Collective Stormwater Infrastructure Project
After receiving a grant from City of Toronto's Hometown Heroes Earth Day award to install a rainwater harvesting tank and plant garden, Calstone approached Partners in Project Green's Water Stewardship Committee. Using funds from an Ontario Ministry of Environmental and Climate Change Showcasing Water Innovation grant and Partners in Project Green's Water Stewardship capital grant, the stormwater management retrofit project was scaled up by an investment from Calstone.
Case Study: Calstone Inc. Water Stewardship
A corporate leader in water stewardship for the Highland Creek watershed
Calstone, Inc. a manufacturer of steel-based furniture products located in Scarborough, has extended its commitment to sustainability by installing innovative Low Impact Development storm water management infrastructure on their property.
Before construction commenced, geotechnical reports were consulted to estimate the water table depth below the property and tests were performed to determine the asphalt pavement thickness and permeability of the underlying subsoil (3.3 mm/h). Additionally, Calstone’s expansion, improvement and maintenance plans were developed and reviewed by Grounds Covered, XCG Consultants Ltd. and the Sustainable Technologies Evaluation Program (STEP). An important lesson learned was that, although there are inherent challenges in collaborating with so many partners, the ability to provide maximum added value to a project increases when all parties remain fully engaged.
The system includes two rainwater harvesting tanks, of which one overflows into three infiltration ponds. Two of the ponds provide temporary water storage and infiltration functions while the third functions as an attractive permanent water feature. Employees and visitors are able to walk along the edge of these ponds on a permeable walkway, which leads to an infiltration trench at the back end of the building.
These stormwater management systems will set Calstone apart from other medium-sized manufacturers in the area for having a distinct, enhanced green space for employees and showing dedication to exemplary water stewardship within the Highland Creek watershed. Since stormwater infrastructure servicing this area is aging, this showcase of Low Impact Development best management practices demonstrates to the community ways that the cost of retrofitting municipal infrastructure could be avoided.
Once fully operational, the stormwater management system will be able to capture 100% of the rainwater from Calstone’s 3,900 square metre roof, which will be used to enhance employee green space, irrigate landscaped areas and for on-site stormwater infiltration. Annually, this will divert approximately 1.8 million litres of rainwater from being directly discharged to the municipal storm sewer and, thereby help to restore a more natural water cycle to Highland Creek.