Erosion and Sediment Control on Construction Sites
What is erosion?
Soil erosion is the process of detachment and transportation of soil materials by water, wind, ice and gravity. Henrico County's Erosion and Sediment Control Program deals with erosion resulting from (water) raindrop impact on un-stabilized soil, primarily during the development process.
Erosion does occur naturally without requiring human action. This type of erosion is called "geologic" erosion, and according to the Virginia Department of Conservation and Recreation, produces about 30 percent of the total sediment load generated in the United States. Soil erosion resulting from people's use of land, called "accelerated" erosion, accounts for the remaining 70 percent. Surface mining, forestry, agriculture and construction are the major land use activities that cause "accelerated" erosion.
Henrico's erosion and sediment control program focuses primarily on construction activities. Erosion resulting from these activities can be 200 times greater than the amount of erosion generated from cropland and 2,000 times greater than that naturally occurring in woodlands.
Why is erosion and sediment a problem?
When natural landscape is converted to build houses, subdivisions, shopping centers, and roads, sediment results from erosion of disturbed soil. Sediment from construction sites is a major contributor to water pollution, flooding, stream channel damage, decreased groundwater storage, slope failures, damage to adjacent and/or downstream properties, as well as causes of project delays and increased project costs when these problem issues need to be addressed.
Successful minimization of these impacts can be achieved more cost effectively and efficiently by preserving the existing vegetation and minimizing the amount of land disturbed at one time on a site. However, when this is not practical or possible, installation of erosion and sediment control (ESC) measures such as silt fence, construction entrances, sediment basins, and especially temporary and permanent seeding is necessary to prevent soil movement/loss in the first place, enhance project aesthetics, reduce complaints, and most importantly, eliminate appreciable damage to off-site receiving channels, property and natural resources.
What activities are considered land disturbing?
Land-disturbing activity in Henrico County is defined as any clearing (including removal of trees), grading, excavating, transporting or filling of land or any other activity that removes vegetation, root mat or topsoil that may result in soil erosion from water or wind and the movement of sediments. In Henrico County, land-disturbing activities equal to or exceeding 2,500 square feet in area require an approved erosion and sediment control plan.
However, the following 13 activities are specifically exempt from the definition and the erosion and sediment control plan requirements:
If you are uncertain as to whether or not a specific activity is regulated, contact Mike Hackett, Senior Environmental Inspector at (804) 727-8328.