Floods

Hawkesbury Council rejects critical flood safety measure – Again!

Our community has known we have to 'Live with the River' since the time of settlement. Our relationship with the river and the inevitability of floods mean we're forever torn between the blessings of rich soils and the river's deadlier moods. My own ancestor was killed in Windsor in the flood of 1809.

But human ingenuity has given us the ability to dam rivers, and we're now told that raising Warragamba Dam by 14 meters will reduce the frequency and severity of flooding here by 75%. That it would reduce the number of homes flooded by 5000. That the damage bill would reduce by $3,000,000,000. We need that. If only we had it in March – it would have spared 500 homes and reduced the flood height by 3.5m.

The new EIS is open for public comment until the end of November. Here are all the EIS documents, and I strongly suggest you start with the Executive Summary, given that the whole EIS is 8092 pages long. Council would be completely negligent on behalf of our community, who endure the highest risk of flooding in Australia, if we didn't make a submission. Submissions run until the end of November. You should consider making a submission (look for the link in the top right corner)

I'm appalled that a majority of Councillors are so wedded to their ideology that, at last night's meeting, they voted even that down. The video above summarises what happened at the meeting.

That's right - they voted down even putting forward our own community's concerns in a document to the State Government.

I know not everyone agrees on this issue, but this is reckless and treats the 600 families whose homes were flooded out in March with contempt.

And yes, this absolutely should be an election issue.

I have of course been very, very active on the subject of flooding over this five-year term of Council: Here's a list of all my videos and motions before Council on this subject.


Make no mistake - raising Warragamba Dam will make our community safer

This morning, the opponents of flood safety in the Hawkesbury were falling upon a 'leaked' State Government report that stated something so obvious it's banal – that in the event of a major flood, the water has to go somewhere.
 
Their tortured argument says if Warragamba Dam is raised, providing a buffer against future floodwaters, then that water will need to be released progressively after the peak. This means river levels will remain elevated for a number of weeks as that release occurs - affecting water filtration and sewerage treatment plants downstream.
Scarcely surprising. Any major flood is a catastrophe with effects lasting weeks or months. There is no scenario where a major flood would not disrupt in this way.
 
Those confecting outrage even suggest that raising the dam would *worsen* the effects of flooding in the Hawkesbury – a staggeringly misleading and contemptible statement.
Such a statement is as brazen as telling people that vaccination will give them COVID. It is geared to provoke outrage. It counts on people not knowing the facts.
 
What they don't concede is that in the event of a major flood, if the dam has not been raised, those same floodwaters would hit the floodplain all at once, catastrophically. It would cause flooding to a far higher height than would otherwise be the case.
The 'Resilient Valley, Resilient Communities' document laid all this out in 2017:
In the event of a 1:100 year flood, 1000 houses would be inundated with a raised dam, instead of 5000 without. In an 1867-level flood, that's 5000 houses instead of 12,000. The severity or frequency of flooding will be reduced overall by 75%, the damage bill reduced tenfold. The flood height would be lowered by many meters.
Flood damage reduction from raising Warragamba Dam, from the 'Resilient Valley, Resilient Communities' report (2017)
 
Imagine if the floods we endured in March this year were 3-5m lower – on the order of the February 2020 floods. Many houses would have been saved. Now imagine if that flood was another 3-5m higher. Those are the margins we are talking about in choosing not to implement flood mitigation.
 
Stating that the backlog of floodwaters would be released progressively from the dam in a responsible way is so obvious as to be no admission at all. Not focusing on what *would* have happened if that buffer had not been there is irresponsible.
Opposing flood mitigation condemns thousands of houses on the floodplain to inundation when the next big flood comes, and you should remember that when you vote.

Raising awareness of the need for Hawkesbury-Nepean River Health

I was pleased to join the Federal MP for Lindsay, Melissa McIntosh as she hosted a visit to the Hawkesbury-Nepean River of the Federal Assistant Minister for the Environment, the Hon. Trevor Evans MP.

The purpose of the visit was to raise awareness of river health, a responsibility I share as the Chairman of the Hawkesbury River County Council, which covers four Council areas and much of the river from Warragamba to Wiseman's Ferry.

