Angry New Brighton residents say lack of drainpipe maintenance caused flooding

By Adam Burns

Frustrated New Brighton residents believe a lack of drainpipe maintenance is leaving the area needlessly exposed to flooding.

Heavy rain fell in the city on Tuesday morning, resulting in shin-deep flooding across parts of New Brighton.

The flooding subsided within a couple of hours after local authorities rushed to clear the outflow pipes which had left parts of Marine Pde and Pacific Rd awash.

• Flooding in coastal Christchurch

The affected roads had been reopened by the afternoon.

An update from Christchurch City Council staff that day explained fallen leaves blocked some sumps which slowed the drainage of surface water.

"Out east we are aware of a couple of locations where surface flooding occurred, however, contractors were on site early this morning managing traffic and clearing the key outfalls.

"Once this occurred the water drained away quickly."

Some residents RNZ spoke to explained this had become the norm when the area received heavy rainfall.

But North Beach Residents' Association chairperson Kim Money said the lack of maintenance for sand-blanketed outfall pipes could leave homes vulnerable.

"It will go into houses," she said.

"It's certainly something that frustrates me immensely because I understand it is something that is a relatively easy fix.

"The longer it takes the council and [Citycare] to come and clear the outpour drains on the beach, the larger the buildup of water on Marine Parade.

"It needs to be addressed straight away... it affects residents all the time."

Money explained the buildup issue was symptomatic of an "accreting" shoreline.

A NIWA report commissioned by the Christchurch City Council in 2018 suggested the majority of the city's coastline was experiencing accretion, where the shoreline builds up as the coast advances seaward.

"As soon as we get those ocean outfall pipes covered in sand, the water just can't get out from the street," Money said.

"The frustrating thing is that this whole thing is avoidable, by clearing the outfalls before the rain comes."

Money said a proposed extension of the outflow pipeline at Cygnet St could mitigate some of the problem, or reallocating the maintenance burden to coastal community park rangers.

The council said in a statement the surface flooding was due to leaves blocking grates and the ocean outfall being covered in sand.

Contractors were on site about 8.30-9am and cleared the grates and ocean outfall at the end of Cygnet St.

The surface flooding was all cleared before noon.

Prior to any significant events city council contractors proactively clear key drains, grates and outfalls.

"When we clear the outfalls along the coast our contractors need to do this following a high tide as if we do this at the wrong stage of the tide then they will just get covered in sand again," a city council spokesperson said.