Whau reporting area

Whau Local Board

State of Auckland

Freshwater
Report
Card

Area Grade

C

July 2014

What makes up this grade?

What-makes-up-this-grade_FRESH-WATER-WHAU-2014

The overall grade is made up of five indicators:

Water quality: Water samples are tested for temperature, oxygen concentration, turbidity and the levels of pH, ammonia and nutrients (nitrogen and phosphorus). The results of this testing are compared against guidelines for Auckland to produce a water quality index.

Flow patterns: This involves monitoring the hydrologic connectivity of the river to upstream and downstream reaches and the floodplain using the Stream Ecological Valuation (SEV), which is a method of assessing the ecological health of our rivers.

Nutrient cycling: This involves monitoring the inputs and processing of minerals, particulates and contaminants using the SEV biogeochemical functions.

Habitat quality: This involves monitoring the diversity and quality of habitats using the SEV habitat provision functions.

Biodiversity: Field assessments and samples are collected to assess the type and amount of native plants and animals using the SEV biodiversity functions.

Quick facts

The reporting area covers 27KM2 representing 0.5% of the region

The land cover is mainly urban (93%) with small pockets of native, exotic and pastoral vegetation

The extent of impervious surface (hard surfaces) is very high (52%) when compared with the regional average of 9% 

Annual-rainfall_FRESH-WATER-WHAU-2014

Whau monitoring sites map

Whau monitoring sites map

Monitoring background and interpretation

Auckland Council’s State of the Environment (SoE) monitoring programme has been building a record of Auckland’s environment for more than 25 years. This information is critical to the effective management of Auckland’s natural environment, after all, you
can’t manage what you don’t monitor.

The monitoring programme shows there is a strong relationship between the health of rivers and the type of land cover in the surrounding catchment. Rivers that drain through forested catchments (particularly native forests) typically have excellent water quality and ecology, while rivers that drain from urban catchments typically have poor water quality and ecology.

The health of the Whau reporting area’s rivers is considered to be impaired. Urban development has led to a high level of impervious surface in the area, which prevents rainfall from soaking into the ground. This has follow-on effects for rivers in the area leading to high water temperatures, changes to the natural flow patterns and increased pollution from contaminated stormwater. 

Wai Care Whau

wai care logo

Wai Care is a water quality education, monitoring and action programme managed by Auckland Council, for schools and community groups in the Auckland region.

The programme aims to educate people about freshwater issues and encourage and facilitate action in the local community, from water quality monitoring to streamside planting and litter clean-ups.

The following table shows achievements of the Wai Care Programme in Whau during the 2013/2014 financial year. 

TABLE_FRESH-WATER-WHAU-2014

Highlights

During 2013/2014, Waitakere College students undertook restoration planting on the Rewarewa Stream, in the Whau River catchment. They planted a total of 500 native trees as part of a practical component in their biology work. 

New Lynn Primary School’s “Water Warriors” group also began investigating water quality in the Rewarewa Stream, meeting regularly with Wai Care to learn how to monitor using the Wai Care monitoring protocol.

For more information on Wai Care, or to view site data for your area, go to www.waicare.org.nz or call 09 301 0101 and ask for Wai Care.