The risks of the low-head dam in Jonestown are nothing new, but that’s not stopping local officials from taking additional steps to make sure the public is aware of the danger.

The dam itself dates back to the early 1900s, when it was constructed by a local water company to supply an adjacent water treatment plant. The dam has been under the purview of the City of Lebanon Authority since 1952, and today its intake pipes supply an authority water treatment plant in Swatara Township, some three miles south.

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Low-head dams accelerate water as it heads over the dam, and then creates a suction dynamic below the dam that can prevent individuals or vessels from reaching the surface or escaping the boil.

Low-head dams are known as “drowning machines” due to the dangers they pose to users who might not recognize the structures or know about the hard-to-escape currents they produce. (Weather.gov)

“The danger is that the water gets a lot of air in it which makes people and objects less buoyant and they sink,” said Lebanon Authority executive director Jon Beers. “The second problem is the water swirls backwards towards the dam at the surface and keeps sucking things back to the dam, and then you sink again, in an infinite loop.”

The low-head dam in Jonestown.

In an April 2022 incident, a mother and son drowned at the dam in an accident while fishing on top of it. Two others with them were able to be rescued from the water, suffering only minor injuries.

The deaths deaths were not the first at the dam – an incomplete search of local archives shows multiple fatal incidents, including one in 2020 as well as the 1992 deaths of two canoeists who got trapped in the undertow of the dam during a December outing. Their deaths were attributed by state police to cold water drowning.

Although nothing with the dam itself has changed to make it more dangerous, a few factors have led to increased public exposure. In 2019, an extension of the Lebanon Valley Rail Trail opened that runs by the dam, exposing passersby to the facility that was previously a quarter mile from any public roads. While access to the dam from the rail trail is not possible due to a fence that encompasses the site, Beers said that previously, except for the occasional kayakers and canoeists, very few people even knew the dam was there.

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“People go there to fish, might be curious and want to swim there,” said Northern Lebanon Fire and Emergency Services commissioner Rob Taylor. “They get into a situation and don’t know what to do.”

Fence and signage around the Swatara Creek Intake facility and adjacent low-head dam at Jonestown.

Jonestown Borough Mayor Joe Quairoli also said that the presence of the rail trail has increased public curiosity regarding the dam. Quairoli said that the priority for him and other authorities is educating the community on the risk of the dam.

Both the borough and the authority have recently added signage in Spanish to make sure that all users of the watershed are informed of the danger.

In particular, the borough has added signage to its boat launch, including bilingual “no trespassing” signs to deter visitors. The only land-based route to the dam would be through private property.

Signage at the Jonestown boat launch.
Signage at the Jonestown boat launch.

Both Quairoli and Beers noted the increase in usage of the Swatara Creek, especially in the wake of the COVID-19 pandemic, another factor that has magnified the opportunities for the dam to entangle a member of the public.

Read More: Outdoors lovers enjoying activities on Swatara Creek in record numbers

“During the COVID pandemic, people were not traveling and they looked for local things to do and spend recreational money on,” said Beers. “Fishing, rafting, and boating might have been a few things people started to do to pass the time.”

Boating on the “Swattie” is easy and beautiful thanks to its calm waters and healthy forests. (Will Trostel)

There is a portage on the left hand side of the creek that allows users of the creek to bypass the dam safely. With the Jonestown boat launch sometimes used for egress by people canoeing or floating down the river, it’s critical for those users to take the portage when they come to the dam.

Buoys are in place prior to the dam to advise of the dangers ahead, as well as downstream of the dam to warn those who might be working their way upstream from the boat launch.

“Probably the biggest thing, if people are going to be in that area, they need to educate themselves on the dangers of a low-head dam, what that is, and abide by the signs,” said Quairoli.

While some ideas have been floated for how the site could be physically transformed to make it safer, such as adding more fencing or concrete steps, ultimately two powerful forces stand ready to complicate those efforts – ever-flowing water and nature itself.

“The problem is that any objects we would install to keep people away from the dam will get wiped out in a flood, such as fencing, barbed wire, cables,” said Beers.

Quairoli echoed that sentiment.

“You could put rocks there, you could put concrete steps there, there could be a long concrete slope as well, but you’re battling Mother Nature and we know you’re not going to win that battle,” said Quairoli.

“Mother Nature is unforgiving.”

Buoys upstream of the low-head dam. (Provided photo)
If you are seeing this view of the dam, you’re probably somewhere you shouldn’t be. (Provided photo)

Taylor said that emergencies at the low-head dam are very resource-intensive for the department. “For us, it’s a technical rescue, it takes manpower and a lot of training and equipment,” said Taylor.

Taylor said he hopes the public simply abides by the posted signs.

Beers echoed that message – If members of the public respect the posted guidance, they’ll be fine.

“Simply stated, if anyone is walking, fishing, or playing on or near the dam, then they have completely ignored all of the warning signs,” said Beers. “You cannot miss the signs.

“And if they walked, they will have crossed private property to get there.”

With multiple parties working to make the dangers of the dam clear – the water authority, the commonwealth, the rail trail, and the borough – situational awareness is arguably the most important thing for users of the creek to bring with them.

“The biggest thing is being educated about the danger,” said Quaroli.


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