Downspout Disconnection Program

The Works and Utilities Committee recommends the adoption of the following report (April1, 1999) from the Commissioner of Works and Emergency Services:

Purpose:

To describe the feasibility, costs and benefits of making downspout disconnection mandatory for all buildings in the City of Toronto.

Funding Sources, Financial Implications and Impact Statement:

None.

Recommendation:

It is recommended that the voluntary downspout disconnection program be continued in its current form, and that the need for a mandatory program and an appropriate funding mechanism be established through the Wet Weather Flow Master Plan process.

Council Reference/Background/History:

The Budget Committee, at its meeting held on December 8, 1998, in considering a report of September30, 1998, recommending that $1,640,000.00 be allocated in the 1999 Capital Budget to continue the Voluntary Downspout Disconnection Program, requested that the Commissioner of Works and Emergency Services report to the Works and Utilities Committee on the feasibility of passing a mandatory downspout disconnection by-law. It was suggested that a mandatory disconnection by-law would result in almost all downspouts being disconnected at no cost to the City as homeowners would be forced to comply at their own expense. North York was presented as an example of where this had been done in the past.

Comments and Discussion:

(1)Connection of Downspouts to Sanitary Sewers:

The Sewer Use By-laws of all the former municipalities prohibit the direct connection of downspouts to sanitary sewers. Sanitary sewers have no capacity for significant inflows of rainwater. When their capacity is exceeded, flow can backup into basements and cause significant property damage. Where direct connections of downspouts to sanitary sewers are discovered, homeowners are required to disconnect them at their own expense. In an attempt to alleviate basement flooding problems and surcharging of the sanitary sewer system, North York made a concerted effort to locate these illegal connections and have the homeowners correct the situation. It should be noted that the subject of this report does not refer to the correction of illegal connections to the sanitary sewer system.

(2)Connection of Downspouts to Combined Sewers:

The older parts of the City were originally serviced by combined sewers. Combined sewers are much larger than sanitary sewers and were designed to carry sanitary sewage in addition to stormwater inflow from downspouts and catch basins without causing basement flooding or property damage. (They cause environmental impacts in the form of Combined Sewer Overflows (CSOs), but more on that later.) However, by the 1950's and 60's, it was apparent that old combined sewers were not providing acceptable service due to increases in impervious areas which increased peak flow rates and basement flooding, which in turn resulted in increased impacts as homeowners added living space and other improvements to basement areas. Since the mid 1960's, many of the old existing combined sewers have been relieved by constructing new storm sewers in parallel. The new storm sewers picked up all of the road catch basins, but the combined sewers still had to carry all of the flow from existing building drains. In these areas, unless the downspout had been disconnected or a new building was constructed with a direct stormwater connection to the new storm sewer as noted below, the existing building drain would carry the roof runoff and foundation drainage as well as sanitary sewage to the combined sewer.

Since 1965, in the former City of Toronto, by-laws were revised to prohibit direct downspout connections to combined sewers except where there was no storm sewer available. This only applied to new construction and major renovations. There was no provision to make the by-law revisions apply retroactively to existing buildings, as it was felt that as the City rebuilt itself over the next century, all downspouts would eventually be disconnected from the combined sewer which would evolve into a sanitary sewer.

It is estimated that at least 150,000 buildings in the City are serviced by combined sewers and that 77 percent of them have one or more roof drains directly connected to the combined sewer. These buildings are located throughout most of the former Toronto, and portions of York, East York and Ward 13 in Scarborough. There are no combined sewers in Etobicoke or North York.

(3)Connection of Downspouts to Storm Sewers:

It has, until recently, been considered perfectly acceptable to connect downspouts directly to storm sewers. There are approximately 189,900 properties with downspouts directly connected to the storm sewer system throughout the City. Storm sewers are designed to carry storm runoff, including roof runoff, directly to watercourses without treatment. However, research (starting in the late 1960's) has shown that typical urban storm drainage practices are a major cause of stream degradation due to contaminants in urban runoff (from sources such as: air pollution, animal wastes, pesticides and fertilizers, emissions from vehicles, etc.) as well as excessive erosion from flash flooding. This has led to efforts to increase the amount of on-site infiltration of stormwater into the groundwater to the greatest extent practicable. New policies and regulations being developed under the Wet Weather Flow Master Plan will propose the elimination of as-of-right direct connection of downspouts to storm sewers for new development, and only allow them where it can be demonstrated that there is no practical alternative.

(4)Current Voluntary Downspout Disconnection Program:

The current program consists of an individually addressed mailing to all property owners in the targeted area describing the program and providing a response card. City staff assess each property where the owner indicates an interest, to determine which downspouts are feasible to disconnect under the City program. A sketch is prepared of the work to be carried out and the owner signs a consent form. A City contractor performs the disconnection work as shown on the sketch, at no cost to the property owner. Do-It-Yourself disconnection kits are available upon request.

A more complete description of the current program and its rationale was provided in the September 30, 1998 report to your Committee adopted at its meeting of November 4, 1998, entitled "Delivery of 1998/99 Downspout Disconnection Program".

This free downspout disconnection service is available to all Toronto property owners, however, the program target areas for mailings will be where properties are serviced by combined sewers in former Toronto, East York, York and Scarborough.

