Reduce flood flows
Wetlands absorb initial surges in water flows along rivers. Floodplain wetlands provide larger areas to contain flood flows and reduce the effect of floods on downstream areas. In urban areas wetlands are particularly important as they can prevent damage to property from flood events.
Maintain baseflows
Wetlands store flows from rivers, flood events, rainfall runoff and snow melt, and slowly release water over time. This contributes to baseflow of rivers providing water in dry periods and preserving downstream aquatic ecosystems.
Facilitate groundwater recharge
Wetlands act like sponges, soaking up surface water from rainfall and floods. The water stored by wetlands can slowly infiltrate through the soil and unsaturated zone and recharge an underlying aquifer. As groundwater abstraction increases it is important that these contributions are maintained or augmented.
Improve water quality
Wetlands act as filters by slowing down incoming water flows, trapping contaminants within the vegetation and soil and allowing contaminants to settle in the soil or be taken up by vegetation, ultimately releasing water of improved quality.
Promote biodiversity
Wetlands provide a home for a variety of plant and animal life. Because wetlands are at the interface of aquatic and terrestrial ecosystems, they can harbour a variety of species. Insects, birds, amphibians, arachnids, mammals and plants all naturally occur in wetlands.