July 18, 2022
A section of the Stony Clove Creek that is a substantial source of fine sediment has become the latest in a series of stream restoration projects to be constructed by the Ashokan Watershed Stream Management Program.
The project is located about a mile north of Lanesville in Greene County along State Route 214. The Stony Clove Creek is the largest tributary to the upper Esopus Creek, which supplies water to the Ashokan Reservoir, a component of New York City’s drinking water supply.
Construction extends along 1,600 feet of stream length and will cost just over $2 million, making this one of the largest stream restoration projects completed in the Ashokan watershed.
Construction of the Stony Clove Creek stream restoration project began in June and will end by September 2022 if high flows don’t cause delays.
The project designers used Ground Penetrating Radar to determine the depth of stream-deposited soils throughout the project site. At some locations “lacustrine” (or glacial lake) clay was found only six inches below the ground surface.
Designers chose a new course for the channel where clay was found over four feet below the surface, aligning with the path of a historically stable channel. The Ulster County Soil and Water Conservation District hired SLR Engineering to develop the project design.
The design for this site was challenging because of the fast water velocities combined with abundant sediment deposition. But a wide valley at the site gave project designers more room to work when choosing a new channel alignment.
The stream channel will be reshaped and relocated by project end. Grading will soften the steepest banks to arrest active slope failures. Instream rock riffles and large wood revetments will be installed to stabilize the channel bed and banks.
These features naturally occur in Catskill streams and provide structure for fish habitat. The final important step will be to plant and restore native trees and shrubs to “bioengineer” long-term bank protection.
After the stream flow is diverted into a bypass pipe around the construction site, Cory Beesmer with Kingston Equipment Rental scoured the remaining pools of water with a bucket in hand looking for slimy sculpin, longnose dace, and trout left behind. The stranded fish were rescued and transported downstream.
The downstream end of the restored stream channel will hook into a section of the Stony Clove Creek featuring a highly stable transverse sediment bar and overhanging vegetation that shades and cools the stream during summer heat.
The Ashokan Watershed Stream Management Program (AWSMP) is a collaboration between the Ulster County Soil and Water Conservation District, Cornell Cooperative Extension of Ulster County, and the NYC Department of Environmental Protection.
For more information about this stream restoration project, contact the AWSMP at (845) 688-3047.