You are here

PAHSMA – Climate Impacts

Cassy O'Connor MP

Cassy O'Connor MP  -  Tuesday, 30 November 2021

Tags: Port Arthur, Climate Change

Ms O'CONNOR - On page 22 of the annual report it talks about understanding climate change impacts across PAHSMA's area of responsibility. It points to a loan from the Climate Change office. Are you able to tell us, or are senior people from PAHSMA able to tell us the known extent of sea-level rise and other climate impacts, particularly on the Isle of Dead and a coal mine site? As we know the Isle of the Dead is subject to significant sea-level rise impacts. We know that the coal mine site is facing erosion and inundation?

Mr JAENSCH - Yes, the Isle of the Dead includes Australia's first, or Tasmania's first?

Dr ROE - The Southern Hemisphere's earliest oceanic tidal benchmark.

Mr JAENSCH - Which is significant, so a very appropriate question. I will go to Mr Roe on this one, because he's ready to go.

Ms O'CONNOR - Mr Roe, who is the star on national media on this very issue.

Dr ROE - Was I?

Ms O'CONNOR - Yes, you were, you were on the ABC -

Dr REID - Take the praise and run with it.

Dr ROE - I can run? Climate change is going to be one of our biggest issues. We are lucky that we have a record of sea-level change at Port Arthur from 1841. Since 1841 we know that mean tide-level has risen by about 15 centimetres. That has substantial impacts and will continue to do so as sea levels rise into the future. We're taking an approach which is consistent with the way we've managed the sites in the past. That is, to try to understand as best we can what those processes are and what the likely effects of those are going to be.

Since 2014 we've been working with a range of people, including researchers at UTAS, to understand specifically what the effects of sea level rise and inundation will have on the various kinds of shorelines that we have, including the Isle of the Dead and the Port Arthur Coal Mines. As you know they are complex sites, with complex environments. We were very fortunate last year to get a grant from the Tasmanian Climate Change Office and have been able to do some very specific modelling for the Port Arthur site. This situation is made a little bit more complicated because we have a creek running into the catchment with a combination of ocean swell, tide, and potentially flooding rain coming down the creek.

We now have a very good idea against the projections for sea level rise in the next 20, 50, 100 years, what that inundation is going to look like. It will be a very good baseline of information to work out what our responses can and should be. They are not simply about impacts to the obvious heritage assets like the buildings; we will be seeing increased levels of salt in the soils which is potentially, going to affect historic plantings.

We have a range of initiatives around the sites including at the Coal Mines. Beyond understanding what is going on, we are putting in place some measures to buy us additional time to work out what we can do and then to program that into budget. But we are also aware some of the impacts of climate change will just accelerate the normal processes of decay. We are quite good at doing decay; we know how to deal with that kind of stuff.

There will be an increased focus on maintenance and we will need to put more time and effort into maintaining the heritage assets, if you want to consider them that way. There will be some effects of climate change which we are not, at the moment, very well equipped to deal with. We have engaged with local, national and international colleagues to work out what kinds of responses might be appropriate or could be taken so we preserve as best as possible the heritage assets we have, but also ensure that the values of those sites are not deleteriously affected.

Ms O'CONNOR - Thank you, Dr Roe. As you are probably aware, this is a problem faced by coastal world heritage sites all over the world and Venice is spending some $6 billion on walls to keep out the water and, as we know, the Penitentiary is quite a low lying heritage asset. Has there been any losses of heritage so far - losses of grave sites, losses of significant historical features of sites?

Dr ROE - At the Coal Mines beach we have lost material. That has been happening since about 2009 partly as a combination of storm surges, but also just the day to day kind of erosion. It is slightly ironic the Coal Mines is one of the places that gets hit the hardest.

Mr JAENSCH - Do not go there.

Ms O'CONNOR - That is mother nature. She has a vindictive streak.

Dr ROE - A New York Times journalist said 'cause meet effect.'

Ms O'CONNOR - Yes.

Dr ROE - There has been some loss, but we have been very fortunate that, for example, at the Penitentiary when we did the structural stabilisation we were able to put in some new drainage systems which assist with water flow. That building was built actually with its foundations in salt water anyway, but it is the proximity of salt water now to the heritage fabric that is a challenge.

Ms O'CONNOR - Have any graves been lost, for example, from the Isle of the Dead?

Dr ROE - No.

Ms O'CONNOR - Are they threatened?

Dr ROE - The graves themselves are not threatened. The headstones, we monitor every two years for lean and any deterioration of the fabric. At the moment, they seem to be relatively stable. The last loss of graves on the island was in the 1890s when part of the island fell into the sea. Erosion issues were noted in the 1920s, 1930s.

Ms O'CONNOR - The last question on this theme and I am happy with a short answer - what sort of long term planning is being put into infrastructure ruggedising infrastructure on the site?

Dr ROE - That is something that we are just starting to work on now and that is a result of the grant that we got and the detailed report of what those impacts are likely to look like.

Ms O'CONNOR - Minister, does PAHSMA have any role in the management or guidance in the management of the Darlington site on the Maria Island World Heritage Site?

Mr JAENSCH - I think this has been explored in previous hearings and the answer at the time was that it does not have a role; it's Parks responsibility. I defer to anybody who has information -

Dr ROE - We have no direct role in managing the Darlington site.