No cheap fix for flood trouble-spots in Chch
August dawns with the welcome promise of spring weather waiting in the wings, after the ravages of an appallingly gloomy, rain-drenched July. The Christchurch City Council has made excellent headway in the past seven years to mitigate the worst excesses facing flood-prone hotspots, post-quake.
That colossal package of work continues under the Land Drainage Recovery Programme, which comes with a $220 million price-tag over the next nine years.
Understandably, the priority has been to prevent floodwaters breaching the floor levels of people’s homes – and those endeavours have largely been successful, as we have seen in the Flockton St area and around the Heathcote River.
The current priority is to minimise the extent of flooding to people’s gardens and backyards during extreme rainfall events.
But beyond residential impact, the rapid sequence of repeat winter flooding in Christchurch has left glaringly exposed some other nagging trouble-spots in its wake.
The low-slung twin-bridged curving roadway of Fitzgerald Ave, by the Avon River, was widely ridiculed as an epic design failure following its post-quake rebuild.
It has been repeatedly closed in heavy rainfall events ever since.
The council’s head of transport, Lynette Ellis, tells me there’s no funding allocated for further works at this location, although the twin bridges will be replaced in seven years at a cost of $30m.
Another recidivist and unresolved flooding sore point is Edgeware Village, where roadside flooding monsters a variety of businesses, but most notably Peter Timbs Meats.
The council’s head of Three Waters, Helen Beaumont, tells me the butcher shop ‘‘is located at the lowest point in the catchment and the floor of the shop is at the same level as the back of the footpath’’.
Beaumont says ‘‘upgrades to the local kerb and channel, sumps and pipe network will not address this issue.
‘‘A wider flood alleviation scheme or changes to floor levels would be required to materially reduce flood risk in the area.’’
The drainage network of St Albans Creek is actually higher than low-lying Edgeware Rd, between Colombo St and Sherborne St, so in high rainfall, gravity drainage doesn’t send the water to the creek.
Instead, it ponds on the side of Edgeware Rd. Beaumont confirms that the Land Drainage Recovery Programme did an investigation to look at options to improve stormwater and drainage in Edgeware Village as part of the wider Flockton area.
Upgrading the gravity network and installing a new pump station to take the water directly to the Avon River was estimated to cost $12-$15m.
However, in 2015 the council’s final decision was to upgrade Dudley Creek and St Albans Creek only up to Hills Road.
It did not include the option of improvements to Edgeware Rd.
It was a lamentably short-sighted decision – a classic case of kicking the can down the road.
Constructing an alternative route to divert the water to the Avon River now carries a cost estimate of $23m.
Constructing an alternative route to divert the water to the Avon River now carries a cost estimate of $23m.
Butchery owner David Timbs tells me he has considered raising the low floor level of the shop, ‘‘but it would not solve the issue, as the water would still gather to such an extent that flooding would occur’’. Timbs describes his interactions with the council as ‘‘mixed’’.
He’s calling for greater transparency on the Edgeware/St Albans drainage and flood plans.
‘‘We aren’t simply asking the council to fix the problem, but to discuss the options for a solution, so we can determine what course of action is the most affordable, cost-effective and time-effective.’’
Innes ward councillor Pauline Cotter is hopeful that after more than a year of community board-instigated requests for information and briefings, a full report will go to council on September 8.
Fellow community board member Ali Jones, who is contesting the council ward against Cotter, tells me ‘‘it’s the lack of urgency and incredibly slow progress that’s so frustrating’’.
Cotter says she is ‘‘very concerned’’ that businesses like Edgeware Liquor and Peter Timbs Meats are ‘‘taking more and more financial hits.
‘‘I will be advocating strongly for the Edgeware Village flooding problem to be sorted as quickly as possible.’’
Business viability is at stake. It would be a travesty for Edgeware’s vitality to lose such a legendary family business.