Vancouver's outdoor pools open for the summer season this weekend, continuing a decades-long tradition of aquatic leisure in the city.

Vancouver's three remaining outdoor pools — Kitsilano, Second Beach and New Brighton — were first built in the 1930s, during the Depression, as a way to get men back to work.

Glenn Schultz, the Vancouver Park Board's supervisor of beaches and outdoor pools, is well acquainted with the transitions those pools have been through over the years; he started as a lifeguard in 1960 when he was 16-years-old.

"The pools themselves have changed radically over the years, there's no doubt about that," Schultz said.

Vancouver's Kitsilano Pool first opened July 1, 1931. It was the largest saltwater pool in North America. (Vancouver Archives)

All three pools used to draw their water straight from the sea. Schultz said park board staff would open the pools' valves during high tide to let ocean water in.

Mud sharks, octopuses

"Every once in a while you would get a mud shark in the pool which would maybe freak out people," Schultz said. "People would see this, these fins going along, and they would freak out at that."

Small octopuses would also sometimes make their way into the water, but Schultz said it was mostly seaweed that would flow in. Twice a week, staff would then empty the tanks to clean them by spraying them down with firehoses.

Occasionally, the pools shut down because the water they drew was too polluted to swim in — as is discussed in this video, originally broadcast in 1971:

The province denied summer permits for the New Brighton and Kitsilano pools because the water was too polluted. 1:57

The pools differed from their current configuration in other significant ways, Schultz explained.

They used to be mostly part of the ocean, he said, with water locked in place to give bathers a place to swim during low tide; Kitsilano Pool even had a sandy bottom until it was filled in with cement in the '60s.

And they weren't closed off like they are now, so technically people could swim in them day or night.

Also, although the water was chlorinated, by hand, Schultz said it didn't meet today's sanitation standards. The park board had to rebuild the pools so they could meet rules set out by B.C.'s Public Health Act.

The following video, originally broadcast in 1976, highlights why the park board had to spend about $6.5 million in today's dollars to renovate Kitsilano pool:

The Vancouver Park Board had to spend $1.5 million to renovate Kitsilano Pool to bring it up to modern sanitation standards 1:09

These days, Kitsilano still does draw its water from the ocean before it opens in late spring — albeit that water is now filtered and chlorinated to today's standards. The pool is then topped off with tap water throughout the season.

But Schultz said next year that will change as part of a series of renovations that will be completed with funding from the Canada 150 celebrations.

Water will once again be drawn from the ocean throughout the outdoor swimming season, eliminating the need to use potable water.

And Schultz said more changes may be coming to Vancouver's pools, outdoor and indoor, as the city collects its second round of feedback through its VanSplash Aquatics Strategy.

As part of the first round of feedback last year, the park board promised new "pop-up pools" and is looking into the potential for "natural pools," which would use plants as a natural filtration system.

"These are all the new trends that are coming today in aquatics," Schultz said.