This is less a separate programme than a constraint threaded through the other five. A planting calendar built on the rainfall pattern of 1995 will fail.
What has changed
Annual rainfall across the catchment ranges between roughly 690mm and 1,300mm depending on where you stand. That range has not collapsed. What has changed is the distribution: the onset of the rains is less reliable, individual events are heavier, and the dry gaps between them are longer.
Heavier events on bare ground move dramatically more soil than the same total spread over more days. So the same annual rainfall now does more damage to an unprotected bank than it used to, which raises the value of the buffer work rather than lowering it.
Longer dry gaps also kill seedlings. Our 61% twelve-month survival is in significant part a dry-season figure, and it is why we plant early in the wet season rather than at the convenient moment.
When the rain arrives, then and now
Monthly rainfall across the catchment. The annual total has not collapsed — what changed is the distribution. Wet months are wetter, dry months drier, and the gaps between are longer.
How this changes what we do
- Planting is timed to the actual onset of rains, confirmed on the ground, rather than to a calendar date.
- Species selection weights drought tolerance more heavily than it did three years ago.
- Buffer widths on steep or exposed stretches are wider than the statutory minimum, because the minimum was set for a gentler rainfall pattern.
- Rainwater storage is sized for a longer dry gap than historical averages would suggest.
- We budget for replacement planting as a standing cost rather than an exception.
Restoration is climate adaptation
A vegetated bank absorbs a heavy rain event that a bare one sheds. A functioning wetland stores water through a longer dry gap. We do not run these as separate programmes because they are not separate things.
Support work that assumes a harder decade
Planning for the rainfall we used to get would be cheaper and would waste your money.