clear debris from roadside catchbasins (the square sewer grates on the road) to help water enter the storm sewer.
  • If you are worried about an immediate threat of basement flooding, prepare your basement by moving valuables to shelves or upper floors. Cleaners, paint or chemicals should also be taken off the floor so that they do not further contaminate any floodwater that may get into your home.
  • If your basement has flooded:
    • Call your insurance company as soon as possible to report property damage caused by flooding.
    • Do not enter a flooded basement as you may be exposed to sewage or come in contact with water and electricity.
    • Be mindful of your health and safety when cleaning up a flooded basement – do not stand in flood water, call a professional for assistance.
    • Call 311 immediately to report basement flooding. During extreme weather call volumes will be high. Calls will be answered by the first available agent. 311 is open 24 hours a day, seven days a week.
  • The recent fluctuating temperatures can lead to an increase in watermain breaks. They cause the soil to freeze and expand, leading to additional force on the watermains. If you spot a watermain break, call 311 to report it.

Ongoing temperature fluctuations throughout the winter can also lead to frozen pipes.  If you suspect you have frozen pipes, call a plumber.

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