We have specialised plant and equipment at HRCC which is essential to keep the river free of weeds, and were disappointed when the State Government pulled some key operational funding last year - just as we completed the salvage, refurbishment and recommissioning of our giant 'Weedosaurus' harvester with a $130,000 Federal grant.

My belief is that taxpayers, to say nothing of key river user groups like Rowing Australia, representing our Olympic team training on the river for the Tokyo games, expect the tiers of government to work together co-operatively to undertake this critical and ongoing work.

Minister Evans was a thoughtful listener and we gave him a detailed account of the effects of the floods earlier this year, the temporary reprieve it has given us as it flushed the river, and the short-sightedness of forcing us to sell our plant and equipment when weeds, like grass, will inevitably grow back. This is a warning I have delivered before.

The above story appears in this week's Western Weekender, and follows earlier coverage back in February.

A Salvinia outbreak that choked the Hawkesbury River in 2004. We can't go back this.

 


The Hawkesbury Floods, March 2021

Some times it must feel like our community can't cop a trick. Devastating fires, pandemic and two floods, all within a 16 month period.

Yet again, out of the distress and destruction of property has arisen the real spirit of our local community, which has rallied magnificently. The response of our SES, Police and RFS have been truly heroic, and they deserve our respect, as do those who just help because it's the right thing to do. Neighbours help neighbours. It's the Hawkesbury way.

I tried to document the effects of and responses to flooding by visiting as many places and people as I could. These videos have apparently reached over 111,000 people on social media.

Since the waters have receded, I've been honoured to be present variously at the visits of the Governor General David Hurley, The Premier Gladys Berejiklian, Deputy Premier John Barilaro and Minister for Roads Andrew Constance.

It has also brought the need to raise Warragamba Dam back into focus.

The plan to raise the dam is about the safety of the community – the 134,000 people who live and trade on the Hawkesbury-Nepean floodplain. It isn't about development, or Sydney's drinking water supply. Nor should the debate be unduly focused on the temporary inundation of uninhabited bushland around lake Burragorang, for a week or two, once or twice a century.

The Resilient Valley, Resilient Community flood risk study released in 2017 explains 75% of our flood risk comes from the Warragamba catchment. It also points out that raising the dam would reduce the severity or frequency of bad floods by the same proportion – 75%.

Floods have already been averted or reduced by Warragamba, under certain circumstances. Severe rain events that began at the time of the early 1990s flood, when the dam was depleted to about 46% capacity, lowered the subsequent level of waters of on the floodplain by over three meters. This is the kind of 'accidental' mitigation that needs to be built into the dam permanently.

It really disappoints me that some of the commentary from people opposed to the project is so dishonest. This recent article in the Blue Mountains Gazette, and the comments of ex-Minister Bob Debus should anger everyone at risk of flooding, especially because he, like other opponents of the dam raising are usually high and dry and out of harms way. Our community in the Hawkesbury bears the brunt of this risk. I've pointed this out on many occasions.

Over the last fortnight I have stood with many people who have lost their homes and possessions because of Mr Debus' inaction in the 1990s, when there was a plan to raise the dam by 23m. The Labor government's decision not to treat this as a bipartisan issue and scotch those plans, which were shovel ready when Bob Carr was elected in 1995, is partly responsible for the damage this flood has caused.

The Canberra Times, 15-9-1995 announcing the Labor government abandoning plans to raise the dam.

Mr Debus says raising the dam won't prevent all floods. But wearing a seatbelt won't prevent all car accident fatalities. Backburning won't save every house in a bushfire. But only an idiot would argue against doing what we can.

Imagine if the present floods had been 3 meters lower as a result of being able to hold back 1000 gigalitres of that water for long enough to allow them to drain away.

When Mr Debus only notes the quarter of floods that result from rain in other tributaries, he's misleading you. And he's wrong to state that permanently lowering the dam levels by 10m is the same as raising them by 10m, because of the tapered shape of the dam. The bottom 2cm of a wine glass holds much less than the top 2cm.

And pre-emptively reducing water levels in the dam, which every armchair expert has advocated over the last fortnight would (literally) be a drop in the ocean.

