Trees, shrubs, and other types of vegetation create a filter strip along waterways. These “streamside forests” are made up of plants that line the waterway from the impacts of surrounding land use.
The plants prefer moist to very wet soil and can withstand the disturbance of water flowing over and around them.
There are many functions attributed to the vital and beneficial resources that are streamside forests.
There are many land use activities that impact riparian buffers. The development of land that changes forest acreage to residential,commercial and industrial uses negatively influences the health of riparian forest buffers. For example, an increase in the amount of impervious surfaces(such as roads, parking lots, etc) in a watershed also increases the volume and velocity of water directed into streams through storm drains and other storm water management structures. This is due to the fact that the trees, plants and soil that once slowed and absorbed the water are no longer there. This increased volume and velocity promotes soil erosion from stream banks and results in the undercutting of mature trees which are important to riparian buffer zones.
When riparian buffers are lost, the unique functions and benefits they provide are also lost. Although mature trees cannot be replaced in size and density, reforestation can provide for the future. There are many reforestation projects going on throughout the state of Virginia. The Virginia Department of Forestry (VDOF) sponsors a Riparian Reforestation Project in Fairfax, County, Virginia. The Difficult Run Watershed is the focus for the project.
The Difficult Run Watershed is the largest watershed in Fairfax County, Virginia. There is a strong and impressive history that is associated without the Difficult Run stream. The Historical Society of Fairfax County has documented the presence of at least six mills within the Difficult Run watershed between 1784 and 1920. These bore the names of some of the early settlers within the county such as, Hunter's Mill, Waple's Mill, Fox's Mill Broadwater's Mill and Tolston's Mill. The desire to make the mills accessible helped formulate some of the major road systems in the county. Today some of the most heavily traveled roads in the county bear the names of these mills.
The Difficult Run Watershed collects drainage from 565,666 acres of land. Land use within this watershed is constantly changing from forested areas to urban community land use. This is having adverse effects on water quality and other environmental components. Difficult Run is a direct tributary of the Potomac River and this has an influence on water quality within the Chesapeake Bay.
Trees are considered valuable in the control of nonpoint source pollution. Since 1993, floodplain areas of Difficult Run have been enhanced by the planting of over 8,000 tree seedlings which have been planted through the cooperation of the Difficult Run Riparian Forest Restoration Project, VDOF, Fairfax Releaf and The Fairfax County Park Authority.
The objectives of the Difficult Run Riparian Restoration Project are:
This Difficult Run Urban Riparian Web Page portion of the VDOF Web Site was funded, in part, by the Virginia Coastal Resources Management Program at the Department of Environmental Quality through Grant #NA670Z0360 of the National Oceanic and Atmospheric Administration, Office of Ocean and Coastal Resource Management, under the Coastal Zone Management Act of 1972, as amended.