“Catastrophe” is not a word that municipal officials tend to use very often, but Town of Rosendale Highway Superintendent Bob Gallagher resorted to it last week, following his periodic update on capital projects to the Town Board. The subject of his concern was the current state of the concrete apron holding up the northern bank of the Rondout Creek just downstream of the Keator Avenue bridge. “The panels have shifted out, and there’s nothing holding them up,” Gallagher said. “The water comes underneath the apron into the creekbed, and excavates up to seven feet deep underneath.”
The water runoff in question, according to Gallagher, comes from the caves and shafts that riddle Joppenbergh Mountain, dating back to the heyday of Rosendale cement. Frozen soil in the winter months means that the rainwater from an unusually wet autumn and more recent snowmelt can’t drain back into the aquifer and is spilling down the mountainside, across and under Main Street and pushing against the bank, inexorably peeling the concrete retaining wall away from it.
“There is a shift in the ground. The water coming off Joppenbergh has no place to go,” Gallagher explained. “It just digs. All those mines and shafts – I don’t think any of us can comprehend in this day and age how much all those mines hold. In the event that catastrophe happens and those walls give way, what will happen? We don’t know. If there’s too much pressure, the water on the mountain could take everything out.”
Gallagher reported that the New York State Department of Environmental Conservation (DEC) “sent divers into the creek” to investigate the extent of the erosion after the problem was first detected in December. A state contractor is now partway through constructing a temporary roadway through the creekbed to provide construction equipment access to the threatened retaining wall. “We don’t know how long it’s going to take,” he said. A construction zone has been fenced off at the top of the embankment on the south side of Main Street, behind the Roos Arts and Canal Press buildings, and a wooden staircase built down the side of the affected concrete wall.
This issue is the latest of many woes that have beset the Rosendale Floodwall project, originally constructed back in 1970 under a contract by the US Army Corps of Engineers to mitigate seasonal flooding in downtown Rosendale. After completion, the project was turned over to the DEC and the Town of Rosendale for maintenance and operation. Another section of the flood control project, slightly downstream of the area of current concern, sustained considerable damage from scouring and shoaling of flood-dislodged debris during Hurricane Irene.
According to a DEC spokesperson, “An underwater investigation was conducted in December 2018 to assess the condition of the wall and it was determined that a scour hole in the creekbed at the front of the wall and under the monoliths (wall sections) had undermined the wall footings and repairs were needed. Repair work will include the placement of grout bags beneath the front edge of the wall footing and tremie grout will be pumped to reestablish stable toe for the wall footing. Rip-rap will be placed in the front of the monoliths and tieback ground anchors will be installed.
“A contractor working for OGS [the New York State Office of General Services] is currently constructing a road that will be used to access the wall for the repair work. Once the repairs are complete, a portion of the road above the water will be removed, but part of the road in the water will be pushed off to the original design elevation and left in place. After the project is complete, the creekbed will be restored.
“A workplan has been established to execute the repairs. An exact timeline has not been developed because weather and field conditions can always impact the schedule.”