CHICHESTER, N.Y. — Two large stream restoration projects are set to begin in Silver Hollow near Chichester, NY carried out by the Ashokan Watershed Stream Management Program (AWSMP). The projects aim to restore segments of Warner Creek to a stable and more functional condition about 1.3 miles upstream of where Silver Hollow Road intersects with State Route 214. Work will begin in July and continue through October 2021. The projects combined will restore 1,100-feet of stream channel and four acres of stream corridor.
The projects will cost about $746,684 to construct. Funding for the stream restoration projects is provided by the NYC Department of Environmental Protection as part of its Stream Management Program.
The stream program has monitored the project sites for years. The sites became particularly unstable following floods in 2010 and 2011. Large, downed trees piled in the creek causing the channel to shift into a previously forested floodplain. Once stream flows began cutting into the forest underlain by finely textured soils, the sites became a water quality concern.
The forest terrace where flows are now cutting a new channel is feet higher than the stream and thick with fine soils such as silt and clay. Streams can carry fine soils long distances to downstream water bodies. Warner Creek flows through Silver Hollow into the Stony Clove Creek at Chichester, which empties into the Esopus Creek at Phoenicia. Both streams are historic trout fisheries and recreational destinations, and feed New York City’s Ashokan Reservoir, a large drinking water supply in northwest Ulster County.
When the stream program began monitoring the sites a person could easily hop across the creek, but 10 years later the channel has widened to more than three times its original width. The creek inhabited by fish needing cool water to survive is now running shallow over heated rocks at the sites.
Both restoration projects are being managed by the Ulster County Soil and Water Conservation District (SWCD), a collaborator in the AWSMP. The SWCD hired Milone & MacBroom, Inc. (now SLR Engineering) to develop restoration designs for the stream channel and banks. The construction contract was awarded to Baker Brothers Excavating, Kingston Equipment Rental in Hurley, NY to install both projects.
Restoration designs call for the current flat and overwide channel to be narrowed. Channel-obstructing wood will be removed and re-used in engineered bank stabilization treatments. The restored channel will once again occupy the former floodplain and will remain located away from Silver Hollow Road.
According to Ulster County SWCD Executive Director and project manager, Adam Doan, the projects will re-create pool and riffle features. These natural stream features stabilize the channel bed and provide fish and aquatic insects with habitat they need.
Project benefits should extend well beyond the sites. “Stream restoration projects can benefit entire reaches of stream,” said Doan. “In addition to improving water quality as far away as the Ashokan Reservoir, the projects should reduce an upstream source of cobble and wood that might otherwise cause erosion when it accumulates at downstream properties.”
The SWCD will monitor the sites for years after construction to evaluate how the projects perform and to make repairs if necessary. The U.S. Geological Survey will monitor suspended sediment and water quality above and below the project sites. The NYC Department of Environmental Protection is monitoring channel condition and water quality in both Warner Creek and Stony Clove Creek.
In addition, a unique study to evaluate how the restoration projects affect aquatic habitat is underway with grant funding provided by the AWSMP. Research biologists at the U.S. Geological Survey will survey the fish community at both project sites before and after construction, and the SWCD is assessing habitat changes.
The studies were recommended by the AWSMP Stakeholder Council in a 2018 report identifying research priorities for the Ashokan Reservoir watershed. Study results will be analyzed as part of a long-term effort to evaluate the effects of stream restoration projects on fish habitat, water quality, and stream condition in the watershed.
“In all, we hope to learn more about how our practices affect stream temperature and physical habitat structure,” said Doan. “We always try to take a comprehensive approach to stream management to create the most benefit for watershed residents.”
The Ashokan Watershed Stream Management Program 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. The stream program office in Shokan, NY can be reached at (845) 688-3047 or info@ashokanstreams.org. For more information on outreach programs, funding, and stream projects go to www.ashokanstreams.org.
–Leslie Zucker, Cornell Cooperative Extension