Stormwater Problem? New Technology Helps Mitigate Floods

Heavy Rain Hits Across Canada

Toronto flood of August 2018

Credit: Shlomi Amiga

Two days of rain in Toronto in August 2018 caused great damage and more than $80 million in insurance claims.  Since 2017, Ottawa, Gatineau, and Montréal have flooded three years in a row. A state of emergency was declared, and the army deployed in April 2019. In 2013, in just 48 hours, the Calgary area was deluged with 325 mm (13 inches) of rain – the city’s entire annual average – causing five deaths, displacing more than 100,000 people and costing $1.7 billion.  The implementation of green infrastructure and innovative technology can help the mitigate such flooding in the urban core.

Innovative Technology Mimics Nature

StormCap™+Detention is an innovative rooftop stormwater detention tool that mimics watersheds and aquifers to help mitigate urban flooding.  Detention technology allows the green roof to face second day and extra-large storms.


Superior Components

The engineered base layers include Urbanscape’s needled mineral hydro blanket, made solely of virgin rock fibre. This mineral wool has no binders and therefore has superior retention of 90% of water by volume and withstands freeze/thaw cycles.

Key Features

  • Can manage large and repeat storms and is not dependent on weather to provide a repeat performance
  • Lessen the strain on storm sewers and decrease combined sewer overflow (CSO)
  • Stores water temporarily and limits the rate at which water flows from the roof drain; and
  • Can recharge in as little as a few hours

Return on Investment (ROI)

StormCap™+Detention provides a clear ROI by reducing or eliminating cisterns and bioretention facilities and freeing up valuable space for income-generating development. It even works on a sloped roof!

Powered by Urbanscape™

The engineered base layers include Urbanscape™’s needled mineral hydro blanket, made solely of virgin rock fibre by Knauf Insulation. This mineral wool has no binders and therefore has superior retention of 90% of water by volume and withstands freeze/thaw cycles.

Most of StormCap™+Detention’s base layers come in rolls that are easy to transport and install. It is a fully customizable system with biodiversity options.  And, can be cut in any shape or size to create logos or icons on the roof!

Construction Canada cover features image of green roof in urban coreRead Construction Canada Article

Creating Friction in Green Roofs: Reinventing the Traditional Green Roof by Sasha Aguilera and Brad Garner, Construction Canada, October 2019.



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Next Level Stormwater Management logo in bold blue with logo above in blue and greenNLSM has supplied more than 2.5 M SQFT coast to coast

NLSM is Canada’s leading supplier of pre-vegetated roofs such as LiteN’Less™, Xeroflor® and StormCap™ systems. We customize to local requirements. Offer warranty& maintenance support, provide ​stormwater calculations specific to location ​and building/roof type, stormwater test data & related innovative hydrologic modeling. Email or call (416) 637-5772 Ext 1.