Erosion control on farms
Erosion control on farms
Managing impacts on threatened species by reducing erosion on farms
Collaborations -
LP027-003
The issue
A 2018 DPI Fisheries report described a sediment slug in the Lachlan River that starts at Hovells Creek and continues for more than 150km downstream almost to Forbes. The reaches of the river starting at Hovells Creek and Boorowa River are a major source of the sedimentation. Sediment loss from erosion gullies on farms makes a huge contribution to this. The slug has many impacts on the threatened species of frogs, fish, birds and riparian vegetation of the Lachlan including filling in all the refugia (places where fish can survive when river levels are low) and Murray Cod breeding holes along the 150 km stretch.
The solution
HCLG is proudly supported by two grants from the NSW Environmental Trust and one from Murray Darling Healthy Rivers to do earthworks in erosion gullies on 18 properties. The works are aimed at slowing the force of the water through the gullies to reduce erosion. They include dams with trickle pipes, a rock-lined channel into an existing dam and ripping and planting a steep hillside. Following works, landholders plant trees and shrubs and seed with pasture seed to stabilise the disturbed ground. We also worked collaboratively with Hilltops Council who did flood mitigation works on their land next to some of our gullies. We were very pleased to also be supported by South East Local Land Services who provided funding for seed, plants and fencing for stage 1 of the project.
The impact
Earthworks have been done at ten sites so far. They have been tested by extremely heavy rains and have performed well. NSW Soil Conservation Service estimates that we are currently losing up 2400 tonnes of sediment per year from the 18 properties in our program, so we have achieved a good reduction of sediment going into Hovells Creek and the Lachlan so far. We have also improved the resilience of the properties to drought by keeping soil and water on the property. Importantly, we are also reducing a key threatening process for the many threatened species in those waterways.
Learnings
We have had many months of delays while the ground was too wet for works to be done. We learned the value of patience and the importance of keeping in regular contact with funding bodies about delays. We also benefited from liaison with key stakeholders. Previous attempts to collaborate with Council had been unsuccessful but this time we coincided with Council receiving flood mitigation funding. Their works slowed water from road culverts before it reached our gullies and made a big difference to how well our works performed.
Key facts
- A 150km sand slug in the Lachlan River impacts threatened species
- Much of it comes from farms in the Hovells Creek catchment
- HCLG is doing erosion control works on 18 properties over four years
- This is a collaborative project