Flow | Edition 1 | May 2016
Improving estuaries for future generations
This month's feature looks into the recent release of the Regional Estuaries Initiative. The Initiative is a $20 million Royalties for Regions funded state government program to restore the function and improve the health of six Western Australian estuaries.
Commitment to regional estuary health through new $20 million initiative
The next stage of tackling water quality issues in key regional estuaries has begun with the launch of the Regional Estuaries Initiative by Water Minister Mia Davies.
Minister Davies visited the Peel Region with Regional Development Minister Terry Redman to announce the government’s latest commitment to improve the health of six regional estuaries.
The $20 million Royalties for Regions funded package is the biggest single investment the state government has made in managing the health of our regional estuaries.
Selected estuaries are the Peel-Harvey $6 million, Leschenault $7.5 million, Hardy Inlet $2 million, Wilson Inlet $2 million, Oyster Harbour $2 million and Vasse Geographe $0.5 million.
The initiative builds on the water quality improvement work undertaken by the state government in partnership with local government, catchment groups and the community.
In the case of the Vasse, it adds to the $15 million commitment last year to the Vasse Geographe Strategy and further co-investment from regional catchment groups, local governments and industry partners.
The Department of Water’s chief estuarine scientist Malcolm Robb said the REI will build on the work done over the past 20 years while adapting management to the challenges presented today.
“In many ways REI is both a continuation and a new start,” Malcolm said.
“What we have now is an opportunity to make a difference, to continue good work and adapt our management to capitalise on what we know, what works, as well as develop new ways to do things differently.
“It’s a great opportunity to transform the way we do things and develop the next stage of actions for the next ten years.”
Malcolm says the REI model would carry on the valuable partnerships with regional catchment groups and community organisations, and would continue to push out of the water and back into the source points – land-based activities.
“Getting ahead of the planning curve is crucial to keeping up with the change in urban environments, and making a difference,” Malcolm said.
“Connecting land activity to water quality is more important than ever, as the pressure intensifies around these waterways through increased urbanisation and intensified agriculture and industry.”
Rivers of life
Iconic freshwater life revealed in survey
River assessment prepares for Whicher evaluation
An important part of sustainable water allocation is supporting the natural ecosystems that form part of the resource.
It was with this objective in mind that department staff undertook an assessment of six river systems in the South West’s Whicher area, as part of the area’s surface water allocation plan.
These systems are important sources of irrigation and drinking water.
The survey turned up a large variety of the aquatic life our South West rivers are known and loved for.
Some of the region’s most iconic lifeforms came out from under rocks and logs and showed their faces to become part of the head count.
Endemic freshwater crustaceans including the critically endangered Hairy Marron found only in the Margaret River, the ancient eel-like Pouched Lamprey that uses its primitive suckers to crawl back upstream to breed; native Balstons Pygmy Perch and Mud Minnows that are listed as threatened and a myriad of aquatic life turned up in the traps and nets set strategically by the river scientists at select locations in the area, providing a snapshot of biodiversity.
River science manager for the department Dr Tim Storer said the survey followed a method of river health assessment developed here in WA, tailored for local conditions.
“The South West Index of River Condition (SWIRC) provides a scorecard that allows us to compare systems across the South West of the State,” Tim said.
Senior scientific officer Gill White said getting into the rivers to assess the fish, macroinvertebrates, vegetation, habitat and water quality is one of the most rewarding parts of her job as a water scientist with the department.
“It’s a privilege to get up close and personal with these aquatic life-forms, some which only live in this part of the world. Our team have the fortune of being able to collect our own raw data, analyse it and provide recommendations that feed into the management of the state’s precious water resources”.
South West Senior scientific officer Mike Braimbridge said the surveys were a critical part of fine tuning our management of surface water in the South West.
“They confirm whether the water sharing rules between providing water for water users and the environment are right or whether we need to adjust them.”
Water for the Mid West
Ancient buried rivers uncovered as future water sources
Stakeholders get sneak peak of ancient buried rivers
Regional stakeholders were recently given a premiere in Geraldton of three-dimensional images of buried waterways that lie beneath the East Murchison and have the potential to become significant water sources for the arid zone of the Mid West.
The images they were shown were built through a collaboration between the Department of Water and CSIRO as part of the state government's Royalties for Regions $1.9 million East Murchison groundwater investigation.
Building the images first required flying an aerial electromagnetic survey over 52 000 km2 of palaeochannels – the largest such exercise of its kind in WA water history.
This data was merged with geological and groundwater quality information from more than 2000 existing boreholes across the project area, and processed and built into a visualisation.
“To be able to go back to the community with the results of our work is very satisfying,” lead hydrogeologist Scott Macaulay said.
“While the science we are using is cutting edge and we are very proud of that, at the end of the day this is about locating water that can be of use to the communities and businesses that live and work in this region where there is very marginal rainfall.”
The identification of suitable groundwater supplies in the East Murchison area would strengthen the region's agriculture and mining sectors and support continued regional growth.
The Murchison palaeochannels were carved into the landscape around 2.5 million years ago. At this time of history, a long period of global cooling was ending and the Quaternary period of the earth’s history was starting - transforming the earth’s climate and landscape with millions of years dominated by ice ages until around 10,000 years ago.
The ancient riverbed sands which fill the palaeochannels often still hold water, and can be one of the few reliable sources of groundwater within the arid zones of the state.
