Shiny Black Squiggles a Stitch in Time

Council staff taking measures to reduce road slips on tar seal roads when the rain finally comes.
Shiny black squiggles may be secret saviours for Whangarei's tar seal roads when the rain finally comes.

Whangarei District Council infrastructure services manager Simon Weston said the prolonged dry summer was causing the ground under the district's road network to dry out, causing cracks along road surfaces.

Mr Weston said the cracks often happen where roads are on the sides of hills or are built on fill. If rain penetrates these cracks they can form a slippery surface under the ground and the road can fall away.

Since January council contractors have been pouring a special rubberised emulsion into the cracks. The emulsion fills them up, sticks to their sides and is able to expand, keeping the water out and preventing a slip.

The emulsion has been laid along almost five thousand metres of cracks in roads in the Whareora and Abbey Caves areas, Whangarei Heads road from Scott road to Pataua South, at Cullen road (Waipu), Weir crescent (at the back of the airport), from Cliff street to Kaiwaka road.

Stormwater drains and culverts are also being inspected to ensure they are clear of debris and blockages that could cause flooding and washouts if the district is hit by a deluge.

"Normally leaves and other debris washes away with regular rain and does not get a chance to build up, but with the dry weather debris has been collecting in some areas," Mr Weston said.

"We're also heading into autumn when leaves always cause a few problems. Our people have been out and about cleaning up potential problems spots and we encourage people to do the same around their properties to avoid floods and problems if we do get a big downpour."

Mr Weston said council staff hoped the drought will break gradually and steadily, giving the ground time to slowly regain its moisture, rather than getting a huge deluge causing costly damage to the roading network.