(Not) 50 years of water security

Readers will have noticed by now how much I love the gems that we get from Mayor Pennisi on Emu Swamp Dam.  I so enjoyed the most recent quote, that Emu Swamp Dam would “be a solution for 50 years”, that I want to go back to it again.

Mayor Pennisi’s 50 years takes us to 2070, and in fact we’re lucky enough to have some insight of what the dam’s reliability might be like then.  GBIP’s own modelling (the updated Badu report) stated that:

“the effect of a dry climate change scenario as at 2070 might [be] to reduce long-term monthly reliability to just 65.1%”.

I don’t know about you, but I don’t like the sound of a dam with 65% reliability being the one that is going to save me in a drought.

The State government presentation to Council in November 2020 had “no allowance for climate change effects”.  This is the presentation which said that Emu Swamp Dam would have been functionally empty during the last drought.  So if the State government’s recent modelling had no allowance for climate change, then how can the Mayor or the Council suggest that Emu Swamp Dam offers any benefit in a drought scenario, let alone for the next 50 years? 

The updated Badu report further stated that whether the project could achieve its long-term monthly reliability of 90% was contingent upon two additional things.

Firstly, SDRC’s annual water allocations in Storm King Dam had to be reduced by 400ML.  THIS IS NOT SDRC’S CURRENT POSITION.  SDRC proposes to transfer 450 ML to Emu Swamp Dam by selling this allocation to GBIP, but has already obtained from the State an additional 250 ML for Storm King Dam.  This would mean a net reduction of only 200 ML.  Bearing in mind both dams are in the same catchment will this mean that Emu Swamp Dam will not be able to meet its reliability target at all?

Secondly, GBIP had to purchase and hold an additional 2,300 ML of upstream allocations, on top of the 3,900 ML it needs for the dam.  This on current average market rates would cost irrigators (including Council) $6.9m more than the current budget.  Council’s share of this would be over $1m.  GBIP clearly flags in its Water Sales Documents that further allocations need to be acquired to improve the dam’s reliability, and the cost of this would be added to its annual charges. 

50 years?  To quote Darryl Kerrigan in The Castle “Tell him he’s dreaming”.