SHOKAN, N.Y. — A new ‘Stream Guide’ fact sheet on managing sediment in Catskill streams has been published by Cornell Cooperative Extension of Ulster County for the Ashokan Watershed Stream Management Program (AWSMP). It is available for free download at https://ashokanstreams.org/publications-resources/. The Sediment Management Stream Guide was written for streamside landowners, elected municipal officials, and anyone interested in stream science, watershed planning, and current best practices in stream management.
The Sediment Management Stream Guide outlines some of the basic physics that control sediment movement in stream channels, looks at the history of sediment management activities, and provides guidance on current best management practices.
Up until the 1950s, stream sediment was often dredged, or mechanically removed, with support from federal and state agencies to reduce flooding by enlarging the stream channel. By the 1960s it became clear that even well-intentioned dredging projects were limited in their long-term effectiveness and had negative consequences for fisheries, water quality, and stream channel stability. Dredging to manage sediment is also a costly and repetitive process, often paid for by local governments and taxpayers.
The Sediment Management Stream Guide makes the distinction between dredging and engineered sediment removal as part of stream channel restoration. Dredging enlarges the stream channel. The problem is that channel excavation often leads to increased erosion of the bed and banks that threatens roads, properties, and infrastructure. In addition, an overly large channel lacks the power necessary to move sediment and fills back in after the next high flow event. Engineered sediment removal restores the stream’s naturally stable channel dimensions. A properly sized channel can move much of the sediment load on its own, reducing the need for repetitive maintenance. If tempted to make the stream wider, the Stream Guide recommends the modern engineering practice of widening the floodplain instead of the channel.
Find the AWSMP Sediment Management Stream Guide for free at:
There are several other Stream Guides, as well as Stream Management Plans and The Ashokan Watershed Adventure guide, a self-guided tour of the Ashokan landscape available for free download at:
The AWSMP is a collaboration between the Ulster County Soil and Water Conservation District, Cornell Cooperative Extension of Ulster County, and NYC Department of Environmental Protection. The stream program office in Shokan, NY can be reached at (845) 688-3047 or firstname.lastname@example.org. For more information on outreach programs, funding, and stream projects go to www.ashokanstreams.org.
–Cornell Cooperative Extension of Ulster County