While small volumes of groundwater are already accessed by pastoral and mining industries, groundwater is relatively sparse in this area of the state and the department is just beginning to build knowledge of the palaeochannel aquifers.
The new mapping of these ancient rivers of the East Murchison shows the palaeochannels vary in depth but are significantly deeper than other palaeochannel systems in regional WA.
“This new information provides industry and government information about the make-up of the region's palaeochannel aquifers and the location, quantity and quality of water resources, as well as the groundwater dependant ecosystems, to assist water and land use management decisions.
“By making this information available we provide additional opportunities for pastoral and agricultural developments, as well as more secure town water supplies.”
Work continues to quantify the vast resources of the West Canning Basin
Resource potential revealed in West Canning
From water users to global climate scientists, there has been a lot of interest in the work by the Department of Water in the West Canning Basin.
The West Canning Basin is located 100 km east of Port Hedland and about 300 km south-west of Broome. It is part of one of the biggest sedimentary basins in Australia - the Canning Basin.
It is also the focus of a four-year, $12.5 million Royalties for Regions-funded Pilbara Water discovery project that began in 2012.
Recently the Department of Water has conducted the most comprehensive test ever of the West Canning basin’s artesian Wallal Sandstone aquifer, part of the Sandfire area north-east of Port Hedland.
The test has significantly improved our understanding of this groundwater system.
During the 66-day pump test an expert team of scientists closely monitored artesian flow and pressure around the clock at ten sites across the West Canning Basin investigation area.
The test was designed to simulate long-term use of the groundwater resource and results will now be combined with data from exploratory drilling and airborne electromagnetic surveys to build a complex groundwater model of the system.
“We now know that the aquifer can discharge groundwater at up to 210 litres per second,” hydrogeologist Rob Milton said.
“Drawdown impacts and pressure reductions were measured up to 20 km from the test bore, and when we finished the aquifer test, water levels across the test area recovered almost immediately.
“These results tell us that the aquifer in the area is very homogeneous and highly transmissive. This means large volumes of water can be discharged quickly and over an extended period.”
As a result of the first stage of this investigation, and other investigations by Water Corporation and industry, the Department of Water increased the allocation limit in the West Canning Basin allocation area in 2014 by 20 GL/y to 50GL/y.
These recent more detailed investigations will inform whether and how a further 50 GL/yr of sustainable good quality water could be proved up in the Sandfire area.
The test results were further welcomed in the context of the interest in the capacity of the West Canning Basin as a water resource to provide new groundwater for allocation to towns, industry and agriculture.
In July last year, a spectre of doubt was cast over the potential for the West Canning to provide new groundwater for allocation when NASA published a report listing it as one of the world’s most depleted aquifer systems. However, the availability of the Department of Water’s more detailed data and comprehensive science shows this is not the case.
“The Canning Basin is a massive system with aquifers recharged through rainfall and cyclonic events and groundwater levels experience fluctuations of varying degrees across the system over time periods between recharge events,” Rob said.
“Department of Water scientists have noted that the NASA results are affected by the declining pattern of cyclones over the ten year study period. The time period over which NASA conducted its GRACE survey does not provide a sufficient data-set to establish a proper relationship between rainfall and aquifer recharge, nor to assess long term aquifer performance. This view is supported by the Commonwealth Scientific and Industrial Research Organisation (CSIRO).”
Breath of fresh air
A new oxygenation plant is breathing life into the Vasse
New plant gets to work on Vasse oxygen levels
There used to be a time in the wee hours of the night when Department of Water district manager Dr Kath Lynch found it difficult to sleep.
Thanks to a new oxygenation plant installed near the Vasse floodgates, Dr Lynch no longer has this problem.
Now, before you leap to conclusions, the sleeplessness was not a case of being unable to leave her work in the office, rather, because of the scientific fact that oxygen levels in the local waters are typically at their lowest around 3am in the morning.
Low dissolved oxygen is one of the main causes of aquatic stress that can lead to mass fish deaths such as those experienced in the Vasse in 2013 and 2014.
Quite literally, it’s the worst fears for the dedicated water managers protecting the qualities of this waterway, to wake up to a system crash, and thousands of dead fish, and angry residents.
Kath is a lead water scientist involved in the government led Vasse Geographe Strategy, and is passionate about developing science-based management actions that support the waterways’ health.
“This year it’s hard to describe the difference but from a management perspective, knowing that this machine is coming on and boosting dissolved oxygen, quite literally helps me sleep at night,” Kath says.
“Last year when the dissolved oxygen levels declined the main management action we had to reduce a fish kill was to open the fish gate on the surge barrier.
“This year we have the operation of the plant automatically linked to data loggers that trigger the plant to come to life when dissolved oxygen goes below a set level.”
Water quality data including dissolved oxygen levels at the floodgates is now available online to the community via the Department of Water and can be viewed through a web browser.
The Department of Water has made the information live to assist remote monitoring by scientists as well as to provide information to the community.
“Hopefully the community is also sleeping easier at night knowing we have this in place,” Kath says.
The next stage is to find out how far the benefits from the oxygenation permeate into the system.
“We are busy working out how far the plant oxygenates the channel in front of the Vasse surge barrier,” Kath says.
This is one of many actions the government is leading as part of the Vasse Geographe Strategy.