The topical unit is the 'SydHarb' - A Sydney Harbour's worth of water, or about 500 gigalitres. Warragamba can hold 4 Sydharbs, and the dam raising project will add another 2. I was talking about this a decade ago. Lowering the dam to levels that would imperil Sydney's drinking water supply to create a buffer would have taken weeks, and would account for maybe 0.2-0.5 Sydharbs.

In comparison, the inflow of water resulted in a Sydharb *per day* topping the dam for 2-3 days. If we could have absorbed two days of that inflow and let it out over a week or fortnight, many of the grieving people who have lost their homes, goods or livelihoods would have been spared.

Lastly, Bob raises the debunked-a-thousand-times canard of development on the floodplain. The 1:100 flood height buildong controls will not change. Not a single square meter of land which is presently sterilised by these controls would be opened up for building in the event of raising Warragamba. And the only time any flood has exceeded the 1:100 level in the last 222 years was in 1867, showing this is a reasonable safety measure. The sad fact is that the 5,500 houses built below the 1:100 level were built before those flood height controls were implemented.

Damn you, Bob Debus, for your reckless conduct as a Minister - when you actually had a chance to do something about this, you sat on your hands.

I spoke to the media on several occasions to represent our at-risk community

Print stories: Central News (18-11-2020), ABC (27-3-2021), AAP (23-3-2021), and TV as below:

It concerns me that in each of these cases, the voice of the community at most risk is not emphasised in balancing the costs and benefits of flood mitigation.

An excellent book I have at home on the history of the construction of Warragamba Dam in the 1950s is subtitled "Thank God there were no greenies." I worry that an inability to soberly judge the necessity of flood mitigation will eventually cost lives, when a flood bigger than this one finally comes.

Nature has given us a warning. Are we wise enough to heed it?

 


Warragamba Dam in 1960

Being cavalier about community safety -- elected representatives should support Warragamba flood mitigation works

Recently, the Federal Member for Macquarie, Susan Templeman MP has made remarks opposing the raising of Warragamba Dam for flood mitigation purposes. I am disappointed that any elected representative of a floodplain like ours would oppose such a crucial safety initiative.

This has been reported in the local media:

My own statement relating to this issue is below:

 

 


What are the facts about raising Warragamba Dam?

In any given year, what are the risks of your house burning down, you getting sick, or you crashing your car?

Low, I hope. These events have a low probability, but serious consequences. So we weigh the risk, and take out insurance.

So it is with our floodplain. There have been 124 floods in the Hawkesbury-Nepean since the 1790s. We had one this year (a baby -- between 1:5 and 1:10 probability), and worse ones are a statistical inevitability.

The NSW Government 2017 report, Resilient Valley, Resilient Communities says that the damage of a bad flood could be between $5 billion and $7 billion dollars, considering that 134,000 people live and trade on the floodplain.

In a bad flood, 90,000 of those people would need to be evacuated. 12,000 homes would be inundated.

The report also says that this risk could be reduced by 75% if Warragamba Dam is raised by 15 meters, saving lives and slashing $5 billion from the damage bill. A wise investment, I think.

The cost would be that, in those rare rainfall events, a fringe of land around the current high waterline of Lake Burragorang would be subjected to temporary inundation, amounting to 0.04-0.05% of the Greater Blue Mountains World Heritage Area. Crucially, preliminary modelling suggests the most sensitive areas of the catchment, like the Kowmung River and its tributaries, would not be affected at all.

There is a lot of misinformation put about concerning the Warragamba Dam raising project. That it's a stalking horse for development on the floodplain. That it will ruin a world heritage site. That it's about increasing Sydney's water supply.

These claims are not true -- even though these issues are important. The project is about protecting life and property. I observe that most people who are opposed to the project don't live on the floodplain. They live elsewhere, high and dry. They endure no risk to themselves, their families, or property. They are entitled to their views, but have no stake in the outcome.

The attached video is an interview I did recently when I was approached by someone doing some academic research from my alma mater, the University of Sydney. I summarise many of the points I frequently make about the project, and Hawkesbury Council's attitude towards it.

