Sponge City Philosophy
The Sponge city concept has gained significant recent attention, particularly in the emerging Chinese water marketplace. It is the foundation of the new emphasis on water as a resourse and represents the first step in managing the water cycle for environmental benefits.
The ideology is that when rainwater reaches the ground it can be captured or retained and used to infiltrate the ground, thereby providing significant offset benefits in the initial stages of water resource management.
The infiltration is designed to hydrate the ground in areas where the impervious surfaces have changed the nature of the environment. Impervious surfaces can also potentially carry contaminants in the run-off into receiving water ways.
Infiltration also acts to reduce localised flooding and mitigate against erosion from water flows across catchments. This also reduces the sediment load and avoids the spread of contaminates.
The principle method of infiltration includes pervious pavements as in Low Impact Development (LID) in car parking spaces and public access space or as free draining storage that holds the water and supports various porosity rates from underground retention devices.
Other methods that are considered in project developments is rainwater harvesting in association with Water Sensitive Urban Design (WSUD) principles where larger municipal planning for housing and construction projects incorporates a broader range of rainwater resource utilisation and environmental protection measures to achieve water quality outcomes for ecological health and human amenity.
Are you practicing infiltration techniques in some form?