The red line shows the gap in height between the present stopbank, and
a proposed new one. Comfortingly, perhaps, the highest flood ever recorded is well below the height of even today’s bank. The marker for the biggest flood I’ve experienced in my 17 years here is even further below. Mind you, that storm was still enough to flood large parts of Waiwhetu, Seaview and Moera - due in part to an overloaded Waiwhetu stream further down the valley. It has since been ‘renovated’, and is now less of a threat.
However, what I find most interesting is that the marker for the 1858 and 1898 floods (equivalent heights) shows how quickly and easily human modification of the landscape can dramatically change things - and cost human lives. John Easther, in a history of the Hutt River written for the Wellington Regional Council, said within two years of European settlers arriving in the Hutt Valley in 1840, ‘stripping of the forest had allowed the Hutt to erode the land and change course as never before’. In January 1858, the worst of a series of floods that affected the valley caused nine deaths and took out many bridges and roads, as the sign next to the riverbank marker testifies.The Māori name for the river is Te Awa Kairangi - ‘the river of great value’, reflecting a different relationship with the river. It’s now more commonly used by others too.
Reassuring as today’s marker and plans to raise the stopbank higher are, I
do wonder what impact climate change - whether 20, 50 or 100 years from now - will have on the level of safety offered. Land and people will be dealing with the double complexity of higher mean sea levels and more intense rain events. Perhaps the slow reforestation of the hills and better urban land and water management will also help - slowing down storm run-off and doing their bit to minimise, or soak up, carbon emissions. Only time will tell.
Poem - In flood
Its banks full
The river is a quiet fury
It must flow to the sea.
There is no argument.
