WSD promotes the public use of open spaces associated with streams and wetlands, which can lead to increased public awareness for the values of these systems.
When designing for public use, it is important to balance public safety with the benefits of fully experiencing these environments.
Crime prevention
Designers of stormwater management areas that provide for public access require a working knowledge of the Ministry of Justice's (MoJ) guidelines for crime prevention through environmental design (CPTED). The guidelines include the following principles (MoJ, 2005):
- Access – unencumbered access and movement choices to avoid potential criminal activity
- Surveillance and sight lines – appropriate planting and access layout for clear visibility
- Layout – clear and logical orientation within a site
- Activity mix – 'eyes on the street' through encouraging access and use of a site
- Sense of ownership – a level of amenity that suggests and promotes community care
- Quality environments – well designed and maintained open spaces and stormwater facilities
- Physical protection – to encourage active use of appropriate areas only.
Community 'ownership' and vigilance can be encouraged through dedicated public access, community gathering areas, and through creating passive surveillance from adjacent homes. A community can also be consulted when stormwater management areas are being designed, and/or be invited to participate in the implementation of those designs through planting days, etc.
Injury prevention
Injury prevention through environmental design (IPTED) is informed by universal design, which promotes the safe and dignified use of public space. Injury prevention minimises risk and provides clear and safe access for the public, including through riparian reserves and stormwater management areas. Injury prevention is also important for maintenance staff to safely undertake their operational tasks, which are sometimes performed during storm events.
Perceived risk of natural outdoor areas should be balanced with the ultimate benefits of these environments to public health through the treatment of air and water quality, moderation of dust, noise and light pollution, and the psychological benefits of natural refuges in urban settings.
Stormwater management should also consider the building consent process, with adherence to codes of practice, consideration of the stability of foundations and subsoils, and provision for access and egress as appropriate. The Health and Safety in Employment Act (HSE, 1992) is also relevant for operation and maintenance. Potential areas of IPTED responsibility for stormwater management include:
- Vehicle sight lines and general visibility of landscape and stormwater management features in streetscapes, including kerb-less carriageways, etc.
- Freedom of access for wheelchairs and prams
- Potential falling hazards and obstructions
- Change in surface levels and materials beside accessways
- Opportunities for the visually impaired to access or transect stormwater management features and natural areas, while avoiding areas that may entrap or endanger them
- Providing tactile surfaces and continuous edges to assist the visually impaired with wayfinding
- Direction on potential safety issues, especially for the awareness of parents and children
- Maintenance programme to prevent any impediments to public access
- Limbing of trees and plants that may cause harm beside accessways
- Material selection to minimise harmfulness (toxicity, sharpness, slipperiness, etc.)
- Steep slopes should be broken by slope breaks or vegetation
- Prevention from entering surface ponds and wetlands where contact recreation is not promoted, but also assisting exit form these areas (through shallow sides or benches) if entered
- Lighting of accessible reserves as appropriate.