Category Archives: Background Information

Background Information

Paddle 2018 – Experiencing the Yarrahapinni Wetlands

Braving cool showery squalls, about 20 intrepid paddlers formed a small flotilla of kayaks and canoes to enjoy the SOMR ‘Paddle on the Macleay’, to see the results of the restoration of Yarrahapinni Wetlands.

Save Our Macleay River Inc. (SOMR) were delighted to host and organise interesting stories from stakeholders about the return of the Yarrahapinni Wetlands to its natural state as a salt-water fish-nursery with regenerating mangroves. Almost 50 years of blockage of salt water and drainage, which released frequent and extreme pollution events, resulted in frequent oyster damage and fish-kill events. The return of the Wetlands being “alive again”, was found interesting and much appreciated by these hardy paddlers.

Congregating in light rain at the Golden Hole, Elder Uncle Neville Donovan welcomed the paddlers to this significant Aboriginal area.

Oyster grower Todd Graham greeted the paddlers and described the positive effects of the natural salt water flow in the Wetlands on the health of the river. Besides using improved breeding stock in recent times, the clean water has greatly contributed to oysters maturing very quickly. Unfortunately, black water events from the adjacent Clybucca Wetlands are still occurring with lethal effects on the oysters. The restoration of the Clybucca Wetlands is eagerly awaited.

Launching the boats at the Golden Hole

When entering the wetlands, with the almost high tide carrying them, the paddlers saw salt water pouring in, two to three-metre high mangroves establishing, an abundance of pelicans, cormorants, herons and other birds feeding on fish and even the regeneration of ‘sea-grass’ on the margins of Middle Island.

Paddeling into the Wetlands

Going up into The Broadwater, the real expanse of now established fish nursery habitat unfolded. The edges and low islands are strongly tinged with the light green of regenerating mangroves. To the east with a steeper bank is the coastal rainforest, believed to be on top of a part of one the largest recorded ‘Middens’ in Australia.

Going further up, young mangroves were seen in what used to be fresh-water reed ‘side-swamps’, now covered in salt water. After about 1.5 to 2km up, the mangrove regeneration became patchy, but there was one mature mangrove that had surprisingly survived the 45 years of fresh-water!

At a distance of 2-3 km from tidal salt water in flow, the paddlers could see that significant rehabilitation in this area will take time. Small areas of ‘Salt-Marsh’ regeneration are develop ing on the edges of the old and dug ‘channel’, but the dead fresh-water vegetation looked like a bomb zone!

The intrepid paddlers stopped for a ‘lunch-break’ at the site of ‘The Scalds’, some 3.5km up the Wetlands before returning. As the name suggests, this was a large area of Acid Sulphate surface soil scalds, releasing sulphuric acid and pollutants into the Macleay River Estuary every time it dried out and rained again – destroying fish, oysters and tourism.

Relaxing at the lunch break, listening to Matt Wills from NPWNSW

During the lunch break, paddlers were interested to hear from National Parks and Wildlife Service’s Matt Wills, of the next steps in the Yarrahapinni Wetlands rehabilitation. It is planned to remove further parts of the ‘levee’, fill-in the remnant ‘flood gates’ and undertake revegetation and bank stabilisation activities; thus restoring the wetlands close to its prior culturally significant and natural state.

Returning to the Golden Hole, most participants just let their boats drift, a most peaceful experience.

It was generally agreed by the paddlers, that this was one of the few ‘success stories’ for rehabilitation of a significant wetland and a boost to the reduction in damage to the environment, economy and tourism from past practices.

Revisiting Hillgrove Mine – 30th July 2018

From 620m underground to the Tailings dams on the escarpment, SOMR representatives explored what a mine in Care & Maintenance looks like.
Guided by Peter Hosking, Care & Maintenance manager and metallurgist, with Senior Geologist Mitch Tarrant, SOMR representatives were given an overview of the current operations at Hillgrove, and a tour of Metz Mine Centre, water management facilities and Brackin’s Spur Mine.
Hillgrove Mine ceased production of Antimony in 2016, entering a phase of exploration for gold resources and Care and Maintenance.
There are four main areas of focus in Care and Maintenance; environmental management, maintaining the asset, maintaining licenses and consents for mining and exploration, and promoting future investment.
Hillgrove mine currently employs six staff, Peter, Mitch, a Fitter, an electrician, and two machinery operators. These staff must fulfil multiple roles in the management of the mine.
At various stages of the life of the mine, it has produced both gold and antimony. To be responsive to market forces, they need to be able to balance extraction, and processing of both elements.
Water management is a key process in mining, and the major cause for potential environmental concern. Hillgrove invested significant funding to provide infrastructure to allow improved water management, ventilation of the mine and exploratory drilling. 
Current dam levels are low, and the mine could manage two one in a hundred-year rain events according to the manager Peter Hosking. The investment in new membranes for the Reverse Osmosis water treatment plant, at a cost of around $75,000 is a further step in ensuring contaminated water does not enter the catchment.
Monitoring of the Tailings dams continues to follow the robust procedures in place when the mine was in production – daily visual and detailed weekly inspections, monthly water sampling, monthly piezometer recordings and three-monthly surveying to check for dam wall movement are still implemented.
SOMR would like to see Tailing Storage Facility 1, a dam commissioned in 1982, removed, the contents reprocessed, and the remaining contaminated material stored well away from the escarpment in a modern, well-engineered containment facility, with the current site revegetated. 
Maintaining the mine in care and maintenance is an ongoing expense, with no income, Hillgrove are keen to find investors to allow them to recommence operations.
If investors are not forthcoming, the company is still obliged to care for the site and to protect the river.

