All materials for constructing the knowledge representing water (surface and subsurface) features; i.e., anything to do with water and water networks (hydrology).
These generally come from individual states, though there are national aquifer maps and efforts to create nationwide water well databases.
This information comes primarily from USGS NHDPlus data (NHDWaterbody and NHDFlowline).
How surface waterbodies connect so water can flow. This is modeled from USGS NHDPlus data (NHDFlowline).
Flowlines are one representation of catchments - they have a single inflow and a single outflow point.
Broader than catchments, watersheds may have multiple inflow points. They are most similar to dendritic catchments. Data comes from the Watershed Boundary Dataset (WBD).
Drinking water is generally sourced from aquifers via wells and/or from surface water bodies.
The Safe Drinking Water Information System (SDWIS) provides data on public water systems, community water systems, and both transient and non-transient non-community water systems.
These are areas around water intake points (groundwater or surface water) from which water may seep into aquifers or flow into surface water bodies.