When to let the river erode — ASN Events

When to let the river erode (10805)

Ian D Rutherfurd 1 , Geoff Vietz , James Grove , Ross Hardie
  1. University of Melbourne, Carlton, VIC, Australia

One of the key contributions that geomorphologists bring to river management is their predictions of what will happen to erosion and sedimentation if you do nothing. Some rate of erosion and sedimentation is considered to be essential for a naturally functioning stream. However, many streams have been stabilised so that these processes do not occur. This presentation explores the situations when managers could decided not to stop erosion processes. We describe five situations where erosion could be allowed to continue:
1. Where this is a natural process and there is no clear damage done to humans.
2. Where there are benefits to the erosion.
3. Where the erosion rate will decline over time so it is cheaper to let it happen
4. Where it is eroding now but it is better (cheaper?) to provide a buffer in which the erosion can happen.
5. Where it will erode in the future and we have buffered early.
You will see that the erosion question is intimately associated with the buffer question – how much room can we give the rivers to move?