Most of the big brother–little brother act between New York City and Philadelphia is all in good fun. Eagles versus Giants, Mets versus Phillies, international metropolis versus city of neighborhoods — regardless of who wins, the sun still rises the next day.
But start scratching around about the fact that these two cities share the same source of water in a rapidly warming world, and folks in the know start to get fidgety.
New York City drinks from the top of the Delaware River, where reservoirs constructed in its headwaters in upstate New York funnel hundreds of millions of gallons a day to the city. The water that’s left turns into a proper river and heads south, where New Jersey, Pennsylvania and Delaware take their cuts before the river empties into Delaware Bay.
These states along the river’s path engaged in legal warfare several times in the past century, twice taking their case to the U.S. Supreme Court to decide who gets what. Since then, a mostly stable peace has held as collaborative efforts sprang up to manage the river. Few residents of either New York City or Philadelphia likely think much about the security of their drinking water, if they even realize they share the same source.
But Howard Neukrug, executive director of The Water Center at the University of Pennsylvania and former commissioner of the Philadelphia Water Department (PWD), is one of those people. And he’s keeping one nervous eye on what could happen should an unprecedented drought test the relationship between the two metropolises in the decades ahead.
“What’s really nice right now is there is a [collaborative] process … . But that’s because we’re not in trouble,” Neukrug says. “If you were the water commissioner of New York City, and there was some kind of crazy drought, and you only had enough water for New York City, would you still make releases into the Delaware?”
Neukrug isn’t the only one thinking about such scenarios. Current staff at PWD, as well as counterparts with the Delaware River Basin Commission (DRBC), an interstate agency overseeing the watershed, are racing to model what could happen as sea level rise pushes salty water further up the Delaware River, toward Philadelphia’s main Baxter Drinking Water Treatment Plant in Torresdale.
Exacerbated by drought conditions, the saltiness of the water could theoretically threaten the intake, impacting the quality of water, requiring expensive treatment fixes, or — in the worst-case scenario — making the water unfit to drink.
With memories of the Baxter plant shutdown fresh after this year’s chemical spill in the Delaware set off a chaotic rush for bottled water among Philadelphians, the prospect takes on new weight. In an interview with Grid, PWD staff at first chose their words carefully, emphasizing the collaborative relationship and respect they have for their counterparts in New York City.
But when asked about the fact that New York is angling to ease up requirements for the amount of water it sends south, especially with the risk of a future drought looming, PWD spokesperson Brian Rademaekers didn’t hide the fact that Philly is prepared to once again go to battle if needed.
“We would not accept a less favorable outcome. It would go to the Supreme Court,” Rademaekers says. “There’s no way that we would accept New York getting drinking water and us not.”
Going with the flow
Water is wet, but the details of how it is managed in the Delaware River are undeniably dry. Understanding how the four adjacent states, federal government and multitude of public and private stakeholders split up the river’s water requires a deep dive into abstruse bureaucracy and policies.
And yet, there is so much riding on it. Not only the threat of a severe future drought, but a multitude of present-day concerns: public recreation on the river, the health of endangered flora and fauna, and impacts to a variety of industries that use the river. Decisions have repercussions near and far, from Philadelphians who pay for water treatment through their utility bills to people in the far corners of the watershed who paddleboard and fish at reservoirs.
The rules of the river have built up through time like a layer cake. In the early 20th century, New York began building vast reservoirs capable of holding more than 200 billion gallons of Delaware River water. That triggered New Jersey v. New York, a legal case in which the U.S. Supreme Court established “flow rates” in the Delaware River at Port Jervis, New York and Trenton to ensure enough water was reaching downstream users.
When New York City began building even more reservoirs to quench the thirst of its growing population in the middle of the century, a second water war between the states ended up back before the court. A 1954 decision allotted New York City and New Jersey 800 million gallons and 100 million gallons a day, respectively, shuffled the flow rates for downstream users and set up a program housed by the U.S. Geological Survey to try to ensure the parties played nice in the future.
Soon after came the DRBC, a novel entity established during the Kennedy administration between the four states and the federal government to decide how to not only manage water resources but also combat rampant pollution and other issues.
Eventually, the agencies moved away from hard-and-fast rules and developed a “flexible flow management program” that allows variability to the management of reservoirs as long as flow rates at Trenton and Montague, New York, remain adequate, particularly in times of drought.
To date, this diplomatic system has held. Conditions have never since deteriorated back to those under the “drought of record” in the 1960s, when New York reservoirs stopped releasing water, downstream river flows fell dangerously below their targets and the salt line threatened Philadelphia.
But there is growing concern that the status quo is becoming obsolete, potentially threatening the peace between the states.
Getting salty
Want to gauge the health of this entire Delaware River apparatus at any given moment?
Check the current location of the salt front, where the freshwater of the Delaware River heading south meets Atlantic seawater pushing north in a brackish clash.
Historically, this mixing zone hangs out somewhere near Wilmington. During periods of drought it begins creeping up the river, where it can damage ecosystems, push into aquifers and harm or incapacitate industrial intakes and processes. The further the salt line pushes up, the tighter the tension between water users throughout the basin. New York and other upstream users must release more water to push seawater back down, risking their own supplies and the recreational enjoyment of places like Blue Marsh Lake in Berks County.
