Clean Water
Rainfall that reaches the ground can be absorbed into the soil or flow over the land. When a wetland is able to capture this water before it enters creeks, streams or rivers, it functions like a natural filter.
First, wetland plants slow the flow of water from the surrounding land. This prevents erosion and gives the roots of wetland plants more time to absorb the nutrients this water is carrying. This also allows suspended sediment to settle to the bottom of the wetland.
By storing water before releasing it slowly, wetlands recharge local groundwater supplies and prevent downstream flooding. By trapping nutrient and sediment pollution, wetlands send cleaner water downstream.
How Do Wetlands Filter Water?
As water flows into a wetland it encounters the the plants growing there. This slows the water down making it less likely to cause erosion.
The nutrient pollutants nitrogen and phosphorus are absorbed by the roots of the plants. This helps remove the nutrients before they flow into the Chesapeake Bay.
Since the flow of water slows down once it enters a wetland, any sediment (shown as dots) has time to settle at the wetland bottom. This cleans the water and keeps the sediment out of creeks and rivers downstream.
Wetland plants absorb carbon dioxide (CO2) from the atmosphere. CO2 is a greenhouse gas.
