Cox's Creek improvement project
Background |
Options assessment | Proposed
works | Expected benefits
Options assessment
In 2006
a working party of representatives from Auckland City Council, Metrowater and
Watercare Services was set up to address the creek's odour and water quality,
and general appearance issues.
Following on from previous work, solutions were developed and assessed using the
following criteria:
- potential to improve water quality in Cox's Creek
- impact on amenity values
- enhancement of habitat potential and environmental values.
It was
found that the tidal flow at Cox's Creek needed to be restored. The following is
a summary of the options the council has investigated to determine how to best
achieve this goal.
Option 1
Minor stream works
This would involve removing the worst section of
constriction from Cox's Creek, located approximately 70m downstream from the
Richmond Road scour pool, near the end of Webber Street. While this would
increase flushing to a degree, it is believed that significant ponding of
stagnant water would still occur, so this option was rejected.
Option 2
Medium stream works
The upper section of Cox's Creek would be dredged from the
Richmond Road scour pool to approximately 580m downstream, which includes
removal of the constriction point identified in Option 1. This option has been
identified as the most effective approach, and will be put into action as part
of Cox's Creek improvement project.
Option 3
Major stream works
This would incorporate Option 2 but also involves lowering
the West End Road culvert and dredging the entire length of the channel, plus a
section of the Cox's Bay tidal flats. Option 3 was rejected because of the large
volume of sediment removal required, high cost, and ongoing dredging
requirements into Cox's Bay. Modelling showed that the extra works would not
result in a significant improvement to the performance of the stream.
