Streambank Erosion

Stream stability is an active process and while streambank erosion is a natural part of this process, it is often accelerated by altering the stream system, removing streamside vegetation, cumulative land cover changes in the watershed from forest to other vegetation and to hard surfaces such as roads, roofs, etc. Altering the natural system can result in erosion rates hundreds of times greater than those seen in naturally stable streams. Streambank erosion increases the sediment that a stream must carry, resulting in the loss of fertile bottomland and causes a decline in the quality of habitat on land and in the stream.

Streambank erosion is widespread in the Culpeper District, particularly since watershed destabilizing events that occurred in 1995 and 1996. The District has accomplished a few restoration projects over the past several years although a steady reliable source of funding for such projects is currently non-existent. Past projects have been funded by District sponsored grants, sometimes coupled with conservation incentive program funds and/or landowner contributions.

The District sponsored a workshop on stream restoration program opportunities in the fall of 2011 to better inform landowners of other opportunities to implement projects on their land. The presentations from this workshop are available by email.

A riparian buffer is an area of land adjacent to a body of water that is managed to minimize disturbance and promote the establishment of vegetation for the protection of stream banks. Buffer widths and type of vegetation are determined by local soils, hydrology and landowner objectives.

The ideal buffer width is 100 feet with two distinctive management areas; the Resource Protection Area (RPA); areas that protect and benefit water quality, and Resource Management Areas (RMA); areas with the potential to damage water quality without proper management.

The loss of the stream bank can threaten property, livestock and life. Stream bank erosion accounts for a majority of the sediment load in large rivers draining to the Chesapeake Bay. This increased sediment load smothers benthic macro-invertebrate and fish habitat. The suspended sediments can block sunlight from submerged aquatic vegetation and inject soil nutrients for algal blooms. The goal of most stream restoration projects undertaken by the District focuses on sediment reduction. Other government agencies such as the U.S. Fish and Wildlife Service and Virginia Department of Game & Inland Fisheries focus on restoring wildlife habitat.

Additional Resources

DEQ Stream Restoration Manual: http://www.deq.virginia.gov/Portals/0/DEQ/Water/Publications/BMPGuide.pdf

Stream Restoration Program at NC State: http://www.bae.ncsu.edu/programs/extension/wqg/srp/

DEQ Riparian Buffer Link: http://www.deq.virginia.gov/Portals/0/DEQ/Water/Publications/RiparianBufferManual.pdf

http://www.deq.virginia.gov/Portals/0/DEQ/Water/Publications/RPAFactSheet.pdf

VCE links: Resources for Virginia Landowners: https://pubs.ext.vt.edu/420/420-156/420-156_pdf.pdf

Planning Establishment and Maintenance: http://pubs.ext.vt.edu/420/420-155/420-155.html