What are Wetlands?

A wetland is an area between dry land and water that is regularly saturated with surface or ground water. The saturation of water determines how the soil develops and the types of plant and animal communities that can thrive in an on the soil. Wetlands may support both aquatic and terrestrial species. The prolonged presence of water creates conditions that favor the growth of specially adapted plants and promote the development of characteristic wetland soils. 

Wetlands can vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors.

Wetland 1
Wetland 2
Why are Wetlands Important?

Consider a wetland as a giant sponge, it slowly absorbs water and releases it as necessary. The sponge-like quality of wetlands allows them to return water to the ground during dry periods. Wetlands also decrease water's momentum as it travels toward the river. Less momentum in the water equates to reduced soil erosion. 
As wetlands slow the flow of water, they're able to filter the water. Water travels around plants and vegetation slowly and, as a result, any suspended sediment drops out of the flow.
Why Do We Need Wetlands? 

Wetlands are an incredibly valuable resource not only for the city, but for society as a whole. Wetlands contain a multitude of beneficial services such as the ability to decrease flooding, remove pollutants from water, recharge groundwater, buffer and protect terrestrial boundaries, provide habitat for wildlife, and serve important recreational and cultural functions. Loss of our wetlands could result in our city having to invest more money in drinking water treatment or higher costs to citizens for flood insurance.  
Wetland 3