General informations
Description
Water Sensitive Urban Design (WSUD) is an emerging urban development paradigm aimed to minimise hydrological impacts of urban development on environment. In practice, the WSDU integrates stormwater, groundwater water supply and wastewater management to:<ul><li>protect existing natural features and ecological processes;</li><li>maintain natural hydrologic behaviour of catchments;</li><li>protect water quality of surface and ground waters;</li><li>minimise demand on the reticulated water supply system;</li><li>minimise wastewater discharges to the natural environment;</li><li>integrate water into the landscape to enhance visual, social, cultural and ecological values.</li></ul>WSUD aims for an integrated approach across various scales, from individual allotments to large subdivision and major catchments. In practice, to apply WSUD principles means to:<ul><li>protect natural creeks and other waterways on site;</li><li>reduce potable water demand through measures such as water efficient fittings and appliances, rainwater harvesting and wastewater re-use;</li><li>treat in a decentralised manner urban stormwater for re-use and/or discharge to receiving waters;</li><li>match the natural water runoff regime as closely as possible;</li><li>minimise wastewater generation and treating wastewater to a standard suitable for effluent re-use opportunities;</li><li>integrate stormwater management into the landscape, creating multiple use corridors that maximise the visual and recreational amenity of the development;</li><li>support water utility innovations.</li></ul>A comprehensive strategy for WSUD, should consider the following technical aspects: (i) planning for water conservation (optimise water distribution amongst various uses, investigate potable water conservation, wastewater re-use and storm water harvesting opportunities); (ii) improve quality of storm water (including storm water treatment measures to reduce pollutants); and (iii) integration with elements of urban design. Institutional aspects such as collaboration with watershed authorities, alternative approaches to community involvement, and ways to drive innovation are as important and should frame the whole process of WSUD implementation.Reducing hardened, impervious surfaces and accurately design drainage of urban spaces, in combination with the use of pervious roads, penetrable concrete and water passing pavements helps to enhance the infiltration of storm water in underlying surface, reducing runoff into sewerage systems and urban spaces, attenuating flood peaks, reducing the urban pollution load in run-off), as well as reduce the risk of damages due to drainage system failure by flooding. facilitating groundwater recharge. Sustainable Urban Drainage Systems (SUDS) are made up of one or more structures built to manage surface water runoff; they tend to mimic natural drainage. SUDS often incorporate soil and vegetation in structures that are usually impermeable (e.g. green rooftops); the uptake and passage through soil and vegetation reduces runoff velocity and improves water quality. Surface permeability in urban areas can be increased by using permeable paving where appropriate (e.g. footpaths, car-parking areas, access roads), thus reducing surface run-off and increasing groundwater recharge. The harvesting and use of rainwater can reduce the pressure on drinking water resources. Infiltration devices, such as “soakaways”, allow water to be drained directly into the ground; basins, ponds, and urban infrastructure such as children’s playgrounds can be designed to hold (excess) water when it rains. Measures for rainwater utilization for non-potable uses and design of urban public spaces can help meet water efficiency targets and improve environmental quality.