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TasWater – Climate Change

Dr Rosalie Woodruff MP

Dr Rosalie Woodruff MP  -  Wednesday, 1 December 2021

Tags: TasWater, Climate Change

Dr WOODRUFF - Thank you. Dr Gumley, in the annual report there is a section, Water and Environment, and a conversation about climate change. The report says -

During 2021, TasWater commenced development of a climate change adaptation and mitigation strategy to understand how climate change might affect the way we work now and into the future.

Does TasWater have an existing climate change adaptation and mitigation strategy, or is this the commencement of the first one, or a new one?

Dr GUMLEY - We're starting the journey, and the first part of that is to work out how much carbon dioxide equivalents the whole TasWater operation is creating, and we've done quite a bit of modelling on that. If you are going to go on a journey to completely get rid of carbon dioxide out of your operations, you have to know where you're starting.

So, the first part of the work has been to measure what we are actually contributing to carbon dioxide. As it turns out, about 85 per cent of it is actually methane. With methane, it's like an exchange rate. A kilogram of methane is roughly equal to about 28 kilograms of carbon dioxide, and so when the sewerage plants create methane, that has a high carbon dioxide equivalent. We now know the whole TasWater operation produces about 57 000 tonnes of carbon dioxide equivalents a year, and that gives the board and the management team a starting point to work out how we're going to move to net zero.

Dr WOODRUFF - Great. On the face of it, this looks as though TasWater hasn't been incorporating climate changes, and I know that's not the case, so can you talk about climate change projections in terms of weather and climate projections?

Dr GUMLEY - You're more talking about rainfall and -

Dr WOODRUFF - Well, there are two parts. There's adaptation and mitigation. You talked about the mitigation. Can you talk about what you've been working on and what you're seeing and what you're projecting?

Mr BREWSTER - What we're seeing, and what we've been working on, in terms of drinking water - and everyone has seen it - is more intense rainfall, further apart, and what does that mean for the plants. So, part of the master planning at a plant level has been taking that into account - but if you remember, our key focus for the last six or seven years has been, let's just fix the drinking water. Give rid of all the 'boil water' alerts, make it so people can drink water. But as we've upgraded the plants we've said, well, at a local level, what is the impact of climate change, how much extra capacity do we need to take into account? Classic example, Bryn Estyn.

What we are now doing is saying that's great, but in terms of a more mature business, we really need to start looking at master plans across whole areas - this is for drinking water - and saying, in the next 50 years, what does that really look like? Are some of those plants going to get to the point in the next 30 years where the real water supply is no longer reliable and we need to bring in different technology? So, that's the master planning process for water.

In terms of fire, it goes into the master planning process as well. We're looking at plants that are more exposed to bushfire, we'd be at risk of losing them in a heavy bushfire and we'd have trouble defending them. In the meantime, every year what we do for all our plants is try to ensure the vegetation is clear and it's low. Longer term it may well be that some of those plants don't exist because of climate change. That's our master planning process right now.

The climate change strategy effectively works in parallel with the master planning process and feeds into that process. We've dedicated a specialist employee, pulled them out of a senior leadership role to develop this climate change strategy. It has a way to go. That's coming in conjunction with our broader environment strategy. If you think we've been focused on water and sewerage for the last eight years, to fix the basics, it's now that we need to take a step beyond that and so sewerage will be absorbed into environment.

Dr GUMLEY - The board's made a decision that how we're going will be reported at every monthly board meeting.

Dr WOODRUFF - Thank you on behalf of Tasmanians who care about that sort of action. The methane emissions are really concerning and obviously a huge challenge. It's great to see the board is putting the effort into that.

Yesterday in the Port Arthur Management Authority discussion, there was a conversation between Ms O'Connor and the board about sea level rise impacts. The Port Arthur authority has already identified a 15-centimetre increase in tidal inundation at their facility. That has already had some impacts and are projected in future. Can you talk about sea level rise and TasWater's assets, facilities, whether any are affected or are being managed? What are the projections are for costs, impacts and so on?

Mr BREWSTER - I think it is early days in terms of the plant. The master planning process will pull out whether any of the plants will ultimately need to be relocated because of seawater rise.

A bigger issue right now is the pipes and the manholes. If you get salt laden water in the pipes, in the sewer pipes, that becomes a problem for treatment and reuse. Whether that's climate change or king tides or so forth, as pipes become potentially inundated consistently, we have to move them. Salt ingress that prevents us from recycling the water is a bigger issue right now and has been in a number of our networks. So then, you have to make an assessment as to when we upgrade or replace that pipe. What do we do with the manholes? Put them all back?

At the moment, it has been more of a network problem facing us but part of the master planning exercise will be looking at all our plants and saying, are any of them at risk as a result of potential rising water levels?

Dr WOODRUFF - Thank you. For the rural water supply reductions, you referred to in your previous answer as a result of climate change and drying in certain areas, you're doing master plans for areas and a climate change strategy. Clearly, this is about the availability of water, period, either groundwater or river water. In your master planning, will you be doing this in conjunction with other bodies that are users of those water areas? Is this a coordinated effort? Obviously, TasWater is doing its own work. Can you talk about the coordination of that planning?

Mr BREWSTER - One of our general managers who, unfortunately, is unable to be here today is on the Rural Water Round Table committee with DPIPWE. We share where we're heading with them. It's early days. We also have to share our projections of where we're going with our owners and we do. That's the councils. They're a critical stakeholder. Generally, as you'll find with most of our work, we publish online. You can see our long term strategic plan and our corporate plan. We generally publish these things and invite comment as we go forward.

From our perspective, it's always going to be a pretty transparent process and we're going to involve stakeholders. Sometimes, we get it wrong and we miss people. We acknowledge that. But, generally, it's only going to work when everyone's involved. We sometimes use Tasmanian Irrigation supplies. Often, we draw from the same supply. We sometimes use their supplies or their rural water. Hydro Tasmania will have to be involved because 70 percent of our systems run off river systems often managed by them in terms of environmental flow. It is not something we can do on our own. It is not something we would intend to do on our own.

Dr WOODRUFF - The climate is changing a lot faster than we would like to see. What is TasWater's view on when that sort of work needs to be done so that we can start making decisions for the future for water allocation to master plans for all areas?

Mr BREWSTER - That's the work we're doing at the moment. We're not going to make our own assumptions. We go to BOM and other sources to determine where are the most at risk areas in our systems. That would be part of the prioritisation process. I can't tell you off the top of my head. Most of those master plans are just kicking off as we come out of this current phase of the business.

Dr WOODRUFF - A year?

Mr BREWSTER - It's probably five years' worth of work.

Dr WOODRUFF - Five years to develop the plan?

Mr BREWSTER - Not the plan. We are talking about 60 drinking water systems roughly and 110 sewage treatment plants. So, 170 systems. There is nothing else in Australia like Tasmania in terms of the number of systems and the nature of the network. It is not a simple exercise because it is not one master plan. There has to be a master plan for the Launceston area; a master plan for the Hobart area; a master plan for the Huon area. They all have different sources. A master plan for the east coast, the north west, the north east. This in not one big plan. The master planning cannot work like that. We can't do everything at once, otherwise I would need another 50 or 100 employees.

Dr WOODRUFF - It sounds like TasWater needs some support. It is not just a TasWater issue is it?

Mr BREWSTER - That is why we work with others.