Hydrohistorian
Log in

← Groundwater

Groundwater monitoring wells

The wells the Division of Water Resources measures water levels in, by water district. A monitoring well is neither a permit nor a decree — it is a hole the state reads the water table from — and its page shows the readings, the aquifer DWR assigns it, and where the record is long enough, whether the level is rising, falling or flat.

34,303monitoring wells
22,521with at least one reading
1,014,049readings
72water districts

Browse by water district

Counts are what this site holds in its cache of DWR’s groundwater-level service: 11,782 of the wells DWR lists carry no reading here, and 12,191 carry exactly one — a trend needs at least 20 readings over 10 years, so most wells have none. A district’s own page draws these on its Groundwater tab. Source: DWR HydroBase, groundwater water-level wells and measurements.