CLC Consulting Group Ltd successfully completed the design and construction of an all-weather overflow carpark project at the Auckland Botanic Gardens. This innovative carpark maximises space efficiency and provides year-round parking availability. As part of this development, we also redeveloped the access road to the carpark, transforming it into a more pedestrian-friendly route.

One of the highlights of this project was the distinct lack of “physical” drainage, where pipework and access chambers were kept to a minimum. Instead, the entire carpark relies on a series “green” systems including vegetated swales, which capture and convey stormwater runoff to raingardens. The swales have been planted with native grasses and plants that help filter out pollutants. The raingardens have been specifically designed to collect and absorb rainwater from the carpark and are filled with a specially designed soil mix and planted with vegetation that can tolerate both wet and dry conditions.

Benefits of a green stormwater treatment system include: natural filtration of pollutants such as sediment, oil and heavy metals, reduction of flooding by allowing runoff to infiltrate into the ground and be taken up by evapotranspiration (water uptake from trees and plants), enhanced biodiversity and aesthetic appeal.

Overall, the incorporation of swales and raingardens in the carpark project reflects CLC Consulting Group Ltd.'s commitment to sustainable and environmentally friendly design practices.