The biggest influencing factor on stormwater runoff is the presence of impervious surfaces, which are any surface coverings that do not absorb water, including roads, roofs, and parking lots. As a result, water cannot soak into the ground, and instead drains into the stormwater system, and then our creeks and rivers, much faster then it naturally would. This rapid drainage, along with the increased quantity of runoff results in high peak flows in waterways during storms, causing severe erosion of stream banks, scouring of stream beds, excessive sedimentation, and flooding.
In urban environments such as Charlottesville, large areas are covered with impervious surfaces. There are almost 99 million square feet of impervious surface in the City. That is enough to cover over 1,700 football fields!