A drier than usual 12 months have taken a toll on New South Wales, requiring water suppliers to take urgent action. While the drought has potentially devastating effects for the state’s residents and industries, tough drought management measures being undertaken by WaterNSW are securing water supplies and stabilising the state.
According to the NSW Department of Primary Industries, 61 per cent of the state is either in drought or intense drought, while almost 39 per cent is drought affected. WaterNSW is combating the potential ramifications of these statistics with strategies such as bulk water transfers and upgrades to water infrastructure.
Bulk water transfers
Between October and December 2018, WaterNSW undertook a bulk water transfer at one of the state’s most drought affected locations. A total of 34,900 megalitres was transferred from Split Rock Dam to Keepit Dam in the Lower Namoi Valley in order to meet basic customer water demands.
Scheduled releases of water ranged from 100 megalitres per day to 1900 megalitres per day, with the peak releases occurring in late October. At the time of the transfers, Split Rock Dam was at 13.4 per cent of capacity, while Keepit Dam was at a low 10.6 per cent.
Weather conditions were carefully considered throughout the bulk water transfer process, ensuring that any changes in demand due to rainfall were factored into the future releases of water.
According to WaterNSW Executive Manager, System Operation and Asset Maintenance, Adrian Langdon, the severe drought conditions have impacted all water storages across the state, but the Namoi Valley has been in a particular need of stabilisation due to a lack of rainfall and a corresponding near absence of inflows into dam storages over the past year.
WaterNSW estimates that even with the additional water from the transfers, Keepit Dam could fall to two per cent of capacity in the near future, without receiving significant inflows. Split Rock would hold less than five per cent under the same minimal inflow scenario.
Without significant inflows, it is likely that more hard decisions will be required in the months ahead to ensure dwindling resources are allocated fairly, and with priority given to critical human needs.
“WaterNSW has been working closely with water users in the Upper and Lower Namoi to manage supply, and our management plan and the cooperation from customers has enabled us to extend supply under arguably the state’s most severe drought conditions,” Mr Langdon said.
“With government, and in collaboration with the critical water advisory panel, we are implementing strategies to extend vital supply as long as possible and sharing the hardship as fairly as we can in line with water sharing plan rules until the drought breaks.
“We will continue to monitor water resources and adapt strategies as required, and if necessary, investigate potential additional measures and actions to ensure water supplies for critical needs.”
While measures such as bulk water transfers can provide temporary relief, more permanent water management strategies are also being put in place by WaterNSW.
One such strategy is the consideration of a 12km pipeline construction from Lake Rowlands Dam to the larger WaterNSW-operated Carcoar Dam, which was recently funded for a business case by the NSW Government.
Alongside the Namoi Valley, the Lachlan Valley poses one of the greatest water security challenges in the state, being heavily impacted by the Millenium Drought and having undergone economic and environmental damage during the 2016 floods.
In 2014, the area was identified by the NSW Government as one of four priority catchments for the investment and delivery of critical water infrastructure projects over the next decade.
As a result, WaterNSW developed the Lachlan Valley Water Security Study, which explores the best options to mitigate the impacts of drought in the area, and provide ongoing water security for local communities.
According to WaterNSW Executive Manager, Asset Solutions and Delivery, Andrew George, the 12km pipeline was a key solution in the study.
“The pipeline will transfer surplus water from the Central Tablelands Water-operated Lake Rowlands Dam to the larger Carcoar Dam. This will result in more efficient storage of available water and increase operational flexibility,” Mr George said.
“The Lachlan Valley has struggled with long periods of little or no water availability and solutions identified in the Lachlan Valley Water Security Study seek to provide certainty and security for customers when it comes to water delivery.
“When developing the Lachlan Valley Water Security Study, WaterNSW looked to address two key issues: irrigation drought security and managing flood impacts.
“The study confirmed that water infrastructure solutions were needed in the Lachlan Valley, and deliverables from this study will be a major boon for the region.”
With both temporary and permanent water management methods underway, and the December announcement that the Federal Government will provide $5 billion for drought resilience and recovery, achieving a more secure water future continues to be a priority for the state.
Lauren Butler is the assistant editor for Utility Magazine. She’s based in Melbourne, Australia.