Update #1 on Wetland Restoration Case Study 1 – near Heywood

Update #1 on Wetland Restoration Case Study 1 – near Heywood

Winter really did deliver a short but sharp burst for the south western corner of Victoria and our delivery of early works for the Wetland Restoration Project enabled us to capitalise on these conditions.  A couple of weeks ago I dropped in to our first case study site near Heywood to see if the water level had reached spilling point and, sure enough, it was trickling over.

Prior to spilling

Spilling at the restored sill height.

Looking toward the outlet at spill height

Like any wetland restoration project which involves the regulation of an existing drain, it is imperative that neighbours are consulted and that no unintended upstream inundation occurs.  In our planning for this particular site we factored in approximately 0.3 meters of free-board which, given the size of the local catchment, should be enough to prevent backwater effects and flooding back into the paddock next door.  The image below demonstrates our design considerations in action, showing the elevation difference between the restored wetland’s maximum water level after a heavy rainfall period and the neighbours paddocks.  As designed, the capacity for overland drainage from a low-lying area of the neighbouring farm hasn’t been compromised.

Elevation difference between restored wetland at spill level and neigbouring property allowing continued localised drainage

 

Lachlan Farrington