(5)Benefits of a Mandatory Downspout Disconnection By-law:

The primary objective of the Downspout Disconnection Program is to divert roof runoff from the combined sewer system which reduces the frequency of Combined Sewer Overflows (CSOs) and also provides relief to areas subject to basement flooding.

Reducing the volume of flow in both combined and storm sewer systems through on-site infiltration of roof runoff has the following additional environmental benefits:

- less burden on sewer system and treatment facilities;

- increased effectiveness of storage and treatment facilities for CSO and stormwater;

- delay and reduction in peak flow of storm runoff;

- reduced volumes of CSOs;

- a reduced risk of basement flooding;

- recharging the groundwater table; and

- reduced peak flows and flash flooding in creeks and streams.

In the former City of Toronto, the voluntary downspout disconnection program, combined with redevelopment, has resulted in the disconnection of one or more downspouts in about 20 percent of the properties (approximately 8 percent through the City's voluntary Downspout Disconnection Program 1993-1998, and the remaining through post 1965 reconstruction and other voluntary actions by property owners). The cost to the City to obtain a voluntary disconnection averages $395.00 per property. This cost includes inspection staff, administration, marketing and contract costs. There is no direct cost to the homeowner.

The 1999 Downspout Disconnection Program has been approved to be continued on the same basis with a target of 4,000 disconnections and total cost of approximately $1,600,000.00. The City's costs will be recovered through the sewer service charge, i.e., a surcharge on the water rate.

The primary advantage of a mandatory downspout disconnection program is that a much greater number of properties would be disconnected from the sewer system than is likely under a voluntary program. An independent review of the former City of Toronto program concluded that voluntary participation in the Downspout Disconnection Program would not likely exceed 16 percent even with a number of enhancements to the program.

It has also been suggested that a mandatory program would cost the City nothing because each property owner would be responsible for their own costs to comply with the new by-law. However, considering the large numbers of properties affected, this may be perceived as simply another tax. Costs to property owners would range from zero, for those already disconnected or for those where disconnection is "not feasible", to over $1,000.00 for those who have to make extensive renovations to eavestroughs or rearrange their landscaping, existing decks and patios.

(6)Some Problems with Mandatory Downspout Disconnection:

Disconnecting downspouts is not always straightforward and the following situations would have to be avoided:

-discharging storm runoff onto a neighbour's property;

-discharging storm runoff directly onto a sidewalk;

-discharging storm runoff directly onto steep slopes which would cause erosion;

-allowing water to pool or collect against a building foundation wall;

-increasing groundwater tables in the vicinity of steep slopes which could cause slope failures;

-infiltrating stormwater where groundwater is already very shallow (unless it is intended to create a wetland or pond); and

-infiltrating rainwater through contaminated soil or fill which could result in transmission of the contaminants to surrounding properties.

Finding solutions to the above situations could make it very difficult and expensive for some building owners to disconnect from the combined sewer system. A mandatory by-law would have to make provision for exemptions. The criteria for exemptions would have to be unambiguous and also include a method for determining a reasonable maximum cost per property.

The by-law would also have to be enforced equitably. This would involve an inspection of most of the buildings in the combined sewer area over some reasonable period of time.

(7)Costs of Implementation:

If the City assumed responsibility for the costs of the program, then the expenses would be spread among all those paying for water through recoveries on the water rate. Also, the City is able to obtain competitive prices by contracting for approximately 1,000 properties at a time. The average price per property has been $200.00 in the former City of Toronto. The average price would likely be reduced when neighbourhoods with larger lot sizes (and therefore simpler disconnections) are included.

There would be inspection costs to enforce the by-law and to assess feasibility at various properties. An analysis of the current program has shown that it costs approximately $50.00 to inspect a property and assess the feasibility of disconnecting its downspouts. Considering that there are more than 300,000 properties in the City with downspouts to disconnect, the inspection and enforcement costs would still be considerable.

The Wet Weather Flow Master Plan will be reviewing alternative funding mechanisms for stormwater management and there may be more directly appropriate means to recover costs for stormwater services.

(8)Legal Authority:

A legal opinion obtained by the former Borough of East York and reviewed and confirmed by City staff, states that the City has the authority to require the disconnection of existing downspouts as part of its duty to regulate and maintain the sewage system in a way that does not cause damage to the users of that system. From a legal perspective, the fact that there may have been a previous approval or even an obligation to connect downspouts to the sewer system in no way impedes Council's ability to now prohibit connection and require disconnection. However, if Council enacted such a by-law, and if there was a flood which resulted in a claim by a property owner against the City, it could be held liable in negligence if it had failed to effectively enforce the by-law. Therefore, the Council should also make a policy decision with respect to how the by-law would be enforced including provisions for staffing and phase-in.

Conclusions:

It is recommended that the voluntary downspout disconnection program be continued in its current form, and that the need for a mandatory program and an appropriate funding mechanism be addressed through the Wet Weather Flow Master Plan process.

Contact Name and Telephone Number:

John Warren, P.Eng.

Director, Environmental Services

Technical Services Division

Tel: (416) 397-4625; Fax: (416) 392-6279

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The Works and Utilities Committee reports, for the information of Council, having also had before it during consideration of the foregoing matter a communication (April 21, 1999) from Ms. Karen Buck, Toronto, Ontario, providing recommendations with respect to the Downspout Disconnection Program.