Seneca Aqueduct



Mile 23 - Seneca Creek winds through Montgomery County and empties into the Potomac here.  It originally had three arches, the repaired remains of the third can be seen on the left.  Seneca Creek often floods during the early spring.  The parking lot, boat launch and park here are very busy.  It is accessible off River Road via Riley's Lock Road, named after the last lock keeper on the canal.

Dam 2 forms a still water here which is why you often see Jet Ski's out on the waters on a sunny weekend afternoon.

A nearby plaque reads:

Canal engineers built aqueducts to bridge canal boats over rivers and large streams such as Seneca Creek. Eleven aqueducts were needed between here and the canal's western terminus at Cumberland, Maryland; all required skilled quarrymen and stonemasons, and large outlays of scarce capital.

Seneca Aqueduct opened to traffic in 1833, and along with through-boats from the west, carried a substantial local traffic in lime, grain, fertilizer and sandstone to and from farms and industries around Seneca. Made of red sandstone from nearby bluffs, it has long been one of the most admired canal structures.

Freshlets and flooding on Seneca Creek have always caused problems, and finally in September, 1971, almost 50 years after the canal closed, a violent local flood swept away one of the arches.

The last locktender at Seneca was Johnny Riley, whose former lock and lockhouse are at the east end of the aqueduct. "I don't care what hour of the night it was," recalled a former boatman, "any hour of the night you boat to his lock and holler...there was his lantern waving you ahead."

A description of the Seneca area from Towns Along the Towpath.

Mile 23 - This is a very well preserved lock house, the last one to operate on the canal. A lot of the lock houses are either locked up, in ruins or long gone, so this one is well worth seeing.  More details in the page "Riley Lockhouse Tour", coming up next!

This aqueduct is unusual in that it is combined with Lock 24.

As the sign says, Calleva is an Outdoor Educational Program, mostly a summer camp for adventure near and around the area. Visit their web site for more about the programs they offer.  Around Halloween they run Markoff's Haunted Forest, a top notch haunted forest experience nearby in Poolesville.  Recommended.