SESSION THEME | Values - landscapes, ocean and water


Porirua, a case study for how the provision of drinking water, wastewater services and stormwater management can guide or impede urban development and freshwater outcomes

Wednesday 1 April,  

In Porirua, wastewater was reticulated in the 1950s and 60s with pipes that delivered sewage directly to the city's streams and harbour. A wastewater treatment plant was only built in 1989. Today, in response to the NPS-FM the community has given voice to the value of this network in achieving clean water. They are saying that they want an improved wastewater system that doesn't pollute their water.

At the same time, significant urban development is needed to accommodate an additional 25,000 people in Porirua over the next 30 years. In addition to houses, these people will need a reliable supply of water, protection from flooding and a wastewater system that does what it's supposed to do when you flush the toilet. The value and costs of these urban services, buried under the ground in aging and forgotten pipes, are often overlooked.

The new NPS-UD has a focus on encouraging higher densities near existing infrastructure (growth up) and in greenfield areas where good infrastructure can be provided (growth out). It is often assumed that the existing infrastructure can accommodate growth up, but is this true?

An innovative "three-waters" catchment plan prepared by Wellington Water was used to assess the relative costs of providing water services for urban growth in four areas near existing services and in three greenfield areas.

The results presented can be used to provide a useful check on the true costs of growth. We will discuss the methodology used for this project and the lessons learned, which are relevant to all planners involved in urban growth planning. We will show that specific solutions addressing the challenge of meeting both the NPS-UD and the NPS-FM community outcomes can be achieved through effective catchment planning

Presenters:  Emily Greenberg & Mary O'Callahan

Land Development Planner, Wellington Water Ltd

Emily Greenberg is a planner working at the intersection of urban growth and water services. A full member of the NZPI and a background as an environmental scientist, Emily is now learning to appreciate the finer details of planning for water supply, wastewater and stormwater infrastructure.

Technical Director - Planning, GHD Ltd

Mary is a planning consultant and Principal of GHD, and an experienced RMA hearing commissioner. She works with a range of fantastic clients throughout New Zealand on a broad range of projects.  She particularly enjoys the interface between urban and infrastructure planning, as infrastructure is such a key shaper of our urban areas and communities. 


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