In June 2002, First Independent Bank of Vancouver, Wash., began construction on its 15,000 square-foot First Investments Plaza office complex. The bank planned to use part of the space to relocate its banking and administrative services, and lease out most of the new complex.
Engineers from Mackay & Sposito, Vancouver, Wash., recognized that a bioinfiltration swale site took up about 2,750 square feet of buildable land. Trying to maximize available land usage and keep total costs down, they determined that replacing the swale with an underground system offered the most economical solution. It would also free up the aboveground area and treat runoff from the sites increase in pavement to gain parking.