Mud in the Water: The Fight Over Turbidity in Esopus Creek | Environment | Hudson Valley | Chronogram Magazine

Last Christmas, an unseasonably temperate rainstorm followed a major snowfall in the Catskills, turning the Esopus Creek in Ulster County an opaque reddish-brown. The creek, which runs through Marbletown and Hurley before skirting Kingston and meeting the Hudson River in Saugerties, was likened to a “muddy ditch” and “chocolate milk.”

But residents, some local officials, and the environmental group Riverkeeper blamed the state of the creek on sediment-filled discharges released by the New York City Department of Environmental Protection (DEP) during storms.

Since 2010, the DEP has discharged hundreds of billions of gallons of turbid water into the creek to take pressure off the Ashokan Reservoir, the largest reservoir in NYC’s water-supply system, when it becomes muddy or overfilled. Ulster County threatened to sue the DEP in 2011 under the Clean Water Act, eventually forcing the DEP to seek a permit from the state to continue the discharges.

The DEP violated multiple aspects of the permit, and now is under a Consent Order with the New York State Department of Environmental Conservation to review the discharges and any impacts they have on the Esopus Creek. In the meantime the discharges have continued on a provisional basis under an Interim Release Protocol, which lays out the circumstances in which a discharge can be made.

The DEP released a draft Environmental Impact Statement last year asserting that the discharges have no impact on the creek. However, Riverkeeper and local officials are pushing back on this claim, saying the discharges make the creek shallower with deposited sediment, harm wildlife, and destroy the aesthetics of the creek. With climate change expected to bring more precipitation to the Catskills, the discharges will only be more frequent in the future.

The Discharges

The Esopus used to flow unencumbered down the eastern Catskills, but it was dammed in the early 20th century to create the Ashokan Reservoir, which is still fed by the creek. Robert Titus, the author of The Catskills: A Geological Guide, says glaciers flowing down the Hudson Valley at the end of the last ice age created a glacial lake in what is now the upper Esopus watershed. The lake “accumulated enormous amounts of red silt,” which remain to this day and are picked up by the upper Esopus during rainstorms.

This turbid water flows into the western half of the Ashokan, where the red silt and clay settle before the water passes to the eastern half of the reservoir. The water, now clear, continues through the Catskill Aqueduct to the Kensico Reservoir in Westchester County, then on to millions of faucets in New York City.

The discharges come from the western, turbid half of the reservoir. Since 2010, the DEP has discharged massive amounts of turbid water into the lower Esopus on nearly 50 separate occasions, according to the draft Environmental Impact Statement, some of which lasted weeks. The stated reasons are to mitigate flooding and to pump turbidity out of the reservoir so the sediments do not travel farther down NYC’s water-supply system. After the storm in late December, the DEP released more than 450 million gallons of turbid water a day into the lower Esopus for nearly a week and continued discharging lesser amounts until late February.

click to enlarge Mud in the Water: The Fight Over Turbidity  in Esopus Creek
DEP Environmental Impact Statement

In interviews with The River and during a March 2 public hearing on the DEP’s report, local residents complained the discharges were the latest in a string of DEP abuses. Paul Malmrose, a technical consultant for the seven municipalities that draw drinking water from the Hudson River, says New York City was trying to “pawn off” its issues with turbidity to Hudson Valley communities.

“We’ve given New York City more than enough—we’ve given them our land, they’ve taken over our towns, they’ve flooded our towns, now they’re destroying our river,” Malmrose says, in reference to the tens of thousands of acres in the Catskills purchased by the DEP to protect its water-supply system, the latest in a line of grievances that began with the construction of the dam, when the city removed residents of 11 mountaintop communities and burned their towns. “New York City should solve their own problem, not give it to us.”

The DEP makes three different types of discharges through the release channel. The first are “community” discharges: small, background discharges of clear water meant to consistently hydrate the lower Esopus’ banks.

The two other types of discharges are more controversial. An “operational release” discharges turbid water into the Esopus before it can enter the eastern half of the Ashokan and affect the Kenisco Reservoir farther south, according to the Interim Release Protocol. The DEP made operational releases multiple times in 2008, 2009, and 2010.

The stated reason for the third type of discharge is to prevent flooding. Before this method was introduced, floodwaters entering the western half of the reservoir passed into the eastern half in the normal fashion, then over the reservoir’s spillway, entering the lower Esopus as clear water just downstream of the release channel.

But in April 2005, a rainstorm and melting snow pushed a deluge of water over the spillway, causing massive flooding along the lower Esopus. Waters from the creek and other rivers in Ulster County seriously damaged or destroyed 400 homes and led to 40 water rescues, according to The Daily Freeman.

Residents and elected officials demanded the DEP begin drawing down reservoir levels in anticipation of storms, eventually leading to the organization to incorporate “spill mitigation releases,” the third type of discharge, into the Interim Release Protocol. The DEP now limits reservoir levels to 90 percent of capacity between mid-October and mid-March in anticipation of spring flooding.

Drone footage of turbidity in Esopus Creek. Credit: Michael Nelson

“Spill mitigation releases” essentially flatten the curve of flooding events on the lower Esopus, according to DEP spokesman Adam Bosch. Instead of a rainstorm pushing the Ashokan over the spillway and into the lower Esopus in an uncontrolled deluge, the release channel can slowly let out the excess water over many days.

The release channel has been used for flood mitigation more than three dozen times since the Interim Release Protocol was instituted, according to the DEP, often for weeks on end. The agency predicts water will be discharged through the channel for flood mitigation on 22 percent of all days in the future.

The View from the Lighthouse

Patrick Landewe has been the keeper of the Saugerties Lighthouse for 15 years. The lighthouse sits in the Hudson River, a few hundred feet from the mouth of the Esopus; living there through years of discharges has given Landewe an important vantage point on the issue.

Water exiting the Esopus generally looks the same as the rest of the water in the Hudson, he says. But during discharges, “you can see the contrast.”

Landewe says he hasn’t observed clay particles from the turbid releases impacting the depth of the creek or its delta. The real issue, he believes, is the lengthy duration of the discharges.

“In the normal cycle, you have a rain event, you have the turbidity for a short amount of time, and then things return to normal,” he says. “These turbid releases that last for extended periods of time—those are the impacts that need to be considered.”

In the winter of 2011-12—which followed flooding from Hurricanes Irene and Lee—and again in the winter of 2018-19, the DEP discharged turbid water into the lower Esopus for months on end. The DEP will periodically flush the release channel to clear the creek of turbidity during these long-term discharges, but Landewe says those flushes have little effect.

click to enlarge Mud in the Water: The Fight Over Turbidity  in Esopus Creek
Turbidity in the Esopus Creek near the Saugerties Lighthouse after a 2011 discharge.

SUNY New Paltz biology professor Dr. David Richardson, an expert in Hudson Valley aquatic biota, says turbidity is a natural occurrence, but humans can increase it by modifying the surrounding landscape, leading to “a whole bunch of effects on aquatic life.” Though he can’t speak to the particular details of the Ashokan discharges, he can explain the impacts of increased turbidity in general.

“The definition of turbidity is just decreased transparency, which might lower the amount of light that’s available for aquatic life at the bottom—things like plants and phytoplankton that serve as the base of the food web,” he says. Increased turbidity can also raise the temperature in water, since darker materials absorb more heat energy from the sun, which can change a waterbody’s ecosystem.

Frank Ostrander, the secretary for the Marbletown Sportsmen Club and an avid fisher of the Esopus since the 1990s, says the number and quality of fish on the creek has declined since the discharges began.

“The most stark thing is, I used to see these big, chubby bass swimming around, and I don’t just see them anymore—they’re skinny,” he says. There aren’t many carp in the creek anymore, which Ostander bow-hunts. “I used to go on that water and shoot 30 fish. Now, I get two, and I’m lucky.”

Erosion is another issue. “It’s had a negative effect on our shoreline,” says Leanne Thompson, president of the board of directors for the conservancy organization that maintains the Esopus Bend Nature Preserve, which features a series of trails winding through forest and wetland on the south bank of the creek. “We’re dealing with erosion; we’re dealing with sand bars that are no longer there.” Thompson also says that the creek has been made shallower by clay and silt from the discharges that gets deposited along the creek bed.

The DEP denies such assertions in its draft Environmental Impact Statement, claiming that the discharges do not result in sediment deposition and that the increased turbidity in the Esopus is from other sources in the watershed. Bosch says these include the Plattekill and Sawkill Rivers—tributaries of the Esopus—and the various runnels that feed the creek on its path to the Hudson River.

Other Options

The late-December storm was particular in two ways, Bosch says. The first was the sheer amount of water it produced. The region had received up to 2 feet of snow two weeks earlier, and the rain combined with melting snow to produce the 10th-largest runoff event in the history of the reservoir.

The Catskill Aqueduct, which pipes water from the Ashokan to the Kensico Reservoir, was also closed for repairs during the storm, Bosch says. No water could exit the Ashokan via the aqueduct, leaving the release channel the only option.

Hypothetically, instead of discharging through the release tunnel, the DEP could have let the reservoir fill until the water flowed over the spillway and into the Esopus, as it did in prior decades. The spillway is in the eastern part of the reservoir, so the water would be clear. And Bosch says the storm did not produce enough water for the Esopus to flood.

“The Interim Release Protocol requires us to aim to keep the reservoir below spill,” he says. “We can’t just let it fill up and spill…that’s not what the protocol calls on us to do anymore. It calls us to make these releases to minimize the possibility the water passes through the spillway.”

Paul Gallay, the president of the Hudson Valley environmental group Riverkeeper, calls the DEP’s claim that the discharges are not to blame for turbidity in the Esopus after storms “an insult” and “a failure to come to grips with the damage that they’re doing.”

“The DEP flinched when it came time to straightforwardly analyze the solutions that would solve the problem, and now they’re trying to paper over the problem rather than making the investment necessary to solve it.”

The draft Environmental Impact Statement presents a list of alternatives release methods, but rejects them for a variety of reasons, stating the current discharges are the only feasible method. Public comments on the draft statement are being accepted until June 16 and can submitted to [email protected]. After then, it’s up to the state DEC to make a decision. Gallay, who worked as an attorney for the DEC before joining Riverkeeper, says the state agency cannot “accept the DEP’s effort to shirk responsibility.”

In the coming years, the primary impact of climate change on the Northeast is expected to be increased precipitation, primarily from larger storms, which would lead to more floodwater cascading over the red clay of the Catskills and into the Ashokan Reservoir. Whether the turbidity seen in the lower Esopus is a result of the discharges or not, one thing is for certain: there will be more chances to find out.

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