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When Toronto’s builders construct towers or large complexes, they must meet parking minimums and work with mandates to hide unsightly parking structures. Thus, they are often forced to build below-grade parking. A five or six-storey underground parking garage may experience a great deal of hydrostatic pressure and builders need a way to deal with the water.

That became more difficult after Toronto Water discovered far more water was entering their sewer systems than anticipated, and in 2013, the city began an investigation. Recommendations on how to divert as much water as possible away from the storm and sewer systems resulted in tough new amendments to the Sewer Bylaws (Municipal Code Chapter 681) which were passed by Toronto City Council in 2016.

Toronto’s builders were now faced with greater construction costs, regulations and potential delays as a result.

Impact of New Bylaws for Toronto Builders

The most significant amendment to the bylaw concerned the definition of “private water”, that being, “stormwater and/or groundwater collected on private lands” requiring discharge into a city sewer. This meant any water coming from a building, whether groundwater, rain, sewer water, or any other source, would have to be metered. Additionally, a discharge agreement between builders and Toronto Water had to be signed to guarantee either water discharge to storm drains met strict purity requirements and/or builders and building owners would pay for proper disposal through the sanitary sewage systems.

Builders and representative organizations such as Residential Construction Council of Ontario (RESCON) objected, but the city council largely ignored protests. The number of new discharge agreements rose from 263 short and long-term water discharge agreements in 2016 up to 429 in 2018; a 63 per cent increase. The city collected $6.5 million in private meter water dumping in 2018. Perhaps a minuscule amount when compared with Toronto Water’s billion-dollar budget, but a significant cost to Toronto’s builders, especially if they are compounded by additional construction delays.

Short- and Long-Term Private Water Discharge Approval

The city issues Short-Term Private Water Discharge Approval Permit for site remediation and construction dewatering completed in a year or less. Discharge fees cannot exceed $20,000. A Long-Term Private Water Discharge Approval Agreement is employed for long-term discharge activities over a building’s lifetime, or if the discharge fee is in excess of $20,000. Agreements are granted for terms of up to one year and may be renewable.

Before the revised Bylaws took effect, builders would simply apply for a short-term construction dewatering permit, then later apply for a long-term permit for continuous discharge after the building was completed. Now they must apply for both at the same time, and a great deal more information is required in the formal application. The city recommends that applications be submitted eight to 12 weeks in advance of project initiation and will not accept partial applications. Errors or omissions can derail an application, while minor ones can significantly delay construction. Getting the application right is essential.

Three Long-Term Solutions Builders Can Employ

While simultaneously applying for the short-term Private Water Discharge Approval permit needed for construction dewatering, Toronto’s builders have three long-term solutions to choose from:

  • Pay to discharge water to the sanitary sewer.
  • Create a permanent treatment system and discharge to the storm sewer for free.
  • Fully waterproof the building.

Discharging to the Sanitary Sewer

The first option often involves installing a drainage layer into the bottom of the building and using a sump to pump the water into either the storm sewer system or the sanitary sewer system. Initially, the rate for discharging private water to the sanitary sewer was $2.065 per cubic metre, but costs continue to increase. In 2019, City Council approved a rise in the water charge to $2.254 per cubic metre.

In the Old City where storm water and sanitary sewage systems are combined, there is the added problem that surface runoff and sanitary wastewater share pipes and cannot be separated. When it rains, millions of litres of stormwater end up taking capacity away from the sanitation system and a stew of human waste, rainwater and groundwater dumps into creeks and Lake Ontario. City Council may not accept more water in the sanitary systems in order to preserve capacity.

Storm Discharge Agreement

The second option, if capacity exists downstream, is to discharge private water to the storm sewer system. Up until 2016, it was common to create drainage systems that would direct all that water into tanks or cisterns that would often empty into storm sewers. Now, builders must design a water treatment system that will bring water to the quality standards set by the sewers bylaw and enter into a Storm Discharge Agreement with Toronto Water.

These water treatment facilities are costly to set up, costly to run and the city will inspect the water standards indefinitely. The application requires full mechanical and civil drawings of the permanent private discharge system before any work begins. If the system fails, the permit can be pulled, forcing a building to dispose of its onsite water through alternative methods such as trucking water to an off-site treatment facility.

Full Waterproofing

A third option is to avoid private water discharge fees entirely by designing high-rise buildings in “bathtub” style, making them fully waterproof, deflecting water away from the foundation.

“The discharge fee was built to entice builders to stop discharging their water into the sanitary sewer system,” notes Patrick Shanks, Kryton’s Territory Manager for Eastern Canada. “The cost of installing a permanent waterproofing system will be less expensive than paying the discharge fee.”

Indeed, the city has been urging builders to consider this option to prevent extra groundwater from being collected or flushed down the sewers.

But how can builders provide any assurances to the city for the watertight performance of their buildings into the future? Few, if any, waterproofing solutions on the market can assure, much less warranty, the waterproofing of below-grade structures under high hydrostatic pressure.

Kryton can.

KIM® and Krystol Waterstop System

Kryton’s Krystol Internal Membrane™ (KIM®) lowers concrete’s permeability to permanently stop water. It is a concrete admixture to be used in place of surface applied membranes. When any new moisture invades the concrete, Krystol reacts with water and un-hydrated cement particles to form insoluble needle-shaped crystals to block pores and form permanent waterproof barriers for the lifespan of the concrete. KIM® carries a “lifetime” product warranty of 25 years. Many KIM® projects have outlived their 25-year warranty!

Krystol Waterstop System also utilizes Krystol to provide a permanent waterproof solution at construction joints and adapts to curves and uneven surface.

Krystol Assurance Program

The Krystol Assurance Program allows builders taking advantage of the program to eliminate the significant risk of leaks and repairs. That’s because Kryton will repair any leaks through the waterproofing system, as well as cover costs of both materials and labor, during the next 10 years. That’s the kind of peace-of-mind Toronto’s builders may be looking for.


When builders assess the costs of all three alternatives for dealing with private water, the third option – fully waterproofing or “bathtubbing” concrete foundations and structures such as below-grade parking garages can be a viable option with the right waterproofing product.

See Most Vulnerable Concrete Details of Parking Garages to Keep Watertight










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