What on earth is LIUDD?
Low impact urban design and development (LIUDD) looks at how development impacts on the environment, recognising that ecosystems have limitations that humans must work within to ensure sustainability.
LIUDD’s premise is to enhance the performance and competitiveness of cities by improving the integration between human activities and natural processes. Water, soil, animal and plant life provide a diverse range of services – from local climate and water regulation to recreation, amenity and mental well-being, and their health warn us when the impacts of our activities exceed safe levels. LIUDD refers to ideas, methods and practices that ensure our urban development activities utilise rather than damage or destroy natural processes.
Landcare Research and the University of Auckland led the LIUDD programme, which was funded by the Foundation for Research, Science and Technology between 2003 and 2009.
Research leader Michael Krausse says ‘low-impact’, ‘water-sensitive’, and ‘energy-efficient’ urban design and development have been rapidly evolving in New Zealand since the late 1990s and underlying these is the common goal of working with the local environment – in terms of location, topography, hydrology, soil characteristics, and biodiversity – to reduce the impact of urban development.
‘So, in the case of stormwater, this translates to exploring at design stage the potential for reducing impervious areas and site disturbance, maintaining infiltration and vegetative cover in strategic areas, and incorporating storage and reuse to manage peak flow and water quality,’ Mr Krausse says.
‘In residential redevelopment it means exploring the opportunities for increasing density close to key services, facilities and transport routes; maintaining strong links between landscape and the social context and character of the community; providing a mix of urban form and housing types to provide for a diverse community; facilitating walking access to and use of high quality public spaces; and designing energy, water-use and waste-disposal efficiencies into the infrastructure.’
LIUDD is a combined responsibility of developers, policy, planning and regulatory agencies, service providers, builders and residents for the benefit of the community as a whole. It requires collaboration by all these parties to be effective in all senses – outcome, cost, maintainability, and capacity to adapt.
It can include strategies to prevent environmental damage (development setbacks, source control of pollutants), reduce impervious surfaces (clustered housing, narrowed streets) incorporate green infrastructure (rain gardens, swales, green roofs), reduce reliance on imported services (water reuse, energy generation, waste minimisation) and protect and restore natural features (stream channels and margins, bush fragments).
The emergence of LIUDD for medium-density urban expansion and redevelopment is a recent phenomenon driven by rapid urban growth in both metropolitan and regional centres. This has created significant demand for new housing and infrastructure at a time when local government resources have been stretched by delegated responsibility from central government, the need to replace failing or overstretched first-generation infrastructure, and resistance to increased property rating.
Development of LIUDD in New Zealand has been led by local authorities (notably the Auckland Regional Council, city councils at Auckland, North Shore, Manukau, Waitakere and Christchurch, and Kapiti Coast District Council), particular developers and their consultants, industry, and researchers.
Their work is reflected in the establishment of demonstration sites; support for visits from international specialists; publication of concepts, principles, and design guidelines; development of policies and plans; and teaching content in university planning, engineering, and landscape architecture degrees.