The Star: July 11, 2024

Thursday July 11 2024 The Star
Latest Canterbury news at starnews.co.nz
NEWS 5
Full sewerage system blocks housing
development in face of intensification
• By Niva Chittock
PARTS OF Christchurch are
off-limits for further housing
development because the sewage
system is full.
The city council has been
pushing back on new central
government rules for housing
intensification, but its exemption
runs out next year.
An independent investigator
was appointed and the council
held hearings earlier this year
on the proposed changes, called
Plan Change 14.
More policy changes were
announced by the Government
last week. ‘Going for Housing
Growth’ will require major
councils to have 30 years worth
of land zoned for housing, allows
more mixed use of land so neighbourhoods
can have cafes and
dairies, and removes minimum
size and balcony rules for apartments.
City councillors are under
pressure to get the ball rolling,
but in parts of Christchurch,
infrastructure is at capacity.
When heavy rains hit the city
in 2021, some suburbs could not
flush their toilets because the
wastewater pipes were full.
The city council resorted to
using sucker trucks to keep the
pipes moving.
Aranui, Shirley and Prestons
all had vacuum sewer systems
installed after the earthquakes
– but they were built with little
room for growth.
Council acting head of
planning and consents Mark
Stevenson said the systems also
relied on an air-to-water ratio –
meaning they failed if too much
stormwater got in.
“To accommodate further
demand in the future, it would
require the whole system to be
upgraded simultaneously at a
PHOTO: GETTY
significant cost. It’s not a system
like other parts of the city where
we can dig up a pipe and just
replace it,” he said.
Replacing the systems was estimated
to cost up to $240 million,
the city council said.
It usually set aside less than
$50m for the entire wastewater
network over 10 years.
Mayor Phil Mauger was keen
to ditch the vacuum systems.
“I don’t like it, because I’ve laid
lots of pipes, I can tell you what
it’s like. We should go to a system
that we are using out in Halswell,
which is little pump stations for
every house,
which works
extremely well,”
he said.
The individual
pumps took the
pressure off
the wastewater
system at peak Phil Mauger
times, Mauger
said.
“They’re all hooked up to a
main computer here in town. We
can say ‘right, our sewers are at
capacity from six until nine at
night because everyone’s having
a shower’. We can press a button
and turn all those pumps off, because
they’ve got a wee tank that
can hold the stuff, then we can
turn them all on at three o’clock
in the morning and it makes our
pipes a lot more usable throughout
the day,” he said.
No other suburbs were at risk
of hitting their sewer capacity,
and the council was only approving
new housing where the
infrastructure could support it,
Stevenson said.
At this stage, that meant building
more around main public
transport routes, and in areas with
easy accessibility to services.
Ngāi Tahu Property had just
applied to build 55 residential
homes on the site of the former
Aranui Primary School – in a
wastewater capacity area.
It declined RNZ’s interview
request, but confirmed the application
had been lodged and said
it would await the city council’s
assessment.
RNZ had viewed its application,
which stated it was aware
the area’s sewage system was full.
According to the plans, each
house would have its own independent
pump unit, like those in
Halswell.
It was unclear where the latest
central government housing
announcement would leave the
city, Mauger said.
“Staff will now need to work
through the implications of the
announcement and brief us so
we get a full picture. Fortunately
we have over 30 years’ worth of
expected demand covered in
our existing zoning, and this
will only increase through our
National Policy Statement-Urban
Development proposals in
PC14,” he said.
The city council will vote
on some of the Government’s
proposed housing intensification
changes on September 4. –RNZ
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