Maryborough flood levee: What the council says really failed

A gate worth just a fraction of the millions spent on Maryborough’s temporary flood levee system has been blamed for flooding of businesses in the historic town. Now we can tell you how much it really cost.

The staggering cost of a gate which the council has blamed for flooding in Maryborough’s CBD has been revealed.

The penstock gate cost $150,000 – much more than the few thousands they appear to sell for online – but a lot less than the $6 million Maryborough’s flood levee system cost.

The failure of the gate allowed the rising river to rush through the stormwater system underneath CBD streets, breaching the levee designed to protect the city heart.

It lead to a mammoth Plan B effort which saw council crews work through the night with diesel pumps to prevent severe inundation.

Fraser Coast Regional Council CEO Ken Diehm this week took to social media saying he wanted to make it ‘really clear to everybody that the’ flood levee system did not fail the Maryborough CBD!

“What failed was the penstock gate that shuts off the stormwater system to prevent floodwaters travelling upstream through the stormwater pipes.

The CEO even posted a picture of the gate which some said looked like a guillotine. Others were not kind with the analogy.

A penstock gate, similar to the one which 'failed', causing major flooding issues in Maryborough's CBD

Mr Diehm said the council would not be able to find out how the gate was damaged until the flood waters receded and it could be ‘forensically examined’.

Mayor George Seymour told the Fraser Coast Chronicle on Tuesday that there would be a full investigation into the levee system and the failure of the gate.

“We are going to make sure it won’t happen again.’’

The levee wall being erected before the Maryborough flooding. Picture Robyne Cuerel

Searches online suggest they range from thousands to tens of thousands of dollars, depending on the type of gate and its capacity.

Gates made in China were priced from just a few hundred dollars.

GATE WAS A ‘PROPRIETARY PRODUCT’

In a statement to this publication the council said the gate was “a proprietary product and was installed in conjunction with a stormwater chamber. The gate costs around $150,000 at the time of construction”.

The council also dismissed any suggestions there had not been proper maintenance of the gate.

“Council undertakes regular maintenance in accordance with the manufacturer’s recommendation.”

When asked whether there any backup gates, the council said there was only one gate on the stormwater pipes.

The council also promised a full investigation.

“Council is engaging independent engineers to investigate the malfunction of the penstock gate valve.”

It also dismissed any suggestions the construction of the levee system deviated from the original design.

“Council has confidence in the flood levee system for the Maryborough CBD.

“It’s unfortunate that the penstock gate valve malfunctioned. Arrangements have been made to investigate and repair the system so it is ready to be deployed as quickly as possible.”

After floodwaters breached the levee barrier through the stormwater system on Sunday night, the council swung into action bringing about a dozen diesel powered pumping plants to remove the water.

Maryborough CBD was saved from major flooding after the use of a dozen pumps. Photo: Robyne Cuerel

More than 650mm of rain came down in 24 hours in some parts of the region.

The Mary River at Maryborough peaked at 9.96m around 6pm Sunday evening.

Major flooding starts in Maryborough as the Mary River rises. Photo: Robyne Cuerel

Cr Seymour revealed on Monday about 40 businesses in Maryborough had been flooded “with water through to the floorboards”.

“It will be a number of days before we see the end of the water. I’m really hopeful within the next week or so we’ll have businesses running.”

He said repair work would take place on the faulty penstock gate that allowed water to enter back into the stormwater system.

Flooding in Maryborough on Sunday as the Mary River rises.

Some on social media were not buying the suggestion that the levee system as a whole did not fail.

Ross Liesch posted “that gate is part of the system.....so the system failed Mr. Diehm.”

Maryborough levee at a glance

• The Maryborough levee project dates back almost a decade with a price tag of $6 million.
• The first stage included street scaping and raising Adelaide St from Sussex St to Kent St, including the intersection of Sussex and Adelaide streets.
• Stage 2 included pump and pipe work to connect the area behind the shops at the corner of Adelaide and Kent streets to the Harland car park drainage system.
• The idea was that stormwater from the CBD side of the levee would be pumped to drains in the Harland carpark to prevent flooding basements of CBD shops.

Numerous questioned why a second manually operated penstock valve was not built in as a redundancy.

Others wanted to know whether the gate was checked regularly and properly serviced.

Gary Duffy said he looked at the design of the levee in 2014 and very experienced flood engineer said the ‘system’ was doomed to fail.

“A flood (levee) is a “system” for managing water, it is not a few planks with a tarp over it.”

Flooding of the Mary River in Maryborough, – Photo Facebook David Crisafulli MP

He said the council should have used the successful Launceston flood protection system which had been tried and tested through seven floods.

But others were far more sympathetic to the council, acknowledging its efforts in scrambling to put in plan B.

Flooding of the Mary River ar Maryborough, Maryborough – Photo Facebook Kylie Taylor

Beauty consultant Sharon Hepburn said it did not matter was failed or what was damaged beforehand.

“What matters was the outcome and everybody sticking by each other and having each others back so the CBD idn‘t flood as much as it could have.

“I think the (Plan B) worked well even if it was a last minute idea, plan.

“Well done to everyone you have done Maryborough proud and this is what Maryborough community stands for.”