I've written about this subject many times before:

https://councillorzamprogno.info/2019/07/04/interviewed-on-abc-sydney-radio-about-warragamba-dam/
https://councillorzamprogno.info/2018/04/06/hawkesbury-council-should-support-the-raising-of-warragamba-dam/
https://councillorzamprogno.info/2018/03/27/appearing-on-the-abc-news-about-raising-warragamba-dam/
https://councillorzamprogno.info/2018/04/11/425/
https://councillorzamprogno.info/a-map-of-the-hawkesbury-nepean-river-and-its-tributaries-and-catchment-boundary/

Interviewed on ABC Sydney Radio about Warragamba Dam

Overnight, former Labor politician Bob Debus addressed a gathering of UNESCO in Baku, Azerbaijan, to seek their support in opposing the raising of Warragamba Dam.

This morning, ABC Sydney Radio asked to interview me to provide a response.

Here's the audio. I repeat the argument I've made many, many, many, many, many times before.

https://soundcloud.com/nathan-zamprogno/hawkesbury-councillor-nathan-zamprogno-interviewed-on-abc-sydney-radio-about-warragamba-4jul2019

 


Hawkesbury Council fails a test of leadership on flood safety

I am disappointed that Council last night reversed the position it has held for decades, and declined to reaffirm its support for raising Warragamba Dam to provide flood mitigation to our valley, through the Notice of Motion I brought to the chamber.

As I said last night, this issue is too important for it not to have bi-partisan support.

The Mayor of the Hawkesbury, Councillor Mary Lyons-Buckett voted against the motion.

In my opinion, the Mayor's position as the chair of Council's Flood Risk Advisory Committee is now untenable. In September last year, Council ratified new terms of reference and objectives of that committee, which specifically includes advocating for the flood mitigation strategies contained in the Hawkesbury Nepean Floodplain Review Taskforce report, Resilient Valley, Resilient Communities, 'in partnership with relevant state agencies and stakeholders.'

That report's signature capital flood mitigation initiative is raising Warragamba dam.

If the Mayor is unable to support the Committee's objectives and show the leadership her predecessors offered on flood mitigation, then she cannot be its chair and she should resign from that committee.

Joint Media release - Flood Mitigation

Warragamba Dam in 1960

Hawkesbury Council should support the raising of Warragamba Dam

Warragamba Dam in 1960
Warragamba Dam in 1960

Update: The result of the motion I put to Council is recounted here.

Only last year, we commemorated the 150th anniversary of the worst flood since European settlement in the Hawkesbury district. We were reminded that, back in June 1867, an inland sea of swirling detritus 30km wide stretched from Riverstone to the foot of the Blue Mountains --  the result of only four days of rain. The survivors in Windsor inhabited a shrinking island, huddled in St Matthews Church. Wearily, they grieved over the news of the drowning of 12 members from the one family, the Eathers, barely a mile away at Cornwallis. Past the mouth of the river, the beaches from Barrenjoey to Long Reef were black with uprooted trees and bloated livestock. Of course, many of the dead were never found.

Many people are unaware that the construction of Warragamba Dam in 1960 confers little in the way of flood protection to the communities downstream. The whole capacity of the dam is for drinking water storage. In the event of a rain event, there is no "buffer" to absorb flood waters in the dam and moderate its release, reducing the frequency and severity of flooding on the floodplain.

Recognising this, there have been thwarted plans to augment Warragamba since the 1980s by raising the dam wall, and we should welcome the State Government's June 2016 commitment to a $700 million program to finally raise the dam by another 14 meters, giving it that crucial buffer. It is clear that the Hawkesbury Council, representing the community most at risk from flooding, should support this new initiative. I have been advocating and writing about this for many years.

To date, Council has not availed itself of the opportunity to express this support, and it would be timely for it to do so in the face of well intended but misguided opposition from environmentalists.

Thus, I and my fellow Liberal Councillors are bringing a Notice of Motion before the chamber next Tuesday to invite my colleagues to show their support for this measure which will protect your life and property against the rare but potentially catastrophic effects of a bad flood. I will have more to say on this soon.

ORD_APR1_2018_BP_NOM(WarragambaDam)

Appearing on the ABC News about raising Warragamba Dam

I was pleased to be interviewed by the ABC today on the proposal to raise Warragamba Dam. This project will mitigate against the frequency and severity of floods in the Hawkesbury, and will save life and property.

I'll have much more to say about this soon. Stay tuned.