Wetlands are ecosystems saturated with water, either seasonally or permanently.

UNESCO: UK National Commission for UNESCO - UNESCO Conventions, Recommendations & Declarations in the UK

Groundwater is also important in sustaining streams, lakes, wetlands, and associated ecosystems.

UNESCO: THEMES

In addition, EPA's and USDA's relevant authorities cover a range of natural resources and their supporting ecosystems, including waters, sediments, barrier islands, wetlands, soils, land management, air resources, and drinking water supplies.

WHITEHOUSE: Executive Order -- Gulf Coast Ecosystem Restoration

UNESCO-IHP through its networks and partners actively contributes to the implementation of the Ramsar Convention in particular by identifying and inventorying transboundary aquifers and groundwater dependent ecosystems that are vital for the conservation and wise use of wetlands and their resources.

UNESCO: MEDIA SERVICES