KNOWLTON — One of the eastbound lanes of Interstate 80 was closed through the Delaware Water Gap on Tuesday with a dozen-person crew doing “inspections and repairs,” said a local official.


Knowlton Mayor Adele Starrs, who has been vocal in seeking full disclosure from the state about its rockfall mitigation plans for about a mile of the highway, said she drove through the area on Tuesday, saw the closure and work crews, and stopped to question a supervisor on the scene.


“He said they were inspecting and doing minor repairs,” Starrs said. “I’m not sure it takes 12 people to make ’minor’ repairs.”


Over the past two weeks, pictures have been posted on Facebook and published in local newspapers showing possible erosion under a retaining wall which is part of the structure that holds the travel lanes of the highway as it moves through an area known as the S-curves.


In that same area NJ DOT has proposed building fences and other barriers, as well as cut back a part of Mount Tammany, to lessen the chances of rocks falling from the peak which rises about 1,200 feet above the highway.


Mount Tammany forms the New Jersey side of the Delaware Water Gap, a nationally recognized natural wonder and which lends its name to a unit of the National Park Service straddling the Delaware River which flows through the gap. The Pennsylvania side of the gap is known as Mount Minsi.


During an open house last summer a resident claims she gave a DOT representative photos of the erosion under the wall.


Starrs said Tuesday that the town now has documentation that the woman also forwarded a letter with the photos attached to DOT officials in July.


Another set of photos taken in late Februrary was posted on the Facebook page of the I80CoalitionDWG, a citizens group that formed last year to also get information from DOT and recruit citizens who are experts in the field, to look at the state’s reasoning and data on the rockfall mitigation project.


With the publication of the pictures early last week, DOT sent responses to the New Jersey Herald, as well as organizers of the Facebook page and township officials in Knowlton and Hardwick.


While the responses came from differing offices within the department, the wording was identical and that DOT NJDOT “appreciates residents bringing potential safety concerns to the attention of the Department,” and of the specific concerns, “Our inspectors conducted an initial evaluation of the structure and found the erosion poses no short-term safety concerns at this time, but the condition does need repair.”


One possible cause of the undercutting of the wall might be the road’s drainage system with outlet pipes contained in several locations in the wall. Water drains off the face of the cliffs and is directed by channels into several culverts which travel under the highway.


Over the years, lanes of the highway have been closed because of water overflowing the drains and onto the road.


Also talked about as a cause for the erosion is flooding on the Delaware River. The wall sits atop the north bank, several feet above the river.


The latest “historic crest” of the river — 13th on the list of top floods — was in late January 2018, when the river flowed at 20.08 feet at Tocks River, about four miles upstream from the gap, where flood stage is 21 feet.


In 2011, there were four flood events with higher floods with the highest on record in 1955, before the interstate was completed. The second highest reading of 33.87 feet was in 2006.


The I80CoalitionDWG is also sponsoring a petition signature drive on Change.org and by Tuesday had about 2,300 names toward its goal of 2,500 signatures.


The petition is aimed at getting DOT to stop the rockfall mitigation project until all other alternatives have been thoroughly studied.


The Knowlton and Hardwick township committees, as well as other citizens groups, are also demanding that a formal, long-form Environmental Impact Statement be completed before further work is done, other than fixing current damage to the highway system.