How do wetlands help to improve water quality?
Wetlands improve the quality of water flowing over and through them, a critical role in nature’s own water quality restoration process. Wetland vegetation slows water flow and captures sediment suspended in the water, reducing turbidity, that murky quality that makes some waters unattractive for swimming and other recreation uses. Wetlands also filter out, trap and naturally recycle nutrients like nitrogen and phosphorous that run off from the land and might be harmful in excessive quantities in surface waters. This filtration process saves millions of dollars that might otherwise be required to build and operate facilities to perform this function. Wetlands can also capture pollutants like heavy metals, organic chemicals like pesticides and petroleum hydrocarbons, removing them at least temporarily and sometimes permanently from aquatic ecosystems. Unfortunately, when wetlands accumulate them, these harmful compounds can also enter the food chain through wetland vegetation and wildlif
