Delaware Aqueduct repair remains in limbo

The possibility this year of seeing the three-times postponed Delaware Aqueduct repair go forward remains in limbo.

The repair was “paused” with the announcement by New York City Mayor Eric Adams in November 2024 as part of a broader roll out of water-conservation measures as the city experienced its longest rainless streak in recorded history.

The pause was built on the assumption that repairs would go forward in October 2025 much as they had begun last October.

According to Jennifer Garigliano, the executive director of strategic operations and research at New York City’s Department of Environmental Protection, there are “critical” conversations taking place in the immediate future that will help determine whether the repair will go ahead this coming October.

Keeping the flow going

She offered her assessment today at the meeting of the Regulated Flow Advisory Committee, one of several advisory committees of the Delaware River Basin Commission, charged with advising the commission about the views of fishery, boating and industrial groups and other resource management agencies in addition to those of the decree parties. (More about the RFAC from the Resolution No. 2005-18 that created it.)

And from that resolution: “RFAC shall include one representative each from the Commonwealth of Pennsylvania, the City of Philadelphia, the State of New York, the City of New York, the Delaware River Master, and the U.S. Army Corps of Engineers, and two representatives each from the states of Delaware and New Jersey.”

Looking at the Delaware River, it would be hard to imagine the thousands of hours that go into keeping it flowing smoothly and supplying more than 14 million people with their drinking water.

The RFAC is one of the DRBC committees where it’s easy to get lost in the very-important weeds — the human infrastructure that supports the water systems that supply our drinking water. Warning: Lots of alphabet soup coming up!

How it all works

The RFAC is one of the key players in keeping that flow, and obeying the 1954 U.S. Supreme Court decree to keep the flow at 1,750 cubic feet per second (cfs) at Montague, N.J.

Another part of managing that flow is the Flexible Flow Management Program, agreed to by the decree parties (Delaware, New Jersey, New York, New York City and Pennsylvania) in 2008, which attempts to balance the needs of those parties. And this FFMP is managed by the RFAC.

The most recent FFMP was for 10 years and each year there’s a review of how the FFMP did its job. Today there was a review of last year’s data, presented by Sara Sayed, a water resource scientist at the DRBC.

Often, there are complaints from some of the interested parties about the allocation of water. Of course, that depends on how much there is to allocate — and in 2023-24, the precipitation was largely generous.

That scenario offers an obvious comparison to the state of play this year, with precipitation scarce and undercurrents of drought and what that might imply, for example, to the Delaware Aqueduct repair.

Along with managing the flow, the recent FFMP asked for studies of various aspects of river management, as discussed by Amy McHugh, the deputy Delaware River Master.

The studies are listed here and performed in order. Three of them have been approved with the storage study being the most recent. That study will dovetail with the DRBC’s ongoing study of water storage in the basin.

Tracking the river’s salt intake

But, in addition to the pause in the Delaware Aqueduct repair, the joint star of today’s RFAC meeting was the continuing study of the impacts of salt in the basin as a whole and specifically in the Special Protection Waters north of Trenton.

Delaware Currents has done a host of stories about the issue of salt, most recently for Winter Salt Week, and a companion piece, “Road salt pollution isn’t just a winter problem anymore.”

But there are two types of salt that worry scientists and regulators: road salt, called terrestrial salt, and ocean salt. Above Trenton, the concern is focused on the former, especially as salt is degrading those Special Protection Waters. Below Trenton, sea-level rise is increasing attention to the salt front, the line where salty ocean water reaches up into the estuary. Though road salt is a problem here, too.

The discussion today indicated that scientists are increasingly able to discern which salt comes from and where.

The DRBC is hosting an ad-hoc workgroup formed from the Water Quality Advisory Committee called “Salinity Impacts Freshwater Toxicity,” another acronym, SIFT.

Here’s one of the slides shown by Elaine Panuccio, a senior water resource scientist at the DRBC. It shows many of the groups working on the issue with the DRBC, and also indicates there isn’t an easy solution to the problem.