Stormwater runoff containing toxic substances, fertilizer, pesticides, and particulates
Before human interference, most rainfall in the Lagoon’s watershed fell onto naturally vegetated upland habitats, where much of the precipitation was taken up by plants – the remainder percolated slowly through permeable soils into the lagoon. Rainfall was naturally scrubbed of contaminants through the percolation process, and was relatively clean when it entered the lagoon. Today, impermeable surfaces – roads, parking lots, and rooftops – cover much of the area where this natural cleaning process once occurred. During rain events, large volumes of stormwater runoff flow rapidly into swales, canals and ditches, carrying sediments, decomposed organic matter, nutrients, heavy metals, viruses, bacteria, and other pollutants directly into the Lagoon where they can sicken wildlife.