Report 8 - Executive Summary
Receiving Environment Quality in Waitakere City
In preparation for Waitakere City Council's 'Comprehensive sustainable action
plan' for stormwater, Kingett Mitchell & Associates Ltd was given the task of
developing a methodology and process for ranking catchments, with respect to
receiving environment quality, within the City. The methodology associated with
this 'initial task' required that two sets of information be collected. These
were:
- Identification of stormwater issues within individual 'super catchments'
and an assessment of their importance
- An assessment of stormwater effects on aquatic environments.
The assessment was based primarily on field observations, sampling and
analysis of key parameters that reflected stormwater issues. It also drew upon
existing data/information. The information also included stormwater issues that
had previously been identified for the various super catchments (stormwater
management units) within the study area.
This report and environmental assessment provided information to assist the
development of a water quality programme for Council (refer Report 9: Stormwater
Monitoring Programme). In particular, the assessment assisted in identifying
appropriate monitoring parameters for both freshwater and marine receiving
environments and provided a basis for the selection of monitoring sites.
The primary objectives of the preliminary environmental effects assessment
were to:
- Assess the condition of aquatic environments (both freshwater and
marine) that receive stormwater from urban catchments within Waitakere City
- Relate the condition of the receiving environments to stormwater
influences within individual contributing catchments
Super-catchments (stormwater management units) were grouped according to
their drainage system (watersheds) and the drainage linkages between the various
super-catchments summarised. An evaluation of the super-catchments showed that
they could be categorised into five broad categories, based on their receiving
environments. The primary focus of the study was on the Waitakere City urban
environments and catchments were selected to reflect the land-use within the
City.
Land use issues and sampling site selection is covered in the report, along
with sampling and analytical methods for both freshwater and marine resources.
Fresh water quality encompasses a wide range of parameters from pH, conductivity
and temperature to suspended solids and metals. There are also chapters on
marine biological resources; freshwater habitats; sediment quality; and
catchment evaluation, which includes methodology and site rankings.
Commentary on Report 8: prepared by Earth Consult
EcoWater commissioned this report to provide a commentary on the findings of
the Kingett Mitchell investigation and in particular to provide an overview of
the significance of the findings for the stormwater strategy. It is important
that it be read in conjunction with the Kingett Mitchell report.
Report 8 - Full Version
Receiving Environment Quality in Waitakere City
For a copy of this report or any further information please
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