New Map Shows Contours of Delaware River’s Deepest Point

NARROWSBURG — A new map revealing the mysterious contours of the “Big Eddy Narrows” as the deepest and narrowest points on the 330-mile Delaware River is available as an 11 x 17” poster that its creator has donated to benefit the non-profit Upper Delaware Council.

Lisa Glover of Honesdale, PA converted her curiosity over Narrowsburg’s bathymetric claim to fame into creativity after discovering that the “Mighty D” runs 113 feet deep at River Mile 290 in this tiny Town of Tusten hamlet which derived its name from its other distinction of being the main stem’s narrowest part, coursing through a rock canyon that is only 200 feet wide.

For comparison, the Delaware River’s average depth is 4-5 feet (although holes of 12-18 feet aren’t uncommon).

Glover – who enjoys paddle boarding, holds a B.A. degree in Architecture and a Masters of Engineering from Lehigh University, and writes a blog called Lisa the Maker – consulted with the Upper Delaware Council (UDC) after becoming fascinated by those facts.

A historic marker at the Big Eddy Observation Deck offers two theories of how the 113-foot hole was created: 1) it is a long-drowned ‘plunge pool’ from a glacial waterfall; or 2) it is a pothole that tumbling rocks scoured out through erosion, according to HMdb.org. The Big Eddy, where the deepest point lurks downstream from the narrows, often has a visible whirlpool.

Glover read articles from the UDC’s “The Upper Delaware” newsletter which pointed her to interviews with National Park Service divers who had measured the hole, various illustrations, and spoke of a wish for an accurately detailed map of the river bottom to potentially solve the mystery. While topographic maps existed to show the elevation of landforms above “sea level”, bathymetric maps show depths of landforms below water.

Glover’s research extended to the U.S. Geological Survey (USGS) from a citation in the Summer 1993 newsletter article.

She discovered that agency had published a USGS LiDAR scan of the Delaware River in 2020 and tracked down Research Scientist John Young, who happily provided a digital map focused on the Big Eddy section.

Gathering all her resources, Glover designed a topobathymetric color map with 10-foot contour lines and to-scale cross sections of The Narrows and The Deeps, printed 50 copies, and generously offered a stack to the UDC to share with the public as a fundraiser. 

She featured an article with additional details atwww.lisathemaker.com, a site which also cites her affiliations with Highlights for Children, the Stourbridge Project, the Wayne County Arts Alliance and the Center on Rural Innovation, for which she is their Placemaking Fellow.

To request a Big Eddy Narrows poster for a $20 donation to the UDC, please contact Administrative Support Stephanie Driscoll atstephanie@upperdelawarecouncil.org, (845) 252-3022, or stop by the Council’s office at 211 Bridge St. in Narrowsburg (next to the firehouse) on weekdays for pick-up.

The supply is limited. Payment must be by check or cash. Add $3 for mail orders.