Stormwater's impact shapes city strategies

April 8, 2004

North Shore City is being forced to take more notice of the impacts - including the costs - of stormwater in North Shore City. This will require regulatory and organisational change.

With one of the longest coastlines for any urban authority in New Zealand - and most of that in sandy, swimmable beaches - the city has taken a lead in its endeavours to reduce the effects of both wastewater and stormwater discharges on its streams and beaches.

Reducing wastewater or sewage overflows has been top of mind for city planners, councillors and the general public for several years.

But with the realisation of the long-term damage to the environment caused by stormwater there's a growing need to align stormwater policies, objectives, strategies and spending with a new environmental imperative.

North Shore City Councillors have been wrestling with the issue of how to deal with stormwater and its effects for some time, and the issue was again discussed at this week's works and environment committee meeting.

The meeting was told a change in focus is now needed, with the emphasis on reducing stormwater run off and slowing it down, rather than putting in more pipes. The committee adopted the Stormwater Strategy 2004, which is expected to bring about major changes to the management of stormwater in the city.

Chairman of the council's works and environment committee, Joel Cayford, says the report presented to the council is a 'landmark" work, as it signals the need to manage stormwater runoff at source rather than providing more and more pipes "at the bottom of the stormwater cliff".

"With the inevitable growth in the city over the longer term, the council needs a complete change of focus from providing stormwater pipes to managing runoff. The City Blueprint sets the framework for managing the continuing growth of the city. This means more housing, more people, more runoff from roofs and driveways, and more pollution from vehicles and other sources. We therefore need to find a sustainable solution for dealing with stormwater, " he says.

"This means we must develop an integrated approach across all council departments," says Cr Cayford. "This will require organisational change. Many of the city's present flooding problems can be blamed on the fact Council's staff have unwittingly permitted developments to be built - including roading - which cause downstream flooding. This has to change."

But he warned that stormwater effects can never be eliminated completely, and the aim is to reduce the nuisance and environmental effects to acceptable levels.

Stormwater planning engineer Chris Stumbles says the council needs to implement its stormwater strategy by changing its policies and rules for stormwater management.

These policies would aim at reducing stormwater runoff, managing it better, and reducing pollutants. This is a better option than continuing to build bigger and more expensive pipe systems, he says.

Councillors heard that a new approach to stormwater management included:

-Better stormwater controls for new developments in greenfield areas
-Better stormwater controls for redevelopment in existing urban areas
-Retrofit stormwater management solutions where these result in significant and measurable benefits and in accordance with the availability of funds and a new prioritisation process.

Ends

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