E
cosystem
servicesdelivered
Provisioning
Regulation & maintenance
Cultural
Abiotic
C
ontribution
topolicyobjectives
Water Framework Directive
Floods Directive
Birds & Habitats Directive
2020 Biodiversity Strategy
P
otential
biophysicaleffects
Runoff
Reducing pollution
Soil conservation
Habitat
Climate Change
High
Low
Medium
None
Wetlands function like natural sponges, storing water and slowly releasing it. A network of many small wetlands can
store
a large amount of water, depending on where and
how it is established. Some wetlands can resupply aquifers, while others are fed by groundwater moving upwards. Natural swamps have a large hydraulic resistance due to the
often dense vegetation, and are usually flat areas with only slight topographic variations, which contributes to
slowing runoff
. A study in Finland showed a case study wetland
to
reduce peak flows
by up to 38%, and
reduce stream discharge
by up to 47%.Wetland restoration may be combined with floodplain restoration or re-meandering
so as to reduce flood risks. In coastal areas, wetlands can support protection against sea storms and surges.
Wetlands contribute to improving the
physico-chemical quality
of surface water through encouraging settlement of particulate matter, denitrification and the uptake of
nutrients by vegetation. They create aquatic and riparian
habitat
and hold an important part of Europe’s biodiversity. They can also be important spawning areas for fish species.
Wetlands may account for 40% of the global reserve of
terrestrial carbon
and can make an important contribution to combating climate change, as long as they remain in
good status.Wetlands also provide
cultural benefits
, potentially providing large areas of natural habitat that is valuable for activities such as bird watching.
