Australasia | Tasmanian updates
Above: Valley of Waitaki River in the New Zealand mountains
References
https://www.seqwater.com.au/ news/construction-commences- lake-macdonald-dam-upgrade
https://ancold.org.au/improving- safety-at-one-of-canberras-most- important-water-infrastructure- assets/
https://www.meridianenergy.
co.nz/news-and-events/spring- wind-and-rain-is-good-electricity- generation-weather
Over in Tasmania, the upgrade of Edgar Dam is boosting the local economy. According to Hydro Tasmania, with over 90% of the A$35M investment in the dam being spent on services from businesses located in Tasmania, the upgrade is now well underway and expected to be completed in the second half of 2026. The project is being carried out in partnership with Hydro Tasmania’s consulting arm Entura, with Tasmanian civil construction company Hall Earthmoving contracted to carry out the majority of upgrade works. Around 20 local businesses are also involved in the project, covering a wide range of services including earthworks, vegetation management, building materials, environmental services, civil construction and trades. Duggans, a third-generation Tasmanian family business, provided the concrete casting for the dam’s wave wall, which is made up of 178 2.5m high sections and will provide additional protection from waves that could occur during a large seismic event. Indeed, following a 4.2 magnitude earthquake in
September 2025, Hydro Tasmania confirmed there was no damage to hydropower infrastructure in the state’s southwest, with no safety concerns relating to Edgar Dam and no impact on the upgrade works.
New Zealand storage In New Zealand, after spending the winter recovering
The impact of landscape farm dams
Across Australia, private farm water storages provide critical water supplies for agricultural and domestic use in areas where reticulated supply is unavailable. In doing so, they also help support regional economies and communities. Across the Murray–Darling Basin, landscape farm dams are important sources of water and intercept runoff from their local catchment that would otherwise flow into rivers and streams. So to fully understand the water available in the Murray–Darling Basin when assessing future resources, greater information is needed about the quantity of water intercepted by these dams. Government research undertaken during 2023-24 was funded by the Murry-Darling Water and Environment Research Programme, and used remote sensing to understand how these dams have changed over time, and how they could continue to change under current and future climates. Results show that more landscape farm dams are located in the southeastern parts of the Murray–Darling Basin and since 1990, the total volume of water they could hold is estimated to have grown from 500GL to 2500GL. With climate change expected to result in higher temperatures
and lower rainfall across the basin, researchers modelled the sensitivity of streamflow to rainfall changes for the 133 catchments, finding that the mean annual runoff will reduce by approximately 33% for a 10% reduction in rainfall. These are slightly larger estimates than previous ones due to explicitly modelling the impacts of landscape farm dams. In a drier future climate, inflows into farm dams will be lower
while the use of water from farm dams is likely to be unchanged or increase which means farm dams are likely to be empty for longer periods, intercepting a greater proportion of catchment runoff. As the research shows, accounting for landscape farm dams in
hydrological modelling leads to larger declines in future runoff projections than when more traditional modelling approaches are used. Therefore, modelling the effect of landscape farm dams is considered to be critical when assessing future water resource availability in the Murray–Darling Basin. Each of the basin states in the Murray–Darling Basin has legislative control over the construction of new private water storages and so new farm dam developments may be required to be licensed as a part of water accounting and allocation frameworks. Therefore, additional water extracted by landscape farm dams may not necessarily lead to an increase in the total volume of water extracted in the basin, but rather result in a redistribution of location of extractions.
References
Farm dam in rural Victoria. Across Australia, private farm water storages provide critical water supplies
An assessment of impact of landscape farm dams and climate change on catchment runoff. CSIRO Australia’s National Science Agency.
www.csiro.au
from low inflows in early 2025, national hydro storage rose from 79% to 110% of historical average in September. And according to Meridian Energy, monthly inflows were also 181% of the historical average, lifting Waitaki storage to 91% of average. Snow storage in the Waitaki catchment, which includes Lake Pūkaki – New Zealand’s largest hydro storage lake - also now sits above average which bodes well for inflows over the upcoming weeks and months.
Meridian Chief Executive Mike Roan said the company is happy with how things are heading into summer and with snow melt ahead. “The electricity system has become very good at managing dry winters” he added, “but there are some simple ways we can lift our game to do even better.” Indeed, Transpower which operates New
Zealand’s national electricity grid, recently released a draft proposal to improve the ability of electricity generators to access water in the hard to access lower ranges of hydro lakes, known as the contingent storage, and use it for electricity generation. “Unblocking access to contingent storage to
ensure it’s available when needed would improve the security of New Zealand’s electricity system in a way that’s quicker, cheaper and cleaner than almost any other option out there,” Roan commented. “It’s unlikely that we’d actually need to access contingent storage, but knowing we can access it if needed would provide much more certainty for the entire sector.”
24 | December 2025 |
www.waterpowermagazine.com
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