20 September 2004
Simple and smart solution to sediment
A low-cost option for riparian management is being trialled on private land in the Mahurangi catchment.
Six thousand grasses and shrubs are being planted alongside a tributary of Duck Creek in Mahurangi, Rodney, to
demonstrate a low-cost option to protect waterways from sedimentation caused by soil erosion and grazing stock.
From 20-22 September, Auckland Regional Council staff are planting the low-habitat plants either side of the creek. The
demonstration site is on private land and will be open to the rural community for field days and workshops. The site was
chosen as a pilot because of the ecological stress the Mahurangi harbour is under from sedimentation, and to support the
Mahurangi Action Plan project.
Historical research shows sediment has been entering the harbour over the last 150 years since the original forest
cover was removed. The inner Mahurangi harbour is full of silt and the outer harbour is silting up rapidly.
Scientists predict the trend can be halted and even reversed if sediment can be stopped from running off the land at
the current rate.
ARC Environmental Management Committee Chairman, Brian Smith, says the purpose of the pilot project is to find a
practical and low cost solution to reducing sediment run-off. “This is an opportunity for the ARC to work with the rural
community to identify the problems and issues they may face in fencing off and planting buffers along stream sides.”
ARC Team Leader-Rural Land Management, Glenys Kroon, says the pilot project is closely aligned to the Dairying and
Clean Streams Accord between Fonterra Dairy Cooperative, the Ministry of the Environment, Ministry of Agriculture and
Regional Councils.
“The aim of the accord is to minimise the adverse impacts of dairy farming on water quality in streams, rivers, lakes,
groundwater and wetlands. We hope that this pilot project will provide a workable example for all farmers to adopt in
the Auckland region.”
The Mahurangi Action Plan project will provide future opportunities for the community to be involved in planting days.
ENDS