Speaking at an event hosted by London Parks & Gardens Trust, LDA Design managing partner Andrew Harland said the green space would double as temporary venues are removed and large paved areas are scaled back.
The greenfield site has undergone massive clearance work. The steep river banks have also been cut back to give better visibility of water on the site.
During the talk at the View Tube venue that overlooks the Olympic park, Harland said: "The northern park is very bio-diverse and has a ecological focus and a large green space, while the south is related more to the urban retail experience and entertainment area," he explained.
The design incorporates an integrated water management system, as well as artificial fish refuges and one of the largest areas of new wet woodland ever created.
Sarah Price, who designed the planting of the 2012 gardens, said the composition was based on the achievements of the British as gardeners and the importance of gardens in bio-diversity.
Describing the four zones, she said the choice of species was influenced by the Summer Meadow in Europe and the Kniphofia and Dierama grasslands in South Africa featuring Kniphofia rooperi and Themeda and North American Callirhoe bushii and Oenothera incana.
Three levels of planting include a 30cm low foliage layer, a medium layer of genus such as Echinacea pallida and a tall layer reaching up to 2m of Silphium, Andropogon gerardii and naked stem plants that allow sunlight to penetrate.