Activities May 2018

The last couple of weeks in May brought a flurry of activities.  First, a long expected meeting of numerous agencies concerned with the health of the Macleay River, then the Clybucca Wetlands Paddle.

Click here for a full report of the meeting. Macleay River Working Group 24th May 2018

What to Do on the Clybucca?

At an event hosted by SOMR and sponsored by North Coast Local Land Services, 55 paddlers went up the Clybucca Creek System on 26th May to explore and be informed of the environmental problems and a range of potential solutions.
A research and community engagement project is currently being undertaken on the Clybucca Floodplain, following a successful funding application for $365,000 under the NSW Department of Primary Industries (DPI) Flagship Fish Habitat Grants Program. The project, submitted by North Coast Local Land Services (LLS), will deliver a remediation strategy, complete with engineering design options to improve water management across the floodplain.
It will aim to neutralise acidic conditions across a large area of Mayes and Doughboy Swamps, improve freshwater wetland condition, and rehabilitate estuarine habitat. It will also aim to improve the drainage of productive grazing land throughout the Clybucca – Collombatti floodplain.
North Coast Local Land Services – Senior Land Services Officer Max Osborne said a key component of the project is community engagement. The Water Research Laboratory at the University of New South Wales (UNSW-WRL) has been engaged to prepare the strategy and the aim is to ensure all stakeholders’ concerns are addressed.
“Over the next 12 months, North Coast Local Land Services and UNSW-WRL will be working closely with landholders on the Clybucca floodplain, Seven Oaks Drainage Union, Kempsey Shire Council, NSW Government agencies, community groups, the Aboriginal community, industry, and academics to ensure we get the best outcomes for the region,” he said.
What’s the problem?
Over drainage of coastal wetlands has created problems with acid sulfate soils, causing sulfuric acid runoff; and has also increased the frequency and magnitude of “blackwater” events, depleting oxygen in the creeks and river after flooding. This has unfortunately had wider impacts on the estuary, including the loss of fish habitat and impacts to aquatic life, such as fish and oysters in the Lower Macleay. This impacts the environment, the local economy, recreational and commercial fishing, traditional usage and tourism.
What caused this problem?
The Clybucca sub-catchment has undergone hydrological change over time. At one time, it was covered by the sea and had slowly filled in by the sediment eroding from the upper Macleay catchment. In the late 19th century the area was a freshwater wetland. However, the marine mud (high in sulfur) lay below the wetlands sediment.
Tidal restricting barriers, flood gates and extensive drainage networks have lowered surface and groundwater levels and exposed the marine muds (naturally occurring acid sulphate soils) to oxygen—resulting in the acidification of topsoil, groundwater, in-drain water and ultimately, the Macleay estuary. (Osborne 2018)
Over-drainage has allowed flood-intolerant grass species to dominate where previously only wetland-adapted species thrived. During floods, these grasses are inundated for several days. They die and rot—depleting the floodwater of oxygen. This hypoxic (no oxygen) blackwater then drains into the Macleay estuary, which damages the aquatic ecosystem. (Osborne 2018)      Over-drainage has allowed flood-intolerant grass species to dominate where previously only wetland-adapted species thrived. During floods, these grasses are inundated for several days. They die and rot—depleting the floodwater of oxygen. This hypoxic (no oxygen) blackwater then drains into the Macleay estuary, which damages the aquatic ecosystem. (Osborne 2018)
Russell Yerbury, a former beef producer from the Clybucca Floodplain and Max Osborne from North Coast Local Land Services discussed the issues and some of the potential solutions being investigated as part of the remediation strategy project.
SOMR would like to thank Max and Russell for their commitment to improving the health of the Macleay, and for supporting the Clybucca Wetlands Paddle. We would also like to thank the participants in the paddle and encourage community to be informed and participate in this crucial decision impacting the future health of the Macleay River.
Wetlands Australia 2018 https://www.environment.gov.au/system/files/resources/b0f30409-2d92-4ec6-a57d-35e59b765be0/files/wa30-full.pdf Pg. 35 – 36 relate to the Clybucca Wetlands
Blackwater Fact Sheet http://www.environment.gov.au/system/files/resources/c6a83595-14ef-4d82-8db3-0aec0a172b64/files/cewo-blackwater-factsheet.pdf
Wetland Pasture https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0003/405696/Water-couch-growth-and-productivity.pdf

Click here for a video created by Elsinor Photography showing the Paddle.    https://www.youtube.com/watch?v=RoOsH7G3koY