Riparian planting along Ōtukaikino Stream withstands flood
Story contributed by Kathryn Thorne, Papanui Baptist Earthcare Group.
On Saturday, September 26, 2020, members of the Papanui Baptist EarthCare Group and Friends, headed out with spades and gloves to the Ōtukaikino Stream, which flows into the south side of the mighty Waimakariri River, not far from the new Motorway north. Under the expert guidance of Greg Stanley (ECAN - Environment Canterbury, and member of our church whānau), we planted around 250 native trees (māhoe, tōtara, kahikatea, mātai and kaikōmako).
In May 2021, Canterbury experienced a 1-in-10 year flooding event, where the Waimakariri swelled, leaving its usual bed and spilling into the neighbouring berm lands. Greg reassures us that the Waimakariri River “… didn’t actually breach its actual banks anywhere. The reality is that we are very well-protected. The Waimakariri has a massive capacity and the recent flood sat below a third of the total. I believe we have sufficient protection for a 1-in-2000 year event. However the same is not true further south where there are fewer funds available for flood protection.”
The result of the flood was that these young trees we had planted ended up under 1.5 m of water for a 24-hour period on two occasions. If you look closely at the photo (supplied by Greg after those floods), you will notice the stand of poplars in the distance, and you will see the muddy tide mark, quite a way up their trunks! Amazingly, the trees have survived well, often being adapted to withstand short flooding events (something your garden rose bush would probably not do!) In fact, the plants are thriving under a fresh bed of silt and the first hints of new leaves are starting to appear!”
