The Clean Coastal Catchment (CCC) project is being funded through the NSW Government’s Marine Estate Management Strategy (MEMS) to improve water quality for Australia’s oceans, estuaries and coastal wetlands.

CCC is working with the macadamia industry to validate and understand better nutrient movement of nitrogen and phosphorous as well as sediment movement through the system.

On ground works

NSW DPI Development Officer Jeremy Bright said the first round of on-ground works funded by the Clean Coastal Catchment project has been carried out. The aim of the on-ground incentive program was to develop a drainage plan for growers, install the drainage network so that water could be diverted throughout the farm over designated grassed water courses and run out of the farm clean and free of nutrients.

A decision matrix was utilised to identify priority farms for project funding. This work was then facilitated through Kel Langfield from the North Coast Local Lands Service.

There are a few case studies that growers can look at to get a better understanding of what was involved and the process of developing a drainage plan for the farm, Mr Bright said. Some key points relating to the on-ground works are:

·      Funding for this project has allowed drainage management to occur on 50 farms across the Northern Rivers of NSW

·      On-ground initiation works has led to a further spend of $650,000 by industry to ensure completion

·      300ha of farms have addressed clean water runoff through integrated orchard management as a result of this project

·      Work on crop replacement values for individual macadamia varieties is continuing – assisting growers with more accurate calculations of nutrients.

Monitoring and demonstration sites

Two monitoring and demonstration sites have been set up and are being used to trace all pathways of nitrogen, phosphorus and sediment at a farm scale. One site is located on a typical Northern Rivers ferrosol soil type on moderate to steep slopes (>13%). The other site is more reflective of the expansion of the industry in NSW and has been setup on the NSW floodplains.

The sites’ pre-integrated orchard management intervention will collect data over the mid to long-term period (depending on future funding allocations) and will provide credible data over a series of seasons.

These two sites will then have integrated orchard management interventions which will be designed to divert water across grassed water courses and have groundcover to allow nutrients to infiltrate the soil.

“This is effectively what is occurring on the on-ground works project. It will provide a useful demonstration site to drive industry adoption of best practice water and nutrient management,” Mr Bright said.