Flood gate testing

Citycare Water staff have a reputation and legacy as first responders during emergencies and extreme weather events and they also actively prepare to manage risk and protect our communities should these events occur.

A good example of disaster prevention work is the New Plymouth team’s recent assistance with the testing of new flood gates in the Waitara township bridge that crosses the Waitara River.

“This test came at the perfect time given the recent floods our communities have faced in New Zealand,” Taranaki Branch Manager Tony Ewens says.

The new flood gate test was carried out by Taranaki Regional Council (TRC) with Citycare Water involved in preparing the traffic management, road closure and water supply, Tony says.

“Citycare Water assisted by providing water supply from tankers, to simulate water flows, to test the effectiveness of the brand-new barrier system,” he says.

In 1965 the township of Waitara was completely flooded, causing large scale devastation, and there were major floods in the 1970s, too.

Since that destructive event, the local councils have installed stop banks to prevent disaster.

The new removable barrier is the final part of a multi-year upgrade of the Lower Waitara River Flood Control Scheme by the TRC, which also included raising floodwalls and stopbanks, upgrading rock linings and rock groynes, and installing floodgates to prevent floodwater getting into stormwater pipes, TRC River Manager Ruan Smal says.

The barrier will be deployed at the town end of the bridge if extreme rainfall ever results in the Waitara River threatening to rise above the bridge deck, Ruan says.

As the bridge is a significant road to the town, the barrier test was a carefully planned and well executed project to reduce disruption to local business and emergency services.

The barrier itself is stored nearby as a lightweight kitset and the test was to ensure it can be deployed quickly and securely.

“The bridge would have been a weak link if we didn’t have a way of containing the flow there,” Ruan says.

“The temporary barrier itself may not look high but it offers significant extra protection considering the river’s depth, width and speed. A smallish rise in the flow above the bridge would represent a considerable volume of extra floodwater.”

A barrier is needed only on the town side of the bridge, as the eastern side is higher, and floodwaters would not overtop at that end.

To find out more about the Waitara scheme and other Taranaki Regional Council flood protection schemes, go to www.trc.govt.nz/you-and-your-river/