Mr McDowell watched from his kitchen window as the mass of earth slid towards his house on August 8, 1979.
It eventually stopped about 2m from his Christie St home.
The impact of that terrifying night, 29 years ago today, had shaped his life since, Mr McDowell said.
This week he returned, as he has a handful of times before, to the spot where his house, demolished in the days after the slide, stood.
As for the many people affected, the disaster was a momentous event for Mr McDowell, and one he has struggled to move on from emotionally.
"It has been haunting me for years."
Mr McDowell's health suffered and he was on tranquillisers for several months after the event and had counselling for the shock.
He attributed some of his health issues in later life to the trauma of the landslip, and said it played a significant part in the breakdown of his marriage.
"The effect has worn off to what it was, but, man, it scared the pants off me. Twenty-nine years is a long time, but every time I go past, I can still visualise that night. It's there all the time."
Many tales emerged following the landslip, but the stories of those living at the bottom of the landslip were never heard, he said.
"We sort of got left behind, because our homes were intact and we got all our gear out."
The McDowells bought their Christie St home about three years before the landslip.
That night, Mr McDowell had put his sons, Glenn (6) and Aaron (7), to bed after returning home from visiting his wife, Emily, in hospital.
His 5-month-old daughter, Anthea, was staying with a cousin in Mosgiel.
He was standing at the kitchen bench looking out the window when he heard a crack and then, through the drizzle, saw the hillside sliding towards his home, broken buildings and trees undulating on top of the earth as if they were riding large waves on the sea.
Terrified, Mr McDowell rang 111 then grabbed his sons from their room and ran outside to warn his neighbours below him.
But as they reached what they believed was the relative safety of the other side of the street, the slip started coming around the other side of the hill, descending on Christie St.
"There was this massive pine tree, straight up and down and just riding the dirt downwards. It was really scary."
More than 70 buildings were destroyed by the landslip.
The McDowells' home and six others around them were still standing, despite buckled floors and walls.
They, too, were demolished in the weeks following the landslip.
Mr McDowell said he still harboured some resentment the family was not evacuated in the weeks before the slip.
"Civil Defence told us we were safe, that we didn't have to leave, so we thought we were OK."
Families living at the top of the hill had moved out in the days before the landslip, as cracks in the streets and the side of the hill grew bigger during a week of unrelenting drizzle.
But no-one had expected the entire hill would crumble and many had believed they would be able to return to their homes within a few days.
A commission of inquiry into the disaster concluded an unstable geological structure caused the land to slip.
