Erosion is a slow process that produces fast problems. On a disturbed construction site, soil that took millennia to form can leave in a single afternoon of rain. These are the consequences that follow.
The uppermost layer holds the organic matter, structure, and biology that let anything grow. Once it moves off site, restoring it means importing and amending soil — an ongoing cost long after the project closes out.
Soil leaving a site has to land somewhere. It fills channels, reduces detention basin capacity, smothers stream beds, and raises the cost of downstream maintenance for whoever owns it.
Suspended sediment blocks light, raises water temperature, and carries attached nutrients and pollutants. Turbidity is both a visible symptom and a regulated one.
Fine sediment fills the gravel spaces where fish spawn and where aquatic insects live. The effect on a stream’s ecology persists for years after the source is stopped.
Choked channels and silted-in culverts carry less water. Capacity lost to sedimentation shows up as flooding at the next large storm, often well away from where the erosion occurred.
Visible sediment leaving a site is the most common construction stormwater violation there is. Stop-work orders, notices of violation, and penalties cost far more than the silt fence and matting that would have prevented them.
Every one of these is preventable with a real erosion control plan, installed before ground is broken and maintained until the site is stabilized.