Let's talk about off-stream storage of environmental water for the creeklands ...
Some months ago, a new off-stream water storage for Walcha was announced by local member Adam Marshall MP. It will provide Walcha with 300 ML of water which will quadruple the town’s water supply at a cost of $11m - supplied by both the State and Federal governments.
Dumaresq Dam - an “in-stream” dam
For comparison, Dumaresq Dam, which was built in 1898 as Armidale’s primary water source, holds 300 ML. Armidale’s Dumaresq Dam is an in-stream dam which recently has been reinforced to strengthen the concrete wall. It is worth noting that this dam has interrupted Dumaresq Creek’s natural flow of water from Duembandyi (Mt Duval) through Armidale for over 120 years - hence the need to explore ways of restoring ‘natural’ levels of flow along our creeklands.
The Armidale Creeklands Master Plan - approved in 2020 - argues that off-stream water storages are preferable to in-stream interventions due to the risk of damage due to flood waters and/or the potential for increasing the risks of flood damage.
Our association has long dreamed of finding source(s) of water to supplement natural environmental flows, especially during dry times. If we could find a source of water, we could help re-engineer our creeklands to have healthy flows, even during dry times - like those we are experiencing right now (winter 2023).
Increasing Flowing, healthy water supports aquatic life and helps wildlife and birds - and humans - to enjoy an even more beautiful creeklands precinct.
This story about off-stream water storages is to inform the community about our ideas to get more environmental water flowing. In preparing this story, we are grateful for the wonderful assistance of Suzannah Mitchell, the Environmental Sustainability Manager at the University of New England, who has provided some of the images below, along with some valuable explanations.
Now is such a dry time
Although we can see water in our ‘drain’, in the centre of town (Curtis Park), there is virtually no flow after such a dry winter (photo taken August 6, 2023).
Just a trickle …
On the same day as the above image (August 6, 2023), there was only a trickle flowing under the Faulkner St causeway.
We all know that Armidale has, does and will experience really dry times. During such a time, back in the 1950s …
The new University on the hill needed water for fire fighting
In the early 1950s, UNE built Lake Zot as an off-stream water storage with permission to pump water from Dumaresq Creek during flood times - to provide the University with sufficient water to fight fires.
Lake Zot is located just to the west of SportUNE facilities at the University of New England. If you haven’t seen it, it is worth a visit!
The students liked Lake Zot too …
In 1962, three intrepid explorers staked their claim as the first to navigate Lake Zot!
A regatta in Armidale?
Back in 1962, a regatta was held to celebrate the coming of a ‘lake’ - Lake Zot - to Armidale.
Settling in to the environment …
Lake Zot has settled in over many decades. Here it is, in March 2002, as a stable feature of the University and creeklands environment.
Dry times again lead to change …
By late 2018, the University’s Estate and Built Environment (EBE) Department planned to remediate Lake Zot to supplement irrigation water for the SportUNE playing fields and to improve the utilisation of the lake as a teaching, learning and research resource.
In 2019, these plans were approved by the Vice Chancellor, Annabelle Duncan, and works commenced - during Armidale’s driest year.
Lots of digging …
The scene in August 2020. The remediation involved the removal of sediment and vegetation from the lake, before the wall was lined with clay to prevent seepage.
The drainage channel directing runoff to the lake was also cleaned out and graded to optimise the flow of water.
Sediment and erosion controls were implemented both upstream of the lake and downstream, below the spillway.
Excavating and rolling along …
To ensure that the ongoing use of the lake as a teaching resource and habitat for native wildlife, experts from the School of Environmental and Rural Sciences were engaged throughout the design phase of the project.
The lake was also utilised as an integrative case study - by Dr James Turnell - for an environmental engineering unit.
The finished, compacted wall …
was completed in late October 2020, before the drought really broke.
View from above …
A birds eye view of Lake Zot in April 2021.
A sight for dry eyes …
By November 2021, the expanded lake was again at 100% capacity. After remediation, it was double its former capacity.
Saving money and the environment …
A view of the lake in December 2021. Water from the lake is now the primary source of irrigation for Sport UNE’s Consett Davis playing fields - yielding a significant saving on water expenditure for the University.
Adding environmental benefits …
In March 2022, floating wetlands were installed as a habitat refuge for wildlife …
For water birds …
After towing the wetland structure into place …
Near the edge of the lake …
in December 2022, …
The ducks finally enjoyed …
their floating wetland!
Meanwhile, the Wildlife Wetland it waiting for water …
Near Douglas St, in the east of Armidale, work on the “Weedy Wasteland to Wildlife Wetland" project, being carried out by the Armidale Urban Rivercare Group (AURG), is progressing apace along Dumaresq Creek.
This photo shows the wetland still under construction (August 6, 2023). No doubt, the health of this ‘wetland’ will benefit if more environmental water can be sourced to flow along the Dumaresq creeklands.
Can you imagine more off-stream water storages or wetlands?
Perhaps you can imagine one or more off-stream water storages? If we had one or more upstream of the city, we could regulate the flows downstream and they could also assist in flood mitigation.
If we created one or more off-stream wetlands either within the town boundary or downstream, no doubt we could pump water upstream to create additional flows.
Perhaps you can even imagine some water sports in town, or improved fishing, or a place for concerts by a ‘lake’?
Let us know your ideas in the comments. You may even decide to join us to help us develop community-endorsed Visions for our precious creeklands stream which, 125 years ago, had its natural rates of flow interrupted by the construction of Dumaresq Dam.