I have seen them in the Hallett Cove Conservation Park a number of times sometimes up real close but no where else in Hallett Cove. Last one seen was on 18th January 2019 and it was a nasty young brown which coiled up for a second preparing to strike but thought better and slithered away fast as.
Hallett Cove has many open spaces with playgrounds and natural (annual) creek lines, council parks, the Conservation Park, and open paddocks. This environment lends itself to many types of fauna, including snakes and lizards. Their presence is mainly seasonal. I have never seen any snakes in the streets or in my garden, however I have seen them in the Hallett Cove Conservation Park. Blue Tongue Lizards are more prevalent, though usually harmless.