An underground private car park beneath an apartment block in north Manly flooded on Tuesday 8 March, completely submerging an estimated 12 cars.
The car park, at 51 Pittwater Rd Manly, experienced a deluge of stormwater around 2pm, caused by rain from the East Coast Low extreme weather phenomenon affecting Sydney’s Northern Beaches.
The latest bout of torrential rains also contributed to Manly Dam overflowing and Narrabeen Lagoon breaching its banks, with the State Emergency Services (SES) issuing an Evacuation Order for Narrabeen residents.
The below-ground car park is accessible via a sloping ramp from the rear laneway, Kangaroo Lane, which was flooded by a torrent of stormwater that surged into the parking bays.
The muddy river also submerged the surrounding pavements and flowed beneath the doors of shops on Pittwater Rd, before inundating another car park beneath an apartment block in nearby Denison Lane. However, vehicles there were able to be driven out.
Michelle, a tenant at 51 Pittwater Rd and a member of the building’s Body Corporate, told Manly Observer that she heard the floodwaters cascading down the stairs from the nature reserve above Kangaroo Lane. “It sounded like a waterfall, a massive downpour of water. The car park was just overwhelmed. Plumbers were called when the [extraction] pump stopped working and they organised sandbags to prevent any more stormwater pouring in.”
Jason, a neighbour who leases one of the now-submerged parking bays, revealed he pushed a shopping trolley to Manly Beach, lined its interior with a blanket, then filled it with beach sand, which he later transferred to loads of cotton supermarket shopping bags.
Michelle tried to call emergency services when the incoming water approached the roof of the cavernous parking garage and the streets around the apartment block were flooded.
“The SES have been slammed by all the emergency callouts in these storms,” she said. “Our strata company rang them countless times for help – they were on the phone for two hours trying to get through – but none of the local SES units were available.
“Thankfully, tradies saved us. We called a company in to pump out the water and they’ve been here for hours.”
Four suction hoses attached to separate pumps were fed into the flooded carpark, slowly drawing out the water like giant straws.
Sean, from Malcolm Thompson Pumps, confirmed he’d been siphoning out the murky brown stormwater for at least two hours.
“I reckon we’ll be here for a few more hours. It’s a long waiting game until the job’s done. The floodwater came too quick and cut off the power to the water drainage pump already installed in the carpark, so we responded with our own automated pumps.
“I’ve had 16 callouts today. We have several pumps currently in action across town, sucking out floodwaters. As to where I go after here depends on how many of our pumps are still operating and whether the storm returns.”
The sign above the car park entrance read ‘Caution, maximum height 2m’. Michelle pointed to a high tide line around the 1.7m mark and revealed this was the peak the floodwaters reached before the pumps set to work. The putrid water, with unidentified objects floating in it, had decreased to about 1.2m when I arrived, but peering into the carpark I was unable to discern the rooftops of the 12 – 15 cars submerged beneath.
Jason revealed he planned not to drive to work due to the atrocious weather conditions, but was thankful he changed his mind and took his car.
He told Manly Observer, “Similar flooding happened 15 years ago, but not as bad as this. The Council need to dig holes to instal overflow tanks to catch the rainwater that pours down Raglan Street during big storms and floods the low-lying areas like Kangaroo Lane and Pittwater Road.
“There was a hole dug under Manly Oval with an overflow reservoir tank put in place, which made huge improvements in reducing stormwater around here.
“But if Council keeps building more apartments without the infrastructure to deal with floodwaters, these problems will continue and get worse.”
Michelle added, “Yes, I want to know what Northern Beaches Council are going to do to mitigate this in future? These cars submerged beneath the floodwaters here are probably all written-off, which affects the tenants’ livelihoods and insurance premiums.
“Until the Council come up with a solution these things will keep happening all over the area.”
Northern Beaches Council was contacted for comment and gave the following reply:
“Council undertakes flood studies with detailed flood modelling to determine the nature and extent of the flood problem. These are followed by Floodplain Risk Management Studies and Plans, which evaluate management options and incorporate community feedback from public exhibition to guide Council in managing the risk.
“We have a Flood Study for this area, and are finalising the Flood Risk Management Plan now. The draft Manly to Seaforth Flood Risk management Plan shows potential for above ground flood storage on Manly Oval which will reduce flooding in the Raglan/Pittwater Rd area. The report is expected to go on public exhibition later this year.
“In major events like what we have seen this week, even with the latest planning controls in place, such as the setting of new floor levels above the Flood Planning Level, existing properties will still potentially be affected in significant events.”
Northern Beaches Council CEO Ray Brownlee added:
“We welcome funding from State and Federal Governments which will help us with the clean-up task and to restore essential infrastructure, including our local roads and stormwater network…
“We are working on options to reduce the impact of flooding in these areas but in many cases and in disasters of the is scale, it is not always possible to prevent flooding for existing properties.
“With our community, we are always looking at better ways to prepare for the impact of significant storms. These kinds of conversations are going to become increasingly important if we are to make our community more resilient to these types of threats.”