Unwanted tree stumps restore river health

Making a Difference -

LLCI033-081

Unwanted tree stumps restore river health

The issue

The lower Nambucca River estuary supports award-winning Oyster farming, attracts recreational fishers and tourists throughout the year and provides essential regulation and support services to the entire river system, but despite the importance of this river reach, it has been under growing threat. An increase in boat traffic, combined with the extensive clearing of riparian vegetation, has rendered the intertidal zone in the lower Nambucca River estuary susceptible to erosion and bank retreat.

The solution

To address this issue, the Lower Nambucca Fish Habitat and River Foreshore Restoration Project sought to re-establish ecological equilibrium along 400m of river, selected due to the river condition, landholder willingness and its strategic location in the Oyster production and recreational fishing zones.

The impact

The construction of rock fillets and toe revetment aimed to give the mangroves a chance to establish, thus not only improving the habitat value of the foreshore, but also buffering the banks from wind chop and boat wake.

 

For the first time in the region, waste tree boles and root balls from the highway upgrade were added to the fillets and revetment to reduce the tonnage of rock required and increase benthic complexity.

 

Nambucca Valley Landcare and the project partners also developed an innovative method to minimise water quality impacts during the construction phase of the project by protecting in-stream machine use with progressive fillet construction.

 

Weeds were efficiently removed by using the machine, reducing labour time, and the completion, the bank was planted with layers of native riparian vegetation.

 

Nambucca Shire Council erected signs at two locations explaining the rationale for the project and its success, and the project received extensive media coverage in the local and regional media

Images

 

Key facts

  • Over 400m of river restored
  • Innovative techniques used for sediment control and green waste from highway upgrade utilised
  • Strong partnership between Nambucca Valley Landcare, local and state government and private sector

Project Partners