The Parks Department closed the restrooms on the southern end of the park last week. A new "comfort station" won't open until next summer, the agency said.
Park regulars — some of whom have complained about rampant drug use and sexual activity in the restrooms — said the closure of the bathrooms, which the Washington Square Park blog first reported, left them scrambling for relief.
Actor Elena Burkova, 26, a Lower Manhattan resident who visits the park at least twice a week, asked directions for the nearest Starbucks to use the restroom on a recent visit to Washington Square.
"People spend the whole afternoon here and they need someplace to go," she said.
Paul "Birdman" Zig, the Village resident famous for being a perch for dozens of the city's pigeons, called the park's restrooms "gross," but he also said they were necessary as a last resort.
"Over there I don't go," said Zig, a 51-year-old retired Persian rug repairman. "It's not safe. I go to Starbucks or the McDonald's instead. But they should still be open."
Jean Shum, a Lower East Side resident and regular photographer of Washington Square Park's hawks, said the city needed to install portable toilets.
"[The Parks Department] has got to have something," she said. "Where are people supposed to go?"
Portable toilets will be made temporarily available, a Parks Department spokeswoman said. Their installation date was not immediately clear.
The new facilities will cost $6.5 million to build and are scheduled to open in "summer 2013," the spokeswoman said.
They will include men's and women's facilities with handicap access, a family bathroom and a drinking fountain.
The city will seek Leadership in Energy and Environmental Design (LEED) certification for them in recognition of their environment-friendly features.
As DNAinfo.com New York first reported, the Parks Department cut short the restrooms' hours in September amid reports that people had sex, used drugs and bathed in them.