In this zone 3 settlements used rivers to protect  their ships.  We see how floods and bed-load deposits have taken huge a toll.

Studies:
We visit two of these harbours to see their advantages and difficulties caused by bed-load movements with floods, storms, bars, etc.  Here we learn how these harbours are maintained and the horrible results when maintenance is ignored.

There are still many river harbours in the world today - all have to consider the dynamics we learn here.

See also:
● Harbours NZ
● Rivers NZ
● Transport NZ 
● Settlements NZ
● LINK Story of the port of Greymouth.