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Titahi Bay catchment sampling

Titahi Bay is located on the Peninsula to the north of Porirua. The area has been extensively developed since first settlement and is now predominantly residential housing with a number of schools and parks in the area.

The water quality in the Porirua area has been analysed in the Te Awarua-o-Porirua Whaitua Implementation Programme (2019), ranking different water quality indicators from A through to E. Titahi Bay has been included as part of the Te Riu o Porirua water management unit, which is comprised of mainly urban catchments in the Porirua area.  The Te Riu o Porirua water management unit has been graded as an E for E.coli, D for Copper, and a D for Zinc. These values indicate that the water quality in the area is heavily degraded, therefore measures need to be implemented to improve the water quality.


Porirua Wastewater Treatment Plant

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Catchment Area


Water quality routine sample testing - how it's reported

We take regular samples of water quality to look into the level of E.Coli for freshwater and Enterococci for marine waters, which indicate whether the water is safe for swimming and other recreational activities.

The way in which we test and classify when water is safe, or not safe depends on how the stream or waterway is classified (i.e. either as a ‘consented stormwater discharge’, or a Marine and Freshwater recreational area). Find out more about our reporting requirements below:   

Consented stormwater discharge

The South Beach Access Culvert is a stormwater outlet that is covered under a resource consent approved by the Greater Wellington Regional Council (GWRC) for stormwater discharge.

The consent requires us to monitor beach water quality on a monthly basis at four designated sites, Toms Road, Bay Road, South Beach Access, and South Beach Access Culvert outlet. The consent also requires us to undertake an investigation if the routine E.coli monitoring at either of these sites identifies a single result >10,000cfu/100mL or two successive monthly E.coli results >1,000cfu/100mL. These investigations are only initiated if the sample was not influenced by rainfall, which is cross checked with the rain gauge at Taupo Stream at Whenua Tapu. 

Marine and Freshwater Recreational Areas

Titahi Bay is classified as a Marine Recreational Area

For areas classified as a Marine and Freshwater Recreational Areas, Enterococci sample readings equal to or less than 140 cfu/100 mL, or Equal to or less than an E.coli level of 260 cfu/100mL give a suitable for swimming classification. Where a Enterococci reading is greater than 140 / 100mL, or more than an E.coli level 260 cfu/100mL, the area is given a Caution Advised classification. Finally, where an Enterococci reading is more than 280cfu/100mL, or more than an E. coli level of 550 cfu/100 mL, it is given an unsuitable for swimming classification.

These classifications are recorded and reported by LAWA (Land, Air, Water Aotearoa) and made available through their website).

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E.coli rule of thumb guide (In development - will be updated)


Report an issue

If you believe this relates to a specific consent, please reference that consent number


Greater Wellington Regional Council Pollution Hotline

0800 496 734