Like so many other black institutions created out of necessity, the Nile was founded in 1958 by African Americans who were prohibited from joining the Yeadon Swim Club.
Blissfully, their children never knew the difference.
"This was camp for us," says Marc Alexander, 46, a television screenwriter and producer who flew in from Los Angeles for the reunion. "We used to play basketball, sweat, dive into the pool, go home, eat dinner, and come back and do the same thing."
Yet, while the dozens of Yeadonites reconnected with their past under fickle skies Saturday, they also used the occasion to brainstorm about the Nile's uncertain future, which many of the members didn't know about.
For three years now, the Nile has been saddled with a delinquent tax bill of close to $200,000 that threatens its survival. The club filed for bankruptcy protection to avoid a threatened tax sale in 2010, and is working out a payment plan with the William Penn School District, its biggest creditor, said past president Darrell Henderson.
Yet with membership at an all-time low of only 70 families, Nile alumni - many of them successful professionals - wondered how they could get the needed funds.
"We need to at least double our membership to feel good, not great, about our situation," said president Barbara Willis, 58. The Nile's one-time membership fee is $475, with yearly dues ranging from $175 to $275, she says.
She noted that the club has white and Latino members as well.
"We don't deny anyone," she said.
Member Tammi Forbes suggested soliciting memberships from past members. After all, back in the day, the Nile boasted a membership of over 500 people.
"With so many of our people doing such great things since they left, they need to just buy a membership," said Forbes, an elementary teacher who lives in Sharon Hill. "There have been days when my children have been the only ones at the pool. . . . If you see people here, it makes you want to come."
But if people shell out hundreds of dollars a year for a membership, the club has to offer them more, says Kia Puriefoy, whose grandparents, Carson and Betty Puriefoy, were among the founders.
"These buildings haven't been refurbished in God knows when," said Puriefoy, 47, as she looked around the pleasant, but worn, facility. "They at least need to build a snack bar."
"The grounds are wonderful," she added, "but you need something on them."
A dedicated group of volunteers works year-round to keep up the grounds, which include a basketball court, main pool and kiddie pool, and a covered pavilion area where patrons can sit and eat. Past president Henderson volunteers as the pool operator and works with lifeguards.
'This is my history'
If the Nile leaves, so will a big piece of history.
The eight founders who went door to door selling $250 bonds to buy the Nile's 4.5 acres of land probably never realized it would still be standing as the first African American-owned swim club in the nation.
"This is me. This is my history," says Lisa Nelson Haynes, 46, whose grandparents were original members of the Nile. "This teaches us that we came from something and can do for ourselves."
Besides self-sufficiency, the Nile single-handedly taught generations of children how to swim - still an important task given that black children are three times more likely to be unable to swim than white kids, due, in part, to past discrimination by public pools.
"This pool means everything. It's a sense of pride," said 70-year-old Roosevelt Harper of Mount Airy, a 25-year member who lived across the street from the facility in the '70s. "Having three kids, it hurt for me to pay the dues, but I knew I had to do it, even when I couldn't afford it. We have to keep this going."
As irony would have it, the Yeadon Swim Club, which barred African Americans all those years ago, is gone. Drowned, like so many other private pools in the area, by delinquent taxes.
Now that the conversation has started, members have vowed to do something.
"We're the last ones standing," Willis said. "We need to keep it going."
Contact Annette John-Hall at 215-854-4986, Ajohnhall@phillynews.com or on Twitter @Annettejh.