Geoff Packard, left, who plays Orpheus, enters the underworld in search of his bride, Eurydice, who died on their wedding day, in “Metamorphoses.”
Geoff Packard, left, who plays Orpheus, enters the underworld in search of his bride, Eurydice, who died on their wedding day, in “Metamorphoses.”

A woman wades into the man-made pool. The water reaches her shins. You can see the bottom, you can see her feet — and then she disappears, dropping away beneath the surface, suddenly swallowed up. It’s one of several gasp-inducing moments in “Metamorphoses” at Arena Stage.

The play tells tales from classical mythology, drawn mostly from Roman poet Ovid’s 8 A.D. “Metamorphoses.” King Midas and Orpheus make appearances, as do assorted gods and more-obscure characters like cursed Erysichthon, who ate himself. Playwright and director Mary Zimmerman made her name on Broadway in 2002 with the show, which is set entirely in and around a pool of water.

“It’s this mysterious, primal, very sensual element,” Zimmerman says. “The water wasn’t an idea that came after the idea to do the show. The water was the idea.”

Each story uses the pool in new ways — it’s the ocean, it’s a river, it’s sorrow. In one scene, a young man, Phaeton, floats on an inflatable mattress and whines to his therapist about his relationship with his dad, the god Apollo.

Though Zimmerman won’t say how deep the water is — understandable, since it is a shimmering metaphor for mystery and the unknown — she says the actors don’t have to take a swim test and there’s no lifeguard on duty. She’s not worried about the actors drowning so much as shivering.

“You know what it’s like when you get out of the bathtub?” Zimmerman asks. “Even if the air is warm, you’re cold.”

She says the actors’ contracts require that the water and air be kept at precise temperatures — the water starting at about 100 degrees just before the show, and the air in the theater hovering between 72 and 76 degrees.

Since Zimmerman and set designer Dan Ostling started working on the setup more than 15 years ago, they’ve tried many fixes: a pool heater going full blast until just before the house opens, warming booths offstage where waterlogged actors could shake off the chill.

But it’s not just the heat, it’s the liquidity.

“Water does what it wants to do and you have to find ways to make that work,” Ostling says. “Ultimately, the water will win.”

Beyond the obvious — water is heavy, and the stage has to be sturdy enough to support it — it’s a hazard for actors trying not to fall on their faces. Ostling designed gridded walkways around the pool that allow the water to leak through silently (no burbling!) rather than puddling. Troughs along the exits funnel off the gallons of water that a woman in a dress who’s just emerged from a pool carries with her.

Sometimes the damp environment yields unexpected results. At one point in the play, the god Vertumnus disguises himself as a yokel, complete with a well-chewed piece of wheat straw. Years ago, after an early production of “Metamorphoses” at Chicago’s Lookingglass Theatre had run its course, “we went to take the set out,” Ostling says, “and there were wheat stalks growing underneath.”

Arena Stage, 1101 6th St. SW; through March 17, $40-$85; 202-488-3300. (Waterfront/SEU)

Elsewhere on the Water Front

The stage for Synetic Theater’s silent production of Shakespeare’s “The Tempest” is covered in four inches of water, making the most of the play’s traditional setting: The show begins with a shipwreck and takes place entirely on an island. Hydrophobes should avoid the seats in the first three rows, known as the Splash Zone. Tickets there are cheaper, though, and ponchos are thoughtfully provided.

Synetic Theater, 1800 S. Bell St., Arlington; through March 24, $15-$40. (Crystal City)