Two common redevelopment scenarios are infill redevelopment, which increases the density within existing urban areas (refer to Figure 21), and adaptive re-use developments which modify existing buildings and infrastructure for contemporary use.
Redevelopment utilises existing resources to reduce pressures on local infrastructure and direct development away from the region's hinterland. Redevelopment is also a means to create an enhanced environment for an existing site.
Recent public policy has called for increased affordable housing, higher density around public transport hubs, and the reinvention of areas such as ports of Auckland as a post-industrial waterfront. Redevelopment has also been driven by increased environmental standards relating to stormwater discharges, climate change and pollution prevention for existing activities.
The redevelopment of urban sites provides an additional set of challenges when compared to greenfield sites due to existing services and historic land uses. However, the principles of WSD and the design phases recommended here apply equally to brownfield and greenfield sites. WSD principles are presented below, with specific regard to brownfield redevelopment scenarios.
Promote inter-disciplinary planning and design. Analyse the site for mixed use development opportunities, and the potential retrofit of environmental services. It is important to consider existing community stakeholders to ensure their concerns are adequately addressed and project viability is not compromised.
Protect and enhance the value and function of natural ecosystems. Redevelopment provides the opportunity to redress existing effects of stormwater on the receiving environment, including groundwater from contaminated soils. The integration of 'green' and 'blue' infrastructure into a developed site provides increased opportunities for urban ecology and its associated ecosystem services.
Address stormwater effects as close to source as possible. The redevelopment of a site may include retrofit of pervious paving and landscape areas, relocating buildings to allow shared infrastructure, or increasing the number of floors within the existing building footprint. It is important that opportunities for prevention as well as mitigation of stormwater are considered during the design process, including use of rain water, opportunities for infiltration, and below-ground detention technologies.
Mimic natural systems and processes for stormwater management. The retrofit of a developed site does not preclude green infrastructure since living roofs, planter boxes and tree pits can all be incorporated into architecture or paved areas. The reconstruction of the site can also allow stormwater to be redirected to these treatments. The retrofit of multiple sites may also provide opportunities for centralised natural systems such as vegetated overland flow paths along boundaries and streets, or bioretention in shared open spaces.