Constructed “Source” Wetland Concepts Applied to Urban Landscapes

A class of wetland is introduced which employs engineering practices and installations to collect, store, dispose of, retrieve and use stormwater, at source, in the urban landscape. Two Adelaide (South Australia) examples of "source wetlands" are described. At New Brompton Estate, roof runoff from (eventually) a cluster of 15 residences is diverted to a 106 m gravel-filled trench in a central reserve. The collected water sustains a row of deciduous trees bordering the reserve and provides frequent (winter) charges, via a bore, to a Quaternary aquifer at depth 30 m. At Northfield a swale/trench system which handles all storm runoff from a residential street (including domestic contribution) will be trialled. Runoff seeping to the trench from the swale will be of high quality and will provide charges of water to a 5 m Quaternary aquifer. Some runoff of good quality will pass from the catchment in large storm events. In both cases, New Brompton and Northfield, water retrieved from the Quaternary aquifers in summer will be used for open space irrigation. Constructed source wetlands offer a valuable new option in urban stormwater quantity/quality management.