Innovative drainage on Oxley Island saves grass and waterways

The Neal family on Oxley Island have developed a unique, and practical approach to managing high rainfall events after east coast lows.

Brothers Pat and James Neal manage adjacent dairy farms. The farms are situated on Oxley Island in the lower Manning River where rainfall events of 150 to 300 mm occur 1-2 times a year and floods every 5 to 10 years.

“Our biggest issue here on the coast is water logging and high rainfall events. We’ve just gone through 170 mm in two days, there’s a lot of water on all the paddocks,” Pat explains.

Surrounded by a pristine estuary, they are well aware that minimising nutrient runoff from the dairy pastures improves return and protects the environment they love.

The brothers' father Peter originally adapted the Hump and Hollow system used in Tasmania and New Zealand to provide better drainage.

Pat and James have carried on the work, constructing drains that provide better machinery access by using wider shallower drains that can carry 4-5 times the volume of traditional drains.

“We put these in with a laser grader, minimising the amount of dirt we’ve taken out of the drain, and made sure they are able to drain. There’s no big ponding either,” said James.

We’ve minimised disturbing those acid-sulfate soil which is good from an environmental perspective.”

By using lasers to guide, cut and fill, large rainfall events drain rapidly.

By removing surface runoff quickly, the water entering the estuary has less time to kill pastures and so reduces carbon and other nutrient concentrations entering the estuary.

This also gives greater confidence to delay fertilise application until after the rainfall event, reducing the risk of fertiliser loss and nutrients entering the Manning River.

Their story shows that the ingenuity of farmers can improve pastures and the environment around them.

To find more about the project and the Marine Estate Management Strategy, visit www.lls.nsw.gov.au/mems

Find out more by checking out the video on the story: Clean Coastal Catchments – Improving drainage through hump and hollow farming Video.

The Clean Coastal Catchments Project is delivered by Local Land Services through funding from the NSW Government’s Marine Estate Management Strategy.