LLOYDS CROSSING This design exemplifies the remarkable notion that intense urban redevelopment does not have to be detrimental to the environment. That in fact it can reverse environmental impact and return many of the ecological qualities of the site, similar to those once offered by the 54 acre mature, mixed conifer forest to which this site was once host. Situated in Portland Oregon, the basis of this project was centered around the pre-development perameters of the site. An historical ecological profile before human presence was created. This formed the basis of the concept which was to recreate the native habitat and aim to fulfill the functions and processes of the pre-development ecosystem whilst maintaining a comfortable habitable human environment. The designers state that in such a high-density urban context such as Lloyd Crossing, it is evident that “landscape or buildings alone cannot achieve the goal of returning the ecological performance of the site to pre-development levels”. To achieve this, the design had to be based on ecological systems. A systematic strategy creating an interconnected system between habitat, water, energy and carbon use was developed. Research was carried out to explore the ecological history or the site, the pre-development habitat. The research into biodiversity and wildlife showed that there was once a mixed conifer forest with 90% tree cover and broad diversity of wildlife species. The new landscape design set out goals to increase native tree cover to 25-30%, create structurally diverse planting schemes both the ground plane and on vertical
Fig. 097 was stormwater runoff, 50% was infiltrated into the ground, 15% transpired and 5% evaporated. The plan envisioned a “water neutral” site that lives within the average annual rainfall budget that falls on site. The design would use buildings, landscapes and engineered systems to closely mimic the pre-development conditions while accommodating a five-fold increase in urban density. Solar energy and carbon cycles were also calculated to determine pre-development energy cycles. The resulting energy design goals were to exceed pre-development solar utilization conditions and reduce carbon emission to predevelopment levels. This would be achieved through a number of means such as maximizing renewable on-site energy generation, district energy and water systems, and utilization of the carbon sink potential of green spaces.
The study concluded that energy and water systems could provide a clear return-on-investment, while habitat provides intangible value. To demonstrate the benefits of investing in the whole system, the design team suggested the use of a new type of financial model, a Resource Management Association, which gave property and systems owners an ongoing source of funds for achieving water, energy, carbon and habitat goals, while also providing funds for adopting new technologies. (Hayter 2005)
Biomimetic Design for Landscape Architecture