Update August 2017:
Barwon Water in conjunction with Deakin University have announced the appointment of a PhD student, Krista Bonfantine from New Mexico, who will undertake the Painkalac Reservoir Environmental Flow Project. Please click KB_intro_letter_Painkalac to read a letter from Krista introducing herself. Krista is a watershed ecologist focussed on understanding how water moves through ecosystems and on managing water for maximum ecological and social benefits.
Now that the Painkalac Reservoir no longer provides water for Aireys Inlet and Fairhaven, water releases into the Painkalac Creek can be controlled to improve the health of the Creek. The Painkalac Creek Environmental Flows Community and Agency Group (PCEFCAG), which met for the first time on 28 July 2016, will act as an advisory body to Barwon Water and the Corangamite Catchment Management Authority. There are a number of constraints but with 160 ML no longer being consumed by the town, there is the possibility of ‘pulses’ of water to increase flows to mimic normal rainfall events – the dam currently dampens these apart from when the dam is full and water spills out. This would undoubtedly have a positive impact on the health of the creek and estuary.
There has been considerable modeling undertaken already and AIDA was delighted to learn that Deakin University is to work with Barwon Water and the Corangamite Catchment Management Authority (CCMA) to measure the impact of changes in water flow. This is an exciting project and there are many questions about the best management, the impact of climate change, and long term monitoring. Perhaps one day there will be platypus once more living in the creek below the dam.
Earlier in the year (following the AIDA AGM held on 9th April 2016) an excellent forum provided AIDA members with important information about the management of the Painkalac Creek, its estuary and water flows. The presenters were Barwon Water’s Operations Manager, Shaun Cumming; the CCMA’s Strategy and Planning Manager, Jayden Woolley; and the Surf Coast Shire’s Manager of Environment and Community Safety, Rowan MacKenzie. Libby Mears moderated the session.
The forum explored what the fact that the Painkalac Reservoir will no longer be used to supply water to the townships of Aireys Inlet and Fairhaven will mean for the future recreational uses of the reservoir, management of the dam water levels, the impact on water flows down the creek, the health of the estuary and how the decision is made to open the mouth.
Representatives from Barwon Water and the CCMA explained in detail the complexity and importance of environmental flows down the creek. This includes periods of cease-to-low and low flows, high flows, bankful and overbank or flooding flows. The two authorities also explained how they are working together to agree on the management of environmental flows once the reservoir is no longer used for water supply and how these are based on environmental flow studies.
Barwon Water’s presentation included the following graph which shows just how little of the inflow into the reservoir is used for the Aireys Inlet and Fairhaven water supply. This means that while there will be more flexibility to use the reservoir to replicate environmental flows once it is no longer used for water supplies, there will only be a small increase in the volume of water released into the creek.
There was also a very interesting and detailed explanation by the Surf Coast Shire and the CCMA about the complexities of the Estuary Entrance Management Support System. This is a decision-making tool used by CCMA to help inform the Council whether to artificially open the mouth. Deakin University developed the system with technical support.