Rainwater management innovation in the Comox Valley: first Wal-Mart, then Home Depot
The projected growth of Vancouver Island and resulting cumulative impacts are drivers for reassessing where and how land is developed, and water is used. To promote a new way-of-thinking related to infrastructure policies and practices, Convening for Action on Vancouver Island (CAVI) organized Showcasing Green Infrastructure Innovation on Vancouver Island: The 2007 Series.
The rainwater management plans for Wal-Mart and Home Depot were featured as part of Showcasing Green Infrastructure Innovatiion in the Comox Valley in October 2007. The event was co-hosted by the Comox Strathcona Reglonal District and the City of Courtenay. The theme for the event was 'Connecting to Sustainability'.
Capturing Rain Where It Falls
Wal-Mart was the first big box store to come to the City of Courtenay. The 9.3-hectare site includes additional commercial buildings. As the site was close to 
the Millard Creek and the Comox Harbour, there was a critical need to capture rainwater/stormwater, treat it and retain it in the catchment area.
According to Kevin Lagan, Driector of Operational Services for the City of Courtenay, “The Wal-Mart development precipitated the beginning of a major change in how the City administers the zoning/development/approval process, collaborates with other agencies and also manages the rainwater resource.”
First Deep-Well Application for Rainwater Runoff Injection in BC:
The Home Depot development went beyond the Wal-Mart experience in terms of how rainwater runoff is captured and retained in the catchment area: Home Depot established a BC precedent when it implemented a deep deep-well system for injecting rainwater runoff and recharging the underlying groundwater aquifer.
The Home Depot site is located on a high point of land at the upstream end of the catchnment for Brooklyn Creek. Any drainage flows entering the creek are conveyed through the City of Courtenay, the Regional District and the Town of Comox prior to ocean discharge.
“Prior to development, the 4-hectare site was 100% forested, and therefore rainfall absorbing. The developed site is only 10% landscaped, with the other 90% now rainfall shedding,” explains Kevin Lagan, “The dramatic change in site characteristics meant rainwater runoff had to be captured to 
maintain a before development hydrologic regime, if the project was to avoid downstream impacts.”
“Through negotiations with the developer, government agencies and the use of a variety of innovative on-site rainwater/stormwater measures, we were able to achieve no rainwater runoff leaving the Home Depot property for storms occurring up to once in two years,” reports Kevin Lagan.
For more information on Showcasing Green Infrastructure Innovation in the Comox Valley, please click here.
Who is CAVI?
The CAVI Partnership comprises the British Columbia Water & Waste Association, the Real Estate Foundation of British Columbia, the provincial Ministries of Environment and Community Services, and the Green Infrastructure Partnership.
CAVI is co-funded by the Province and the Real Estate Foundation of British Columbia. The Water Sustainability Committee of the BCWWA is the managing partner and is providing program delivery. For more information about the CAVI Partnership and what it wants to do, please click here.
Posted October 2007