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I live near what used to be several of these - Kaiapoi Island,Coutts Island, McLeans Island, Templar Island, no doubt forgetting some. Created by the Waimakari
by EdwardDiego 2y ago
I live near what used to be several of these - Kaiapoi Island,Coutts Island, McLeans Island, Templar Island, no doubt forgetting some.
Created by the Waimakariri River splitting into 3 branches as it neared the ocean.
They're no longer islands as the two side-branches of the river caused repeated severe floods in colonial days, so large civil engineering efforts went into restraining the river, ultimately leading to the south branch and north branch being blocked by large stopbanks and riprap cassions.
Both branches were then utilised to drain water from high fertility but swampy ground.
Because NZ's braided rivers lend themselves to wandering channels, we've still got some decent sized river islands - Rākaia Island, Rangitata Island.
- robocat 2y agoFor fun include Banks Island? I'm in Akaroa today! The Waimak has drifted over a bunch of the plains - ages ago didn't it go through West Melton to Lake Ellesmere?
- EdwardDiego 2y agoYep, that is the channel blocked off at Templar's Island! And if you get onto LINZ website, and grab their LIDAR data and visualise it, you can see all the old channels it has carved across the Plains, including ones right through CHC airport into the headwaters of the Avon (this is the route the Waimakariri took when it flooded Christchurch in the late 1800s). As for Banks Island, well it was an island back in the day, not sure how many thousand years ago that was though. PS, if you're in ChCh and tech, feel like we might know each other... love how small the net can make the rather large world.