Newport News Times –
Across North America, rivers have been simplified and degraded by the systematic and widespread removal of beaver and large woody debris. Many streams are now no more than deep channels that don’t spread out floodwaters or create good salmon habitat.
Consequently, one of the major goals of the MidCoast Watersheds Council’s work and that of other similar groups and agencies is to restore the natural processes that large wood and beavers used to create. To effect meaningful salmon restoration, it is important to learn how to do this work over a large scale and lower cost. NOAA’s Research Fisheries Biologist, Dr. Chris Jordan, will discuss low-tech, “process-based” restoration methods at the Nov. 7 MidCoast Watersheds Council Community Meeting in Newport.
Historically, beaver dams and large woody debris were ubiquitous throughout North American rivers. Beavers often built their dams on large logs that would be stable even through winter storms. Their dams exerted a major influence on streams by elevating water tables, capturing sediments and slowing waters so the stream channels could overflow the banks into wetlands and floodplains to reduce downstream flooding, and conversely increasing flows during periods of drought. Large woody debris has been shown to similarly influence water flow and sediment and erosional processes. Salmon evolved under these conditions, with both the wood and beaver dams creating ideal fish spawning and rearing habitat.