Flooding forces family out of home again

When Anna and Josh Pedersen bought their property, lakeside views were not on the listing.

A month of rain fell across Canterbury from July 22-23, forcing the couple to move out of their Tancreds Rd, Ladbrooks, property with their three young children for the second winter in a row. 

“We have been in this property three years now – this is the second winter we have had a moat around our house,” Anna said. 

“This year in particular is worse. It has gone over our septic tank, we have to move the kids out and we can’t currently live where we are.”

Anna said it can take up to six weeks for their 4ha property to drain completely. They keep some animals on the property, including 12 cattle, sheep, and pigs. When the  flooding hits, the cattle and sheep have to be moved.

Said Josh: “All our animals as well, they are currently at the neighbour’s place, we can’t feed and hold them here.”

Anna said they won’t be able to bring their cattle back for at least a month to six weeks. 

She said if a solution is not found they may have to sell the animals.

The couple say the water comes from the Halswell River, which is 2.5km from their property.

Said Anna: “We have a big drainage system behind us. The Halswell River starts increasing in flow and actually comes up our drainage system. 

“It comes over the banks and floods our area. The rain stopped on the Sunday and (the water) kept rising until (Tuesday).”

The family blames Environment Canterbury which they say is not listening to their concerns over the flooding.

Said Anna: “We have had some dealings with ECan on these issues and they are telling us that our drainage system is working correctly. But this is not okay.

“I feel like they are just expecting us to put our heads in the sand and go away.”

ECan rivers manager David Aires said the drainage system is in good condition.

“The condition of Blacklers drain prior to this rain period could not have been better. 

“Weed-cutting had just been completed in the Halswell River, improving flood-carrying capacity and there was a relatively low lake level at Te Waihora/Lake Ellesmere.”

Aires said it was possible for water to flow back up the drainage system when the river was in high flood. 

“This property, along with others, is located in an area called Blacklers drain/Lethams swamp,” Aires said.

Anna and Josh Pedersen in front of an unwanted water feature. PHOTO: JOHN SPURDLE
Anna and Josh Pedersen in front of an unwanted water feature. PHOTO: JOHN SPURDLE
Aires said it is a low-lying natural ponding basin, prone to surface flooding in significant rain events. 

“As ground conditions have been wet to saturated for some time, even moderate rainfall is likely to cause surface water flooding.” 

Aires said there was “no immediate long-term plan” to address flooding in the area. When the Pedersens bought the property in 2020, they weren’t aware of the issues but knew the area was a floodplain.

Said Anna: “We understand that we live in the lower area, we understand flooding and surface flooding, but we are getting a phenomenal amount of rain and flooding and it’s not going away.”

Anna said flooding like this was expected once every 50 years in the area but “for the last two out three years we have flooded”.

Said Josh: “I think the obvious solution is a one-way floodgate on the Halswell River to stop the water coming up the drainage system,” he said.

“The Halswell River is full but not overflowing so there is capacity within to handle water.”

The Pedersens also found an ECan storm water discharge report from 2018, pointing towards increased development causing more water drainage issues in low-lying areas around the Halswell River.

Said Anna: “ECan knows about this because we have found a report online and it’s saying that all the new developments in Lincoln, Halswell, Prebbleton are raising their levels causing more flooding.”

The report points to subdivisions having an impact on drainage systems as the water flow increases. 

But Aires said a Halswell drainage scheme review was completed in 2019 after the report was written. The review investigated drainage and flooding in the catchment but put no firm proposals forward to improve it. The review also  showed protecting one area would displace floodwaters to other areas. 

“To avoid this impact, any flood protection proposal would likely require a multimillion-dollar solution. The main strategy for new development in the catchment is to avoid building in high-hazard areas,” Aires said. 

Aires said ECan would need to investigate the merits of a floodgate. He said the Halswell drainage network remains very sensitive to additional flow.

“New urban developments have to put in a high degree of attenuation for stormwater to avoid increasing flood flows, either as part of a consented stormwater management plan.”


Additional reporting John Spurdle, Public Interest Journalism Fund