City workers will soon be filling in a cave dug into the creek bank by Sunnybrook Farm Museum, as well as dealing with a longtime, outdoor party place near Piper Creek.
Parks superintendent Trevor Poth said that in February, a bylaw officer discovered the cave, roughly three metres wide by 1.5 metres high. It was dug and used for shelter by the homeless.
“We’ve had a couple of underground structures dug through the years. It’s not super abnormal. Certainly the location of this one was a little bit interesting because it’s so completely isolated in the park,” said Poth on Friday about the cave along Piper Creek.
A pickaxe and hammer were found inside. A fire pit was located near the entrance.
Built about three metres above the current water level in the creek, the cave didn’t impact spring runoff and no slope issues were identified, he said.
This week, city workers drilled a hole from the top of the bank into the cave, located about 500 metres west of the walking trail between Kin Kanyon and Bower Place and 30 metres below the museum.
“We’re going to make it uninhabitable. We’re actually going to fill it up. We’re going to put a low-strength concrete slurry in there,” said Ron Wardner, construction and maintenance superintendent with the city’s Environmental Services Department.
“We need to make it safe. There is potential for a cave-in.”
Filling it in from the top means avoiding environmental damage to the creek from heavy equipment, he said.
Cement will be poured early next week.
Wardner said the cave is boarded up to keep people out and hold in the mix of sand and concrete until it sets.
Poth said the cave project will cost the city about $7,000 and another $200,000 will be spent on renewing about one acre of adjacent forest that has been heavily used for bush parties and by people on bikes.
“What we’re doing is reclaiming it with interpretative opportunities and some more formalized trail development through the area, as well as for re-naturalization to occur, to encourage appropriate use and discourage some of that inappropriate activity that was taking place.”
Remediation signs will be installed on paths into the area and bylaw enforcement will be stepped up.
Crews will begin their work next week.
He said enhancing public access to the area will actually help protect the forest, similar to the development of Maskepetoon Park.
Poth said people should be using the park system, but appropriately, to leave it intact for the next generation and for the health of city ecosystems.