Resources

The P46 State highway stormwater specification sets out the design and construction stormwater requirements for all state highway improvement projects, however a construction specification will still be necessary for construction requirements.

P46 focusses on performance requirements and avoids providing guidance on how to undertake the design. It includes:

• collection and conveyance
• stormwater treatment
• cross drainage
• erosion and scour protection
• existing stormwater systems

It does not cover temporary works or sub-soil drainage, and relies on other specifications for bridge waterways, landscaping, pavements, erosion and sediment control and ecology.

It is a Technical Appendix to SM031 and will complement a wider set of approved environment and urban design specifications (eg P40 Noise, P39 Highway landscape treatments).

This specification (P46) has been developed in response to the lack of a national standardised stormwater specification in New Zealand.

It is intended that this specification will form the basis in all construction contract RFPs outlining the Transport Agency’s requirements for stormwater. It is expected that it will be used as the starting point for the development of project specific requirements and will need to be adapted as appropriate to address local issues, resource consent conditions and the scope of any given project.

Publication details

Author: NZ Transport Agency, Tonkin and Taylor
Published: April 2016
Version: 1
Reference: P46
Found at: http://www.nzta.govt.nz/resources/p46-nz-transport-agency-state-highway-stormwater-specification/

Further information

Contact the Highways and Network Operations' Environmental and Urban Design team at environment@nzta.govt.nz.

Kevin Reid