Groundwater-Dependent Ecosystem
Groundwater-dependent ecosystems are plant and animal communities that rely on groundwater for all or part of their water needs. This dependence may occur through shallow water tables accessible to roots, groundwater-fed springs, or baseflow contributions to rivers and wetlands.

Water Table
The upper surface of the zone of saturation in an unconfined aquifer.

Aquifer
An aquifer is the rocky structure underground that holds groundwater. Aquifers are filled when rain and melting snow sink into the earth. They provide California with about a third of its fresh water, including drinking water from wells and irrigation for farmlands. Growing demands for water are draining many aquifers because too much water is being pumped out before rain and melting snow can refill them.

Bedrock
Solid rock underlying loose deposits such as soil

Groundwater
Water from rain and melting snow that collects underground, where it can be pumped out for drinking or irrigation, or to supply water to the environment. For example: when we drink water from a well, we are drinking groundwater.

On-Farm Recharge
The replenishment or return of groundwater on working farmland; it can happen naturally in the ground when it rains or artificially by pumping water into the ground.

Wetland
Land or areas (such as marshes or swamps) that are often intermittently covered with shallow water or have soil saturated with moisture

Flow-Through Basin
Small, strategically placed floodplain features that divert high surface water flows to reduce local flood risk, recharge groundwater, and create seasonal, variable-depth habitat for riparian and wetland species.

Recharge Basin
A surface facility constructed to infiltrate surface water into a groundwater basin. Recharge basins are frequently used to recharge unconfined aquifers. Water is spread over the surface of a basin or pond in order to increase the quantity of water infiltrating into the ground and then percolating to the water table. Recharge basins concentrate a large volume of infiltrating water on the surface. As a result, a groundwater mound forms beneath the basin.

Clay Layer
Regionally continuous deposits of fine-grained sediments (primarily clay-sized particles) that function as low-permeability barriers within aquifer systems. Because they have very low hydraulic conductivity, they significantly restrict vertica

Domestic Well
Privately owned groundwater wells that supply water to individual households or small clusters of homes. They typically pump from shallow to intermediate-depth aquifers and serve low-volume uses such as drinking water, sanitation, and landscaping.

Agricultural Well
High-capacity groundwater wells designed to supply water for irrigation and livestock operations. They commonly pump large volumes from productive aquifers to meet seasonal crop water demands.

Community Water Supply
Agroundwater (or surface water) system that provides treated drinking water to a defined population through a centralized distribution network. When groundwater-based, these systems rely on wells and are managed to meet public health and reliability standards.

Bedrock
Solid rock underlying loose deposits such as soil.

Reservoir
A reservoir is a natural or constructed surface water storage basin that captures and retains runoff for later release or use

Conveyance
A conveyance provides for the movement of water, either natural or manmade. Conveyance infrastructures include natural watercourses, such as streams, rivers, and groundwater aquifers; and constructed facilities, such as canals and pipelines, including control structures such as weirs. Conveyance facilities range in size from small, local, end-user distribution systems to large systems that deliver water to or drain areas as large as multiple hydrologic regions.

Perched aquifer
A perched aquifer is a localized zone of groundwater supported by a zone of material of low permeability located above an underlying main body of groundwater.

Domestic Well (Dry)
Privately owned groundwater wells that supply water to individual households or small clusters of homes. They typically pump from shallow to intermediate-depth aquifers and serve low-volume uses such as drinking water, sanitation, and landscaping.