Wetlands, by definition, are characterized by water saturation in the root zone, at, o r above the soil surface, for a certain amount of time during the year. Wetlands store precipitation and surface water and then slowly release the water into associated surface water resources, ground water, and the atmosphere. For example, wetlands that are near a topographical height, such as a mountain bog, will not receive as much runoff as a marsh in a low area amidst fields.
Wetlands can be precipit ation dominated, ground water dominated, or surface flow dominated.
Wetlands on local topographic heights are often precipitation dominated. Precipitation dominated wetlands may also be in flat or slightly elevated areas in the la ndscape, where they receive little or no surface runoff. Generally such wetlands have a clay and peat layer that retains the precipitation and also prevents discharge from ground water. Wetlands also form in landscape positions at which the water table actively discharges, particularly at the base of hills and in valleys. Such ground water dominated wetlands may also receive overland flow but they have a steady supply of water from and to groundwater.