SS Credit 6

Sustainable sites

Stormwater quantity control

PROPOSED SOPREMA SOLUTIONS:

• SOPRANATURE green roof systems: A SOPRANATURE roof outfitted with an AQUAMAT JARDIN OR PRAIRIE CAPILLARY MAT and a 150 mm SOPRAFLOR growing medium that can retain as much as 98% of rainwater for precipitations of up to 18 mm. Up to 76 to 116 L/m2 of water can be retained, depending on the culture substrate used.
• SOPRANATURE green roof systems: A SOPRANATURE TAIGA roof with a 150 mm SOPRAFLOR culture substrate, generally retains 55% of rainwater, which in real terms amounts to between 64 and 104 L/M2, depending on the growing medium used.

INTENT:

Limit disruption of natural hydrology by reducing impervious cover, increasing on-site infiltration, reducing or eliminating pollution from stormwater runoff, and eliminating contaminants.

Implement a stormwater management plan that, during the performance period, infiltrates, collects and reuses runoff or evapotranspirates runoff from at least 15% of the precipitation falling on the whole project site (including the roof area) both for an average weather year and for the two-year, 24-hour design storm.

Implement an annual inspection program of all stormwater management facilities to confirm continued performance. Maintain documentation of inspection, including identification of areas of erosion, maintenance needs and repairs. Perform all routine required maintenance, necessary repairs or stabilization within 60 days of inspection.

POTENTIAL TECHNOLOGIES AND STRATEGIES
Collect and reuse stormwater for non-potable uses such as landscape irrigation, toilet and urinal flushing and custodial uses. During facility or site alterations or additions, specify the use of alternative surfaces (e.g. vegetated roofs, pervious pavement or grid pavers) and non-structural techniques (e.g. rain gardens, vegetated swales, disconnection of imperviousness, rainwater recycling) to improve perviousness, thereby restoring or maintaining natural stormwater flows. Incorporate stormwater management facilities into routine preventive and corrective maintenance programs.

Green roofs make for better management of runoff water in urban situations. A substantial portion of the rainwater is held by the culture substrate and the plants themselves, which delays and reduces the volume and flow of runoff water into the stormwater sewer system. As some of the rainwater is trapped in the growth medium, it will eventually be used by the plants.

In conclusion for this category, note that SOPREMA can also contribute to meeting the prior condition (compulsory prerequisite in a LEED® project) whereby the purpose is to "control erosion and sediments."

There are also a few plants renowned for water filtration: phragmites, cattails and bulrushes.

THE TWO ALTERNATIVES BELOW ARE EFFECTIVE WAYS TO MANAGE WATER FLOWS DURING STORMS: