Preparing for the next deluge

Flash flooding near Croton Harmon Station. Credit: MTA Metro-North Railroad
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In the wake of extreme (and increasingly common) rain, Riverkeeper continues work to mitigate impacts on water quality and infrastructure

The Hudson Highlands was among the most heavily impacted regions when a massive summer storm blew through the Northeast in July 2023, dropping as much as 8 inches of rain in the space of just a couple hours in some places. This type of extreme weather exemplifies the pattern climate scientists have warned us to prepare for, and its impacts were severe.

The storm took the life of a dedicated Riverkeeper volunteer, Pamela Nugent, who joined numerous Sweep cleanup events with her family. The Riverkeeper team is mourning her loss, and has been in touch with her family to express our condolences. A fundraiser has been established to support the family.

The deluge has made news for the shocking and varied impacts it had. In several instances, these impacts exemplify the vulnerabilities facing our waterways and water infrastructure from extreme storms.

Inadequate stormwater infrastructure puts people at risk

Torrential rain washed out roads and railroad lines, knocking out Metro-North and Amtrak service and virtually isolating the U.S. Military Academy at West Point. “Having 8 inches of rain in such a short period of time just overwhelmed the infrastructure… Once it started, this flash flooding, it just got worse and worse,” Orange County Executive Steve Neuhaus told WAMC. Riverkeeper has acted as an advisor on water resources as New York State prepares a landmark Climate Impacts Assessment, including raising the need to update stormwater infrastructure design guidelines to account for extreme storms.

This video shows a stormwater pipe that was overwhelmed to the point that a state highway washed out around it:

Route 218 (Storm King Highway/9W) in Orange County, New York/#HudsonValley has sustained catastrophic damage.

A summer’s worth of rain fell in a single day.pic.twitter.com/uVq9u9QSbw

— Ben Noll (@BenNollWeather) July 10, 2023

Flooding adds to the dangers posed by obsolete dams

Many hundreds of obsolete dams are found throughout the tributaries of the Hudson River. A large majority of these dams were constructed for industries that no longer exist, and they were not built – nor have they been maintained – to withstand the increasing frequency of extreme storms. Riverkeeper has been studying the Walsh Road dam on the Quassaick Creek in Newburgh because removing it would restore significant habitat for fishes that are currently blocked from historic spawning and nursery areas that are critically limited. There are also safety considerations. Removal of the dam will help mitigate a persistent flooding problem for upstream communities while also eliminating an attractive nuisance that places residents of Newburgh and surrounding communities at serious risk should they fall into the fast-moving water anywhere near the dam.

It’s not clear how many dams were stressed or compromised by the storm, but at least two in the Adirondacks and at least one on the Massachusetts portion of the Hoosic River failed, according to news reports. Removing dams under highly controlled conditions is the safest way to restore habitat and boost community resilience in the face of extreme weather risks. Visit Riverkeeper.org/dams to learn more.

Outdated and at-risk sewage infrastructure causes pollution

The storm also contributed to the failure of a sewage pump station in Sleepy Hollow, prompting a warning to avoid contacting the Hudson River, and “completely compromised” a sewage treatment plant in the Town of Highlands and disrupted the treatment plant at West Point, according to the Department of Environmental Conservation (DEC). Both were substantially repaired by July 13. Many others are just as vulnerable: Of 140 municipal wastewater treatment plants in the Hudson River Estuary watershed, nearly 40% are within the 500-year floodplain, according to a DEC analysis.

An estimated 14 million gallons of sewage overflowed in Yonkers July 9, according to a Sewage Pollution Know Right alert. Importantly, this kind of overflow from a combined sewer system – significant, but fairly routine – does not prompt a public health alert, and yet it puts swimmers, paddlers and children visiting the shoreline at risk in New York’s third-most populous city. Even though the rain was not extreme in New York City, combined sewers overflowed with raw sewage from hundreds of locations. This too, unfortunately, is a chronic problem. Riverkeeper is working to ensure that updated New York State water quality standards, and Westchester County’s emerging plans to consolidate sewer infrastructure, move forward in ways that help reduce sewage overflows.

This video shows a sewage overflow July 9 from Westchester County’s sewer system at Sleepy Hollow, near where the Pocantico River meets the Hudson:

Sewer discharge at Horan’s Landing Beach in Sleepy Hollow at emergency sewer outfall

Floodwaters stress drinking water sources

The City of Peekskill will rely on stored water or its backup supply until its primary water source, Peekskill Hollow Brook, returns to normal levels of clarity. The flood waters – exemplifying emerging risks to drinking water here and elsewhere – were not only filled with eroded sediment, but contaminated from sources such as home fuel oil tanks that were compromised, commercial areas that were inundated, and other sources. Most if not all of these problems will recede with flood waters, but in some cases, mobilized contaminants or eroded stream banks can create persistent problems that will require restoration.

Riverkeeper is working to help communities understand risks to drinking water from climate extremes – both drought and deluge – in order to improve resilience and adaptation planning. Riverkeeper is also working with Peekskill to study and define protection methods for its water source.

Flash flooding near Croton Harmon Station. Credit: MTA Metro-North Railroad

A multi-hazard approach to planning is needed

Making our communities, water infrastructure and water sources resilient to climate extremes is a complex undertaking, given the distinct but overlapping risks posed by flooding, sea-level rise and storm surge. Most urgently, Riverkeeper is advocating for a well-rounded, locally-defined flood protection plan for New York City and neighboring communities that would address these multiple hazards, in contrast to the U.S. Army Corps of Engineers’ current $52 billion proposal. The Corps’ plan focuses too narrowly on storm surge risks, and relies on ecologically damaging storm-surge barriers. It’s urgent that we demand smarter solutions.

Riverkeeper President Tracy Brown discussed this on WNYC’s The Brian Lehrer Show. You can listen to the interview here and learn more at Riverkeeper.org/barriers.

All year long, you can support Riverkeeper’s efforts to restore the Hudson River and its connected waters by becoming a member and adding your voice in support. To stay up-to-date, please join our mailing list.