Alluvial aquifers with sustained surface water discharge downstream of dam

Alluvial aquifers are formed from particles such as gravel, sand, silt and/or clay deposited by fluvial processes in river channels or on floodplains. These deposits store and transmit water to varying degrees through inter-granular voids. These aquifers may have structures, such as dams, that modify the flow of both surface water and groundwater. Dams that provide a sustained release of surface water may increase recharge from the downstream channel into the alluvial aquifers, resulting in their saturation.

• Palustrine (e.g. swamps), lacustrine (e.g. lakes) and riverine (e.g. streams and rivers) wetlands on alluvial aquifers with sustained flow from dams may depend on the surface expression of groundwater from these underlying alluvial aquifers.

• Terrestrial vegetation on alluvial aquifers with sustained flow from dams may depend on the subsurface presence of groundwater, typically using deep roots to access groundwater in the capillary zone above the water table.

Pictorial conceptual model PDF