Standing on a knee-deep embankment in Kikuyu grass, Stephen Osborn shows off his alluvial plains to his potato crop. He expects to get 12 tonnes of potatoes per acre this year.
Stephen and his twin brother Roger are vegetable growers from Pitnacree, a very fertile agricultural area surrounded by the growing town of Maitland in the Hunter Valley of New South Wales.
The Osborn family have grown produce on their 120-hectare (300-acre) farm for the past 80 years, but now they fear potential changes to the water-sharing rules will shut their business down.
These fears were triggered because the 10-year water-sharing plan that governs irrigators like the Osborn is coming to an end, with a new project in the works.
In preparation for its release, the New South Wales Department of Planning, Industry and Environment (DPIE) water division informed irrigators of a proposed shutdown rule pumping that could replace the water sharing plan.
The current plan covers a large area, stretching from the Liverpool Ranges to the Newcastle coastline.
Water managed under the current plan provides flow to Ramsar-listed Hunter Estuary wetlands. Concerns about the environmental waters reaching these wetlands prompted the DPIE to introduce new regulations to protect environmental flows.
For the Hunter Estuary, the environmental flow begins at the top of the watershed, flows through tidal pools, and eventually enters wetlands, and then moves toward the ocean. In the replacement plan, the DPIE seeks to put in place environmental flow rules to ensure that enough water flows through the tidal basin to estuaries during periods of drought.
Environmental flow rules normally take the form of pumping stops. In tidal water sources, where water levels are based on the tides, the rules for stopping pumping are determined by the salinity levels. These levels are measured by the electrical conductivity (EC) of the water.
In September of this year, the DPIE proposed a stop pumping rule when the EC at Green Rocks, Duckenfield near Maitland, reaches 4000 CE, for all irrigators in the Hunter Tidal Basin.
A review of this proposal showed that had this decision to stop pumping been passed in 2019, no pumping throughout the Hunter Tidal Basin would have been allowed for 260 days per year.
Under the current plan, there are three sources of tidal water in the Hunter Estuary – the Wallis Creek, the Paterson River, and the Hunter River tidal pools. Currently, there are 204 water licenses for the three tidal water basins.
Tidal pools are the areas of fresh water at the top of an estuary, which are affected by both fresh and salt water. They are unique because the amount of water stays the same but the salinity of the water fluctuates considerably.
Irrigator Julia Wokes says that although her property is tidal, it is not saline.
“I’m further upstream, so having a single-number-based stop pumping rule negates the historical use of the river and the businesses that depend on it.”
Wokes has irrigated from the Paterson Tidal Basin for the past 16 years, which has supported his cattle ranching and fern nursery.
Wokes bemoans the potential loss of productivity and fears that the highly productive Hunter lands could be “sterilized” without water.
“You will lose not only profitability, but also agricultural expertise, which is inextricably linked to the land,” says Wokes.
Farmer and coffee owner Jesse Clarke runs the Phoenix Park Farm, located east of Maitland on the fertile floodplains of the Hunter River. Offering a model of a paddock on the plate, Clarke worries the decision to stop pumping could have a huge impact on his current farm operation.
Adopting a form of agrotourism, Clarke invites her patrons to the farm, where they can shop for weekly chemical-free boxes of vegetables and access the farm’s Hutch Cafe.
“With the veg boxes and the coffee management, having a variety of products is paramount, but without water security it will be almost impossible and we will have to cut our expenses,” said Clarke.
Reducing for Clarke would mean producing fewer vegetables and resorting to simply growing alfalfa for hay, a result that would limit the availability of locally grown produce within the Maitland community.
Describing the decision to stop pumping as a “one size fits all,” Dr Cameron Archer, former principal of Tocal Agricultural College in Paterson, questioned the logic behind the proposal.
He says in the past, growers have “self-regulated because no one is going to put saline water on their crops or pastures, they’ll just stop pumping based on the salinity levels at their pump.”
Tocal College offers hands-on learning facilities in agriculture, conservation and land management on its 2,150-hectare (5,350-acre) campus and irrigates 80 to 120 hectares (200 to 300 acres) from from the Paterson Tidal Basin.
“[Without] With the confidence to invest in irrigation, Tocal will see a decline in farm income and a decline in the efficiency of the farm as a place of student education, ”said Archer.
According to him, “improvements should be made in the measurement and management of water, because an arbitrary stop of the pumping will not produce better results for all the users”.
Dave Miller, a New South Wales-based water sharing consultant, also says that “meters as well as extraction limits should be fundamental to all water sharing plans.”
In 2009, when the current water sharing plan was established, it included an extraction limit, which was supposed to be the sustainable limit for water extraction from unregulated river systems.
Miller says such limits are “meaningless, because the pumping of unregulated rivers is often not measured, so no one really has a clue how much water is being withdrawn.”
He goes on to explain that the problem has been apparent for over 20 years.
“Until metering becomes mandatory for all unregulated river water users, extraction limits cannot be properly implemented,” Miller said.
New counting rules will come into effect for coastal regions on December 1, 2023.
The Osborn family has been aberrant in this area, supporting the use of the meter for 10 years. The family installed meters on all of their pumps, around the time the current water sharing plan was enacted.
“We read the meters every year and send the data to the water utility, so we all know exactly how much water we are using,” says Stephen Osborn.
At the height of the 2019-20 drought, they used 330 of their 800 megalitre water license.
For many years, the Osborn people have increased the carbon level in their soils in order to improve water retention. They plant green manure crops of peas, oats and sorghum fodder to increase organic matter, and therefore soil carbon.
The Osborn say the rich alluvial plains are vital in providing food for the growing Hunter population. They also explain that the self-regulation of any tidal basin is central, especially when it comes to vegetable production, as they are sensitive to salinity.
Developing a better understanding of how the Hunter Estuary will function in the future is vitally important from an environmental perspective, as well as to all other water users.
Dr William Glamore, associate professor at the Water Research Laboratory at UNSW, has spent the past 15 years with his team working on a computer simulation model that uses data to see how water moves through the Hunter Estuary. .
Modeling has observed that parts of the estuary are extremely degraded and any additional stress on the river system will likely worsen the situation.
“We have to keep nutrients from going out of the system, stop erosion and try to use nature-based solutions,” says Glamore.
Guardian Australia has contacted the office of NSW Minister of Water Melinda Pavey to ask why a location in the Hunter Tidal Basin was selected as the trigger for the stop pumping rule, and so other tidal basins in coastal watersheds were also likely to see the same. rules in their replacement plans. No response was given.
The draft replacement plan is expected in December, with the date of the new water sharing plan being proposed for July 2022. Once published under the Water Management Act 2000, the plans have an effect. 10-year legal.