Simple Solution.

The Hasidic community that has religious restrictions against men and women mixing in public places should simply fundraise and finance their own pool, privately.  Then, they could set their own rules, religious-based or otherwise. 

We've been here before, afterall.

When Catholic parents did not like the educations their children were receiving in public schools because they preferred to teach their children their own religious values during school hours, they went private.  After 20 years of discrimination against boys and men who do not share their faith, why should the Hasidic community be allowed to impose their religious restrictions on others?

For 20 years, the center has blocked off female-only hours to accommodate the area’s large Hasidic population. The pool has no male-only hours, and some Hasidic men swim during the hours that are open to all genders. An anonymous complaint was lodged recently with the city’s Human Rights Commission, which sent a notice to the parks department this spring saying that the policy might violate a city law barring gender discrimination in public accommodations.

...

Women’s hours are held three times a week during the summer months. At 10 a.m. on Wednesday, a lifeguard’s whistle squealed. “Everybody out,” she said.

In fact, the message was just for the men. The women’s hours would begin at 10:30 a.m. (There was a half-hour break in between.) Swimming freestyle in the lane marked “Slow,” Tim Main stopped and gripped the pool ladder, peeling off his goggles. He turned to the nearest pool-goer and threw up his hands. “I hope this goes all the way to the Supreme Court,” he said before climbing out and shaking off.

“The idea of being kicked out from swimming time isn’t really the issue,” Mr. Main, 56, said later, now dry and standing on Bedford Avenue in front of the brick pool house. “It’s the creeping of religious stricture into public space.”

...
Gripping a yellow pool noodle, Miriam Kahn, 77, treaded water in a pink dress and a pink ruffled swimming cap on Wednesday morning. “In our religion, women don’t go to no beach, don’t go to no movies, nothing,” she said in a thick Israeli accent. “Can’t we have this something?”

Sure you can, Mrs. Kahn.
But you cannot do it while discriminating on the public dime.

Take a lesson from the Catholics:  privatize if you feel so strongly about gender roles, segregation and modesty.  But please understand:  you do not have the power in America to impose your religious values on others in public spaces.

Too bad the Supreme Court got that ruling wrong about publicly imposing Christian prayers at the start of public meetings... That too will change one day, sooner rather than later, I hope.  Nothing prevents politicians and the public from gathering together before such meetings to pray privately, but that should not be mandatorily imposed on others either, who might or might not share the prayer leader's faith and religious practices.

That's America, one nation indivisible with liberty and justice for all.  God knows where he stands in our hearts and souls, and he'd much rather be present in our actions rather than be used to divisively favor this group or that.