Decorative photo

The Selwyn District Council wants to be better prepared for future flooding events by adding a cache of deployable water-filled flood barriers.

Selwyn Emergency Management Team recently tested the 14.5m-long ARK barriers, which can be connected and extended to protect large areas, and are filled with water to keep them in place to contain or divert flood waters, in a similar fashion to sandbags.

“The Emergency Management Team has been looking at opportunities to increase resilience, and we believe these temporary barriers give us another tool to reduce the risk of flooding from overland flow and storm water flooding,” says Selwyn Civil Defence Controller Al Lawn.

“They can be filled from fire hydrants, tankers or other water sources via a pump and hose. After deployment they can then be emptied and packed away for the next event,” says Lawn, who explains that not using sandbags adds several other benefits.

“Sandbags take a lot of time and resources to fill up and after the floods they are often contaminated with sewage, so you can’t just empty them out in a paddock.”

Tim Mason, the Council’s Executive Director for Infrastructure and Property, explains that almost every area in Selwyn has been prone to different levels of flooding in recent times,  most notably the state of emergency flooding in May last year.

“Flooding is the most common and frequent threat in Selwyn and our team keeps learning from every event. Our water engineers now have a better understanding where the water wants to go and have created maps, so all the local volunteers know in advance where to put the barriers,” says Mason.

Civil Defence controller Lawn explains that putting up barriers without any planning, wherever the water may pour out of creeks or paddocks can sometimes create bigger problems in other locations.

“When water is diverted it can have unintended consequences if it is diverted to areas where there are other assets. With pre-planning and training our Fire and Emergency  New Zealand  brigades, Council NZ Response Team and our contractors will be well placed to deploy the barriers in places which help reduce the consequences of flooding.”

VIDEO: New Flood Barriers For Selwyn

Lawn noted that the barriers are still a “proof of concept” project.

“In a large flood event involving many parts of the district there will simply not be enough barriers to divert all the flood waters. They are not the ultimate silver bullet, but part of an ongoing strategy to mitigate the risk of flooding across the district.”

Lawn adds that the flood barriers will help to close the ‘protection gap’ between the modelling of flood risk and the hard infrastructure that could be a long-term solution to mitigate that risk.

The PVC flood barriers have been used extensively overseas for years, but only recently Tauranga-based company Tarpaulin Markers started producing the New Zealand version, which has also been trialled by Wairoa and Hawkes Bay councils in response to Cyclone Gabrielle.

Council’s Chief Executive Steve Gibling says flooding is one of the most common natural hazards facing communities across the district, and Council is committed to continuing to invest in practical measures that help reduce its impact.

“We know floods are a risk for many of our communities, so it makes sense to invest in tools and technology that strengthen our ability to respond when severe weather hits.

“These barriers are a practical addition to our emergency management toolkit. They can be deployed quickly, reused repeatedly and help protect people, property and community assets during flood events.

“Good preparation and early action can make a real difference when communities are under pressure.”

Last modified: 28 Sep 2026 9:51am