Gully intervention prevents more than 10,500t of sediment reaching the reef
On-ground remediation works include five large-scale gullies and 20 small-scale gully sites.
Collectively, these gully works treated more than 11,000 linear metres of gullies eroding from 54 gully heads. It is estimated the work has prevented 10,500 tonnes of fine sediment from reaching the Great Barrier Reef each year.
LARGE-SCALE GULLIES — five gullies remediated
The dramatic transformation at Mt Wickham Station one wet season after a large-scale gully was remediated.
Large-scale projects required technical designs to be developed. Remediation techniques included combination of grade control rock cultures, re-contouring of the rehabilitation area, soil amelioration and revegetation using a range of pasture and legume species.
Glen Bowen gully remediation site before on-ground works began and when the work was almost complete.
SMALL-SCALE GULLIES — 20 gullies remediated
Two rock chutes and a bund wall divert water away from the gully, directing it into the chutes.
Remediation options used on small-scale erosion features and gullies included:
- diversion banks and water spreading structures;
- sediment or silt traps;
- direct on-ground rehabilitation;
- within-gully management structures such as rock armouring, gully reshaping;
- contour ripping and re-seeding pasture; and
- permanent riparian fencing.
Diversion banks with level sills slow and spread water on black soil flats and allow sediment to be trapped in the borrow pits and level sills.