Stormwater treatment falls short

17:00, May 12 2014
Chris Darby
ROAD RAGE: Chris Darby says Auckland roads, which comprise 38 per cent of our urban environment, are the biggest run-off polluters.

Efforts to stop runoff and sewage polluting our streams and beaches on the North Shore is patchy, a politician says.

North Shore councillor Chris Darby, who is deputy chairman of council's infrastructure committee, says a draft report by Australian researchers shows Auckland is "not cutting it" protecting waterways.

"There's information in that report that shows we're doing extremely poorly," he says.

The council-commissioned report from three academics at Monash University in Melbourne, says Auckland is stuck in a "drained city" approach to dealing with stormwater.

But dealing with stormwater at or close to its source would prevent a great deal of runoff from roads, roof zinc, nutrients and other pollutants being piped into waterways, Darby says.

More than 10 kilometres of natural stream systems are being piped over every year, he says.


And non-separation of stormwater and sewerage systems is making our streams vulnerable to sewage overflows every time a downfall hits, he says.

Northcote College science teacher Kit Hustler says native fish in Northcote's Le Roys Stream haven't recovered after being "really nailed" by an overflow in 2012.

Hustler, who frequently visits the stream, says he's regularly greeted by the whiff of sewage.

"All it takes is one burst sewerage pipe on one overflow and all that sewage goes into that stream."

Although there are examples of good water-sensitive works such as open-airing streams in Torbay and installing swale systems in Greenhithe, other projects show no change of approach to stormwater, Darby says.

A stormwater retention pond completed this year at the base of Forrest Hill Rd which intersects with Wairau Rd is "a mess", he says.

The pond shows a failure to deal with upstream water contaminants and reflects the city's, "far too common approach delivering ordinary 1970s stormwater solutions", he says.

Darby is unsure of ratepayer costs on implementing the report's recommendations, but says fixing the stormwater system and taking a water sensitive approach would benefit all Aucklanders.

North Shore Times