Room for the river: Is it time to re-think how we manage floods?
www.rnz.co.nz
Since the 1950s, the Ngaruroro River in Hawke’s Bay has been steadily and deliberately restricted to a channel half its former width. As the likelihood of extreme flooding increases, is it time to re-imagine the river’s future?

This is pretty interesting! I like the bits where they show the 1950s aerial view vs the present ones to show how the river changed.

  • TagMeInSkipIGotThis@lemmy.nz
    3·
    14 days ago

    That was the maths I was working with too - but seemingly there’s two parts to it, capacity between the banks and flow rate of the river in flood and for the latter wider is better.

    So presumably you can build lower, cheaper stop banks further apart for slower flood velocity and less risk of stop bank failure at the expense of more risk of stop bank overtopping.