In a theoretical worst-case scenario, the entire system just runs out of slack and drinking water supplies go belly up. This has never happened, but there was a close call during the 1960s drought, when the salt line traveled about 30 miles upstream and stopped just south of the Betsy Ross Bridge, threatening the Baxter plant.
But Amy Shallcross, manager of water resource operations at the DRBC, says looking backward is no longer the way to protect the system. It’s the future we need to be worried about.
“What was the worst drought before the worst drought?” Shallcross asks. “You can always have a worse drought.”
Therein lies the key question: how much worse?
Shallcross says there are two new threats. The first is sea level rise, already well underway, which pushes seawater further up the Delaware River, eating away at the effectiveness of status quo management. The second is changes to rainfall patterns. Typically, it’s heavy rainstorms and flooding that cause havoc in the watershed. But climate scientists also predict a future world of competing extremes, where drought conditions are also intensified.
Uncertainty is a key challenge in planning for both problems. Just how bad will climate change get? How will that impact conditions on the ground in the Delaware Valley? What measures would be effective in combating them?
The DRBC members and New York City are planning to update the flexible flow management program in 2028, a potentially crucial political moment in protecting the future of the watershed against the changing climate. Shallcross says her team at the DRBC is working to model future conditions and present actionable data ahead of those decisions.
Kelly Anderson, director of the Office of Watersheds at PWD, says Philly has also beefed up its own scientific staff and modeling programs. It’s a work in progress, and although Anderson says results already indicate current flow management plans would protect Philly water from a severe drought crisis for the next decade, the longer term threats are undetermined.
Still, the department is concerned with current dynamics. Ahead of the 2028 decisions, Anderson says New York City is making noise that it wants to drop the flow target at Montague, decoupling required reservoir releases from a key metric meant to protect Philadelphia from the salt line.
“We work very well with New York,” Anderson says. “This is the one issue we don’t always see eye to eye with them on.”
The white coats versus the suit coats
If this swirling uncertainty over the future safety of a drinking water source serving 17 million people isn’t anxiety-inducing enough, take a moment to consider something else: whatever the scientists come up with, it’ll be in the hands of politicians to act on the results.
That doesn’t inspire a lot of confidence in some long-time observers of the DRBC, whose policy decisions ultimately lie in the hands of four governors and the president of the United States.
Maya van Rossum, head of the environmental nonprofit Delaware Riverkeeper Network, has frequented the commission’s regular meetings for decades. Following a series of devastating floods in Bucks County in the mid-2000s, she even served on a DRBC flood mitigation task force that created new recommendations, including protections against development in floodplains. The experiences left her with the view that the DRBC is not going to be up to the task.
Information for information’s sake frankly is not helpful.”
— Maya van Rossum, Delaware Riverkeeper
“Those recommendations really went nowhere, and ended up on a bunch of bookshelves,” van Rossum says. “Information for information’s sake frankly is not helpful.”
Forget the future, van Rossum adds: the river is threatened now. The hazards of climate change are well established; sea level rise is already causing salty havoc in parts of the lower watershed; oxygen levels and habitat loss are a concern for species like the endangered Atlantic sturgeon.
And yet, van Rossum says, decisions are still made out of political expediency, including the allowance of new fossil fuel operations, approval of additional withdrawals from the watershed and the dredging of the river from Philadelphia south to the bay, which is expected to help shipping commerce but exacerbate just about every other problem, including management of the salt line.
“It’s not just thinking about every decision that’s happening today, and how does the climate play into it,” van Rossum says. “It’s also about being proactive in terms of anticipating the harms and being protective.”
Even those with differing views believe the DRBC has a tremendous challenge on its hands, requiring something different from the status quo. Neukrug serves as a volunteer chair of the recently created Climate Change Committee at the DRBC, where he says some of the region’s best scientists are starting to think deeply about how global warming will impact the watershed. At the moment, he believes there’s too much uncertainty to justify blanket banning activities such as dredging.
“That’s a serious economic issue that doesn’t need to be challenged at this point in time,” Neukrug says.
But Neukrug sees similar challenges on a longer timeline. How effectively, he wonders, can you make decisions when sea level rise could range from three feet to eight feet or more over the next century? That doesn’t mean he isn’t worried about the health of the watershed, but it does mean he doesn’t want the entire solution hinged on the release of water from New York reservoirs.
Eventually if we want to survive as a major metropolitan area — New York City, Philadelphia, Camden, Chester — you have to start thinking about broad solutions.”
— Howard Neukrug, Penn Water Center
Instead, Neukrug envisions options ranging from expanding or creating new reservoirs in control of parties downstream, improving water use efficiency, recycling wastewater, installing desalination treatment at the Baxter plant, or even finding ways to pipe in water from new sources.
“Eventually if we want to survive as a major metropolitan area — New York City, Philadelphia, Camden, Chester — you have to start thinking about broad solutions,” Neukrug says.
PWD’s Anderson and Rademaekers say they’re also planning for all potential outcomes, including desalination systems at Baxter in a worst-case scenario, although they don’t believe Philadelphians should have to foot the extremely expensive price tag for that power-intensive technology themselves.
Even Shallcross, a scientist who admits she’s sometimes frustrated by the bureaucracy and politics at play — “Policy doesn’t always follow the science,” she says — understands the nature of the difficult decisions ahead.
“Basically everything needs to be weighed, and there are tradeoffs,” Shallcross says, noting the five parties to the DRBC all have their own priorities. “So we provide the science … but you have to stand in each one of their shoes.”
