LancWatershedM18

The Scribbler has long been interested in the stream and spring water piped beneath Lancaster city to the Conestoga River. So he was eager to hear Steve Sylvester’s presentation on the subject to the Millersville Area Historical Society.

A retired research specialist for the Franklin & Marshall College Earth and Environment Department, Sylvester discussed the history of “the lost river of Lancaster” and its several sources.

Lancaster residents called this “river” Roaring Brook in the early 18th century. It was later known as Bethel’s Run, Hoffman’s Run and Gas House Run. Roaring Brook’s main stem ran north to south — from several springs in a wetland along Walnut Street between Mulberry and Charlotte to the Conestoga River at Engleside.

The stream’s largest tributary began northwest of the present intersection of Manor and Dorwart streets on Cabbage Hill and joined the main stem just north of today’s Andrew Street. Other tributaries flowed from the east near Lime Street.

Roaring Brook and its tributaries ran through at least three wetlands: Dark Hazel Swamp, Long Swamp and a wetland in the headwaters of the main stem of Roaring Brook.

Roaring Brook’s watershed extended over 1.6 square miles, including what is now the city’s center and most of its southern end.

When Lancaster was a small town in the early 1700s, its residents could live with water all around them. But as the city developed, water increasingly impeded development. So it was piped underground.

“As people move into any city in the northeast, they come into a conflict with water,” Sylvester said.

(While burying all of that natural water, the city had to build a reservoir in 1837 to pipe in water from the Conestoga, as noted in a previous Scribbler column. Early planning foresight, one might say, was minimal.)

To “de-water”' the city, workers dug a trench down the length of Water Street and used a huge underground pipe to carry not only Roaring Brook but all water from its drainage basin down to the Conestoga.

About 1870, the Philadelphia and Reading Railroad completed the job when it built a spur along Water Street. The railroad bed completely covered an arched sewer carrying Roaring Brook. At the outlet into the Conestoga at Engleside, the sewer is 10 feet in diameter, buried under 15 feet of fill.

That sewer and other sewer lines feeding into it carry the former flow of Roaring Brook and sewage to the city sewage treatment plant. As development increased, stormwater flowed faster into sewers. During major storms today, stormwater overwhelms the sewage treatment plant, forcing a mixture of stormwater, Roaring Brook water and sewage to flow directly into the Conestoga.

Lancaster designed its 2011 Green Infrastructure Plan to slow groundwater runoff into the sewer system.

Sylvester also described how geologists, hydrologists and others have studied the Big Springs Run watershed in West Lampeter Township. Big Springs’ watershed is similar in size to Roaring Brook’s watershed. It includes farmland, pastures and parts of Willow Street.

Observed Sylvester, “Big Springs can give us an idea of how often Roaring Brook flooded when Lancaster was a much smaller city surrounded by pastures and farmland.”

Jack Brubaker, retired from the LNP staff, writes “The Scribbler” column every Wednesday. He welcomes comments and contributions at scribblerlnp@gmail.com.