Managing Stormwater Runoff
New Technology Provides Valuable Information For Managing Stormwater Runoff
New technology and 15 months of extensive research has given Auckland City a complete set of maps of impermeable surfaces throughout the isthmus.
The maps pinpoint the extent to which natural surfaces are covered with impenetrable materials, such as concrete. They provide an invaluable tool for the management of stormwater runoff, which is an issue of increasing concern for Auckland City.
The ground-breaking system has been developed by Greg Paterson, Manager Stormwater, who evaluated both satellite and aerial photographs with technical assistance from City Design. The aerial photographs were chosen because of better definition while advances in the GIS (Geographical Information System) enabled the analysis to be done.
Planning and Regulatory Committee chairperson Councillor Juliet Yates says the maps show the current status of every site on the isthmus and will give quick and highly coloured information as to how each site complies with the District Plan’s coverage rules for stormwater management.
“On an undeveloped site, rain is partially absorbed into the soil and nourishes trees and other vegetation,” Councillor Yates explains.
“When the soil is covered with concrete, buildings and driveways, stormwater must be collected and fed into the stormwater drains, some of which are near capacity or in need of upgrade or repair. This influences the permitted density of development.”
Councillor Yates says residents in some parts of the city fear flooding in each heavy storm.
“Now, when enquiries are made or resource consent applications are considered, the council has a reference tool which shows the percentage of impermeable surfaces on the subject site and adjacent sites,” she says.
“This should take some of the uncertainty away and be a help to residents and developers alike.”
Councillor Yates says the system may also assist councillors dealing with enquiries from constituents and planning commissioners who need to consider stormwater issues raised at hearings.
“It is an extremely important and valuable tool in terms of planning wisely for Auckland’s future needs,” she says.
further information, please contact:
Councillor Juliet Yates, tel: 528 0581 or 025 327 437.