What is NSCD?

Streams are complex ecosystems with morphological characteristics that are dependent on appropriate geomorphic dimension, pattern, and profile as well as biological and chemical integrity.  Proper stream function includes the transport of water and sediment produced by the stream’s watershed in dynamic equilibrium.

Natural stream channel design (NSCD) addresses the entire stream system.  It is based on fluvial geomorphology (FGM), which is the study of a stream’s interactions with the local climate, geology, topography, vegetation, and land use -- how a river carves its channel within its landscape.  The underlying concept of natural stream channel design is the use of a stable natural channel as a blueprint or template for the design of stream restoration projects.  This reference reach demonstrates the pattern, dimension, and profile required for the stream to transport its watershed’s flows and sediment as it dissipates energy through its particular geometry. 

NSCD is not a rigid “one size fits all” design package for natural stream restoration.  Each project’s design must be based on a particular reference reach that accurately reflects local fluvial geomorphology. 

Project elements, which may include changes in channel configuration, channel and/or bank structures, and nonstructural techniques, must support the stream’s function of transporting water and sediment.  In addition to stabilizing the stream channel, the project design should promote a high biological diversity and a stable riparian zone.

A small NSCD project was completed in 2004 along Fishing Creek in Columbia County, PA.  Constructed by the U.S. Fish and Wildlife Service, the project includes some of the typical elements of NSCD, including J-Hooks and Cross-Vanes, and some no-so-typical elements including a public park, a constructed wetland, and handicapped-access to the stream.

Fishing Creek (Kocher Park) Project