Source: Radio New Zealand
Little River, about 30km south of Christchurch, was flooded in February and also in May 2025. RNZ/Nathan McKinnon
The Christchurch City Council disagrees with Little River residents who say flooding in the Banks Peninsula town could have been mitigated by opening a nearby lake.
Little River, about 30 kilometres south of Christchurch, was badly flooded in February and last May. Locals claim opening nearby Lake Forsyth to the sea could have reduced flooding in the town.
Little River Cafe and Store owner Cameron Gordon – whose business and home was flooded – was one of a number of local residents who said delays in opening Lake Forsyth contributed to flooding in the town.
“Once that lake opened … it drained away pretty quickly,” he told RNZ earlier in February.
The town was also badly flooded last May with residents raising concerns Lake Forsyth was opened too late.
But Christchurch City Council head of three waters Gavin Hutchison said the recent weather event was significant and even if Lake Forsyth had been lower, or open at the time, Little River would have still experienced extensive flooding.
“While both this event and the May event caused flooding in the township, the most recent event had a much greater impact on Little River and the surrounding area,” he said.
Lake Forsyth in Banks Peninsula following the bad weather. Nathan Mckinnon / RNZ
The council also did not believe the lake contributed to the flooding in May.
“Lake levels were low at that time and the flooding was caused by the amount and intensity of rain with water flowing through the township,” Hutchinson said.
“Ahead of the recent rain, the lake level was within an acceptable range. Even if an attempt had been made to open it earlier, sea conditions meant it was highly unlikely the opening would have been successful.
“The council has previously looked into the role of lake levels in flooding. This confirmed that the lake does not cause flooding in the township itself, though high lake levels can affect low lying land at the head of the lake. One change already made is a winter trial of opening the lake at a slightly lower trigger level,” Hutchison said.
Lake Forsyth is about a kilometre south of Little River and is fed by the Okana and Okuti Rivers.
The only thing separating its southern banks from the Pacific Ocean is the gravel of Birdlings Flat Beach and a canal connecting the lake and ocean that could be opened by diggers when needed.
The resource consent allowed the council to open the lake when it reached 2.3 metres above mean sea level in spring and summer or 2.7m in autumn and winter. But it could also be opened if a storm was predicted to bring it to that level or threaten inundation.
The council opened the lake on 17 February after it had peaked at about 4.4m and Little River was already inundated.
The lake was opened in May last year after peaking at 4.15m with some local businesses already a foot